ArticleLiterature Review

Mother–infant cosleeping, breastfeeding and sudden infant death syndrome: What biological anthropology has discovered about normal infant sleep and pediatric sleep medicine

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Abstract

Twenty years ago a new area of inquiry was launched when anthropologists proposed that an evolutionary perspective on infancy could contribute to our understanding of unexplained infant deaths. Here we review two decades of research examining parent-infant sleep practices and the variability of maternal and infant sleep physiology and behavior in social and solitary sleeping environments. The results challenge clinical wisdom regarding "normal" infant sleep, and over the past two decades the perspective of evolutionary pediatrics has challenged the supremacy of pediatric sleep medicine in defining what are appropriate sleep environments and behaviors for healthy human infants. In this review, we employ a biocultural approach that integrates diverse lines of evidence in order to illustrate the limitations of pediatric sleep medicine in adopting a view of infants that prioritizes recent western social values over the human infant's biological heritage. We review what is known regarding infant sleeping arrangements among nonhuman primates and briefly explore the possible paleoecological context within which early human sleep patterns and parent-infant sleeping arrangements might have evolved. The first challenges made by anthropologists to the pediatric and SIDS research communities are traced, and two decades of studies into the behavior and physiology of mothers and infants sleeping together are presented up to the present. Laboratory, hospital and home studies are used to assess the biological functions of shared mother-infant sleep, especially with regard to breastfeeding promotion and SIDS reduction. Finally, we encourage other anthropologists to participate in pediatric sleep research using the unique skills and insights anthropological data provide. By employing comparative, evolutionary and cross-cultural perspectives an anthropological approach stimulates new research insights that influence the traditional medical paradigm and help to make it more inclusive. That this review will potentially stimulate similar research by other anthropologists is one obvious goal. That this article might do so makes it ever more possible that anthropologically inspired work on infant sleep will ultimately lead to infant sleep scientists, pediatricians, and parents becoming more informed about the consequences of caring for human infants in ways that are not congruent with their evolutionary biology.

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... In Euro-American settings, this has been most extensively studied in the context of mother-infant cosleeping and breastfeeding. Mothers and infants sleep together in many societies around the world and infants would have shared a sleeping surface with mothers (and likely others) throughout human evolution (Ball and Volpe, 2013;Crittenden et al., 2018;McKenna et al., 2007). Foundational laboratory research in the U.S. showed that breastfeeding mothers in routinely bedsharing dyads transiently awoke more often than routine solitary sleeping mothers but did not differ for nighttime sleep time or efficiency (McKenna et al., 2007). ...
... Mothers and infants sleep together in many societies around the world and infants would have shared a sleeping surface with mothers (and likely others) throughout human evolution (Ball and Volpe, 2013;Crittenden et al., 2018;McKenna et al., 2007). Foundational laboratory research in the U.S. showed that breastfeeding mothers in routinely bedsharing dyads transiently awoke more often than routine solitary sleeping mothers but did not differ for nighttime sleep time or efficiency (McKenna et al., 2007). Similar patterns were later found in an actigraphy-based study of solitary and cosleeping mothers and infants in Israel (Volkovich et al., 2015). ...
... In the present study, we examined social correlates of sleep time and quality using actigraph-based data from BaYaka adults, who are members of a foraging society in Republic of the Congo. We focused on aspects of shared social sleep environments and psychosocial dynamics that have been linked to lower sleep quality in past research in industrialized and post-industrialized settings, particularly household crowding, parent-infant cosleeping, and marital conflict (Ball and Volpe, 2013;Jackson, 2019;McKenna et al., 2007;Troxel, 2010). BaYaka adults slept less and had lower sleep quality when sleeping in more crowded conditions, paralleling a small body of prior work (Jackson, (Gordon et al., 2021;Troxel, 2010). ...
Article
Given the contributions of sleep to a range of health outcomes, there is substantial interest in ecological and environmental factors, including psychosocial contexts, that shape variation in sleep between individuals and populations. However, the links between social dynamics and sleep are not well-characterized beyond Euro-American settings, representing a gap in knowledge regarding the way that local socio-ecological conditions interrelate with sleep profiles across diverse settings. Here, we focused on data from a subsistence-level society in Republic of the Congo to test for links between the household/family social environment and sleep measures. Specifically, we used actigraphy-derived sleep data (N = 49; 318 nights) from two community locations (a village and rainforest camp) among BaYaka foragers, who are members of a remote, non-industrialized subsistence society in the Congo Basin. We drew on social dynamics that have been previously linked to sleep variation in Euro-American contexts, including: household crowding, same surface cosleeping, and marital conflict. We examined the following sleep measures: total sleep time (TST), total 24-hour sleep time (TTST), and sleep quality (fragmentation). BaYaka adults had shorter and lower quality sleep when their shared sleeping space was more crowded. In the village, parents with breastfeeding-aged infants had longer TTST and higher quality sleep than adults without infants, contrasting with results from other cultural contexts. Based on peer rankings of marital conflict, husbands showed longer and higher quality sleep in less conflicted marriages. In total, these results point to the importance of considering local socio-ecological conditions to sleep profiles and underscore the need for expanded study of sleep and health outcomes in settings where shared sleep in constrained space is routine practice.
... Our developmental trajectory specifically includes a stage of hyper-dependence in infancy, during which human babies experience extensive post-natal brain growth and development and remain fully reliant on caregivers for their survival and safety, while also receiving physiological input and regulation (e.g. respiration, heart rate, sleep state) from caregivers during both daytime and nighttime contact, proximity and care behaviors [5][6][7][8][9]. Evolutionarily, hominin infants would have had their nutritional needs met via breastfeeding during this developmental period. ...
... Because human breastmilk is relatively dilute (i.e. low in energy density), it is likely that hominin babies would have typically remained in close proximity to their mothers for frequent feedings across the 24-h day, including during nighttime sleep, as is the case in most other primates [6,[10][11][12]. ...
... Drawing on such cross-species insights as well as crosscultural perspectives, evolutionary medicine and anthropological research has been foundational to the study of the mutual dependence of human breastfeeding and mother-infant sleep proximity, including on shared sleep surfaces, which is characterized by the recently proposed concept of 'breastsleeping' [6,11,13,14]. Given its phylogenetic underpinnings along with the extreme dependency of human infants, the breastsleeping environment is argued to be the sleep ecology to which human babies are adapted evolutionarily [6,11,13,14]. ...
Article
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Background and objectives: Evolutionary-grounded sleep research has been critical to establishing the mutual dependence of breastfeeding and nighttime sleep proximity for mothers and infants. Evolutionary perspectives on cosleeping also often emphasize the emotional motivations for and potential benefits of sleep proximity, including for parent-infant bonding. However, this potential link between infant sleep location and bonding remains understudied for both mothers and fathers. Moreover, in Euro-American contexts bedsharing has been linked to family stress and difficult child temperament, primarily via maternal reports. We know relatively little about whether paternal psychosocial dynamics differ based on family sleep arrangements, despite fathers and other kin often being present in the cosleeping environment across cultures. Here, we aim to help address some of these gaps in knowledge pertaining to fathers and family sleep arrangements. Methodology: Drawing on a sample of Midwestern U.S. fathers (N=195), we collected sociodemographic and survey data to analyze links between infant nighttime sleep location, paternal psychosocial well-being, father-infant bonding, and infant temperament. From fathers' reports, families were characterized as routinely solitary sleeping, bedsharing, or roomsharing (without bedsharing). Results: We found that routinely roomsharing or bedsharing fathers, respectively, reported stronger bonding than solitary sleepers. Bedsharing fathers also reported that their infants had more negative temperaments and also tended to report greater parenting-related stress due to difficulties with their children. Conclusions: These cross-sectional results help to highlight how a practice with deep phylogenetic and evolutionary history, such as cosleeping, can be variably expressed within communities with the potential for family-dependent benefits or strains.
... In this chapter we first provide an overview of key findings from early and more recent work in biocultural anthropology, followed by a synthesis of ethnographic research. We conclude with our thoughts on how incorporating the study of infant sleep loss of mutual physiological regulation from mother-infant sleep proximity (McKenna, Ball, and Gettler 2007). ...
... The arguments that mother-infant co-sleeping is a central component of the evolved human behavioural repertoire of infancy and, as such, is unlikely to be expunged from contemporary parental practice has served as a counterpoint to US medical recommendations that view co-sleeping solely as a threat to infants. Because outcomes associated with bedsharing depend on the conditions and circumstances within which the bedsharing takes place, our research as to whether bedsharing can protect against rather than increase rates of SIDS or suffocation has led ultimately to an understanding of the critical importance of breastfeeding and its functional interconnections to bedsharing (McKenna, Ball, and Gettler 2007;Ball, Tomori, and McKenna 2019;Marinelli et al. 2019;Blair et al. 2020). ...
Chapter
The chapter synthesizes research on infant sleep in biological and sociocultural anthropology. We first describe an early phase in which the evidence base was established to support the position that parent–infant sleep proximity and lactation are intertwined normative adaptations within human evolution. This argument challenged the biomedical pediatric focus of the time, which used Western formula-fed infants sleeping separately from their parents as the basis for ostensibly universal models of human infant sleep. The subsequent phase of biological anthropology research advanced the understanding of parent–infant sleep and night-time care by incorporating behavioral ecology, hormonal measures, and parent–infant conflict theory. The impact of these two phases of research has extended beyond academia to influence policy and practice in the US, UK, and beyond. The focus on infant sleep within sociocultural anthropology has a more recent history. This research situates the biomedicalization of infant sleep within Western cultural frames that emphasize infant independence and the regimentation of maternal and infant bodies. We highlight ethnographic findings that maternal–infant shared sleep while breastfeeding is a cultural and embodied norm. Although cultural assumptions about the safety and suitability of sleep proximity remain, integrated anthropological approaches to infant sleep have the potential to contribute to maternal–infant health and well-being.
... Co-sleeping both with children and other adults is a valued cultural practice in many societies and is also often a necessity for households in which indoor sleeping space is limited, as is common among mobile foragers 6,26 . Among the Hadza of Tanzania, actigraphic analysis revealed that co-sleeping with a breastfeeding infant was not linked to altered sleep duration in mothers, but a higher number of co-sleepers was correlated with shorter sleep duration and quality 27 . ...
... Conversely, women exhibited longer, higher quality sleep throughout the night in the forest location. This is surprising, given that a total of 5 women in the forest were breastfeeding and cosleeping with infants under two years old, which has been linked to more frequent nighttime arousals in mother-infant dyads in the global North 22,26,37 . The proportion of breastfeeding women (42% of women in the village, and 38% of women in the forest) are roughly equivalent, and thus likely do not explain the locational gender-based differences in sleep duration and quality. ...
Article
Full-text available
Sleep studies in small-scale subsistence societies have broadened our understanding of cross-cultural sleep patterns, revealing the flexibility of human sleep. We examined sleep biology among BaYaka foragers from the Republic of Congo who move between environmentally similar but socio-ecologically distinct locations to access seasonal resources. We analyzed the sleep–wake patterns of 51 individuals as they resided in a village location (n = 39) and a forest camp (n = 23) (362 nights total). Overall, BaYaka exhibited high sleep fragmentation (50.5) and short total sleep time (5.94 h), suggestive of segmented sleep patterns. Sleep duration did not differ between locations, although poorer sleep quality was exhibited in the village. Linear mixed effect models demonstrated that women’s sleep differed significantly from men’s in the forest, with longer total sleep time (β ± SE = − 0.22 ± 0.09, confidence interval (CI) = [− 0.4, − 0.03]), and higher sleep quality (efficiency; β ± SE = − 0.24 ± 0.09, CI = [− 0.42, − 0.05]). These findings may be due to gender-specific social and economic activities. Circadian rhythms were consistent between locations, with women exhibiting stronger circadian stability. We highlight the importance of considering intra-cultural variation in sleep–wake patterns when taking sleep research into the field.
... The rise of industrialization, which brought about permanent dwellings, cribs, and alternative feeding options, was accompanied by shifting societal values (Mileva-Seitz et al., 2017). Shaped by medical recommendations (e.g., correlational links between bed-sharing and sudden infant death syndrome) (Vennemann et al., 2012) and parental and professional beliefs (e.g., interference with partner intimacy, decreases child autonomy) (McKenna et al., 2007;Okami et al., 2002;Owens, 2002), bed-sharing was no longer essential for infant survival and Western nations transitioned toward separate sleep surfaces for infants (McKenna et al., 2007). ...
... The rise of industrialization, which brought about permanent dwellings, cribs, and alternative feeding options, was accompanied by shifting societal values (Mileva-Seitz et al., 2017). Shaped by medical recommendations (e.g., correlational links between bed-sharing and sudden infant death syndrome) (Vennemann et al., 2012) and parental and professional beliefs (e.g., interference with partner intimacy, decreases child autonomy) (McKenna et al., 2007;Okami et al., 2002;Owens, 2002), bed-sharing was no longer essential for infant survival and Western nations transitioned toward separate sleep surfaces for infants (McKenna et al., 2007). ...
Chapter
Over the past two decades, there has been heightened interest and awareness of the impact that sleep has on children's development, learning, mood, and behavior. Clinical services for pediatric sleep disorders are increasingly available and there has been a proliferation of research related to sleep disturbances in children. This article was designed to provide a broad overview of common sleep problems and their treatments in youth. Pediatric sleep medicine is a rapidly developing field with abundant opportunities for expanding our scientific understanding of sleep disorders and creating novel interventions for children and adolescents with disturbed sleep.
... All items were coded so that higher scores indicated more depressive symptoms. A cut-off indicating probable depression has been suggested at 12-13 points [47]. Here, we used a continuous measure of PPD 'symptoms' and not a categorical measure based on the diagnostic cut-off. ...
... Another possible explanation for the association between infant night waking and PPD symptoms could be derived from the mismatch hypothesis about recent shifts in human lifestyle [11]. Contrary to the mismatch hypothesis, we did not, however, find any strong support for differences between co-sleepers and mothers who slept separately from their infants (with co-sleeping more closely resembling ancestral lifestyles) [47]. Other potential mismatch factors that contribute to PPD, such as changes in family networks postpartum and observed differences in immune function between women in industrialized environments [48], were not tested here but warrant further investigation. ...
Article
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Background and objectives As the mother-offspring relationship is central to human reproduction, postpartum depression symptoms are difficult to explain in evolutionary terms. We proposed that postpartum depression might arise as a result of evolutionary mother-offspring conflict over maternal investment, and investigated the association between postpartum depression symptoms, infant night waking, maternal sleep disturbance and breastfeeding frequency. Methodology We conducted a cross-sectional analysis using survey responses at six months postpartum from 1598 Finnish mothers. We hypothesized that infant night waking at six months postpartum would be associated with postpartum depression symptoms, and that this association would be mediated by maternal sleep disturbance and a higher breastfeeding frequency. Results Infant night waking was moderately associated with postpartum depression symptoms, and this association was mediated by maternal sleep disturbance (R2 = .09). Contrary to our prediction, we found that increased breastfeeding was associated with less postpartum depression symptoms. Conclusions and implications We conclude that postpartum depression symptoms might partly be the result of increased maternal fatigue stemming from high offspring demands on maternal investment, but that this is not due to the metabolic strain from increased breastfeeding. Studying postpartum depression from the mother-offspring conflict perspective can potentially improve our understanding of the involved behavioral processes of both mother and offspring, and allow interventions designed to benefit the well-being of both parties.
... All items were coded so that higher scores indicated more depressive symptoms. A cut-off indicating probable depression has been suggested at 12-13 points [47]. Here, we used a continuous measure of PPD symptoms and not a categorical measure based on the diagnostic cut-off. ...
... Another possible explanation for the association between infant night waking and PPD symptoms could be derived from the mismatch hypothesis about recent shifts in human lifestyle [11]. Contrary to the mismatch hypothesis, we did not, however, find any strong support for differences between cosleepers and mothers who slept separately from their infants (with co-sleeping more closely resembling ancestral lifestyles; [47]). Other potential mismatch factors that contribute to PPD, such as changes in family networks postpartum and observed differences in immune function between women in industrialized environments [48], were not tested here but warrant further investigation. ...
Preprint
Background and objectives: As the mother-offspring relationship is central to human reproduction, the high incidence of postpartum depression symptoms is difficult to explain in evolutionary terms. We proposed that postpartum depression might be the adverse result of evolutionary mother-offspring conflict over maternal investment, and investigated the association between postpartum depression symptoms, infant night waking, maternal sleep disturbance and breastfeeding frequency. Methodology: We conducted a cross-sectional analysis using survey responses at six months postpartum from 1598 Finnish mothers. We hypothesized that infant night waking at six months postpartum would be associated with postpartum depression symptoms, and that this association would be mediated by maternal sleep disturbance and a higher breastfeeding frequency.Results: Infant night waking was associated with postpartum depression symptoms, and this association was mediated by maternal sleep disturbance. Contrary to expectations, we found that the increased breastfeeding was associated with less postpartum depression symptoms. Conclusions and implications: We conclude that postpartum depression symptoms might be the result of increased maternal fatigue stemming from high offspring demands on maternal investment, but that this is not due to the metabolic strain from increased breastfeeding. Studying postpartum depression from the mother-offspring conflict perspective improves our understanding of the involved behavioral processes of both mother and offspring, and thus allows interventions designed to improve the well-being of both parties.
... [171,172]). But parentinfant separation arises regularly with sleep, at least in European-American cultures where sleeping apart prevails [173]. To cope with this recurrent transition, infants frequently rely on odorous 'sleep-aids' ( pieces of cloth, fluffy objects or their own hands; e.g. ...
... The mother's odour appears to be effective in her absence, and thus may be an efficient regulator of calm and sleep in infants left alone. One experiment [173] explored this hypothesis longitudinally in infants aged 3, 6, 9 and 12 months who slept alone with a t-shirt containing the mother's odour, and did not find that the t-shirt was privileged in inducing soothing, but (suboptimally) only renewed the odour stimulus every month. ...
Article
Full-text available
The impact of the olfactory sense is regularly apparent across development. The fetus is bathed in amniotic fluid (AF) that conveys the mother’s chemical ecology. Transnatal olfactory continuity between the odours of AF and milk assists in the transition to nursing. At the same time, odours emanating from the mammary areas provoke appetitive responses in newborns. Odours experienced from the mother’s diet during breastfeeding, and from practices such as pre-mastication, may assist in the dietary transition at weaning. In parallel, infants are attracted to and recognize their mother’s odours; later, children are able to recognize other kin and peers based on their odours. Familiar odours, such as those of the mother, regulate the child’s emotions, and scaffold perception and learning through non-olfactory senses. During juvenility and adolescence, individuals become more sensitive to some bodily odours, while the timing of adolescence itself has been speculated to draw from the chemical ecology of the family unit. Odours learnt early in life and within the family niche continue to influence preferences as mate choice becomes relevant. Olfaction thus appears significant in turning on, sustaining and, in cases when mother odour is altered, disturbing adaptive reciprocity between offspring and carer during the multiple transitions of development between birth and adolescence. This article is part of the Theo Murphy meeting issue ‘Olfactory communication in humans’.
... Con icts between societal expectations and feeding physiology continue a century after the infant feeding contributors that Wolf chronicled. Individuals regarded as parenting experts throughout the twentieth century recommended scheduled feedings at intervals incompatible with exclusive breastfeeding, which is summarized by Ball (2007). Baby supply stores now teem with swaddle wraps, swings, shushing machines, paci ers, and other devices that claim to obviate the need for infants to be held and fed at physiologically normal intervals. ...
... A Google search for "my newborn doesn't sleep at night" yields 58.8 million results; an Amazon search for "baby sleep" yields more than 100,000 results. Infant sleep engenders considerably controversy, with some arguing that efforts to limit nighttime parenting adversely affects child stress reactivity and that deep, prolonged infant sleep may actually contribute to SIDS risk (McKenna, Ball, & Gettler, 2007;McKenna & McDade, 2005), and others that responding to night waking exhausts parents with limited bene t to the child. From an evolutionary standpoint, these debates re ect an ancient con ict between parent and offspring, in which trade-offs depend on relative risks within the current ecological context. ...
Chapter
Full-text available
In this chapter, we use an evolutionary lens to deepen understanding of maternal and family needs in the early postpartum period so that health care can be more aligned with confronted realities. The discussion is centered around the concept of the 4th trimester, which is the period between birth and the first 3 months postpartum. This framework encourages a holistic understanding of perinatal health by drawing attention to evolved maternal-infant needs. By addressing these ultimate-level contributors to health issues, we can facilitate more effective clinical support, comprehensive research, and a fuller “village” to enable new families to thrive. Core to this approach is the concept of trade-offs between parents and offspring, exemplified by lactation as a prime example of the complexities of dyadic needs and gap between the current culture of health and optimal support.
... The weakest study in relation to confounding was that of Narangerel et al. (22) which not only failed to allocate participants randomly but also failed to ascertain infant feeding method and whether the sleep studied was nocturnal, diurnal or both. An investigation of sleep and arousal cannot be effective when analyzed in isolation from these key factors (31,32). ...
Article
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Background: Western parents swaddle infants to promote sleep and reduce night-waking, however recent evidence of the effects of swaddling on the sleep of healthy infants has not been systematically reviewed. Objective: To investigate the effect of swaddling on the sleep of infants up to 1 year of age using a narrative synthesis approach. Data sources: We systematically searched five academic databases, including the Cochrane trial registry (Pubmed, PsycINFO, Embase, the Cochrane library, and Blackwell Synergy). We manually searched reference lists and citations of included studies and reference lists of existing reviews. Study selection: Studies of any type, published since 2007, reporting primary data whose subjects were humans up to 12 months of age with outcome measures relating to the impact of swaddling on sleep and arousal. Data extraction: By hand using a customized template. A narrative synthesis is used to present the results. Results: In total 171 studies were retrieved with 115 studies discarded at title. A further 43 were discarded at abstract, and six were discarded at full text. Two papers were combined as they reported on the same study giving a total of 6 studies that met the inclusion criteria for the review. An evidence hierarchy was used to assess Risk of Bias in the included studies; the results are presented via a narrative synthesis. Swaddling was associated with increased duration of quiet sleep in infants and a significantly reduced number of sleep state changes among infants naïve to the intervention. Limitations: The integrity of the intervention (swaddling) including its baseline characteristics, was defined broadly across the included studies limiting the interpretation and transferability of the results of this review. Conclusions: Swaddling appears to increase quiet sleep duration in infants and reduces the number of sleep state changes among infants naïve to the intervention. Parents should be made aware that implementing conditions unfavorable to arousability may increase SUDI risk among infant who have not previously been swaddled. This review has relevance for informing future practice recommendations and parent advice as well as in designing future studies.
... There is also evidence that breastfeeding may reduce the risk of sudden infant death syndrome (SIDS) with plausible biological mechanisms for this effect [93,94]. Cytokines and immunoglobulins may safeguard babies during the period when SIDS risk is greatest (2-4 months of age) [94]. ...
Article
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Globally, diarrheal diseases and acute respiratory infections are the leading causes of morbidity and mortality in children under 5 years old. The benefits of exclusive breastfeeding in reducing the risk of gastrointestinal and respiratory infections are well documented. Optimal breastfeeding may potentially save the lives of about 800,000 children in low-income settings. Despite the evidence, around 63% of infants from birth to 6 months are not exclusively breastfed worldwide. We searched the literature published between 2010 and 2022 in Medline, Embase, and Scopus on the association between exclusive breastfeeding and infectious diseases. We selected and reviewed 70 relevant studies. Our findings expand and confirm the positive association between exclusive breastfeeding and reduced risk of a number of gastrointestinal, respiratory, and other infections in 60 out of 70 studies observed in both low- and high-income settings. Several studies analyzing exclusive breastfeeding duration reported that a longer exclusive breastfeeding duration is protective against many infectious diseases. This review also reported a lack of standardized definition for measuring exclusive breastfeeding in many studies. Overall, the results highlight the benefits of exclusive breastfeeding in many studies and suggests reporting exclusive breastfeeding in future studies using a consistent definition to enable better monitoring of exclusive breastfeeding rates.
... Bedsharing in particular has been the subject of heated debate as a risk factor in the incidence of Sudden Infant Death Syndrome (SIDS) (American Academy of Pediatrics Task Force on Sudden Infant Death Syndrome, 2016). In sharp contrast, bedsharing has been touted by others as a beneficial practice that promotes breastfeeding and enables the parent to monitor the infant more closely during the night (McKenna et al., 2007). Although their cross-sectional design precluded causal inference, Wang et al. (2013) identified cosleeping as causal to disrupted sleep in the infant (Wang et al., 2013), and in their longitudinal study Teti et al. (2016) identified cosleeping as a marker and possible cause of family distress, especially if cosleeping is prolonged. ...
Article
The present study of 124 families examined linkages between patterns of sleep arrangement use across the first 6 months post-partum and (a) family socio-demographics, (b) nighttime sleep of infants, mothers, and fathers, and (c) coparenting distress, and mothers’ emotional availability with infants and bedtime. Families were recruited when infants were 1-month-old, and infants were classified, from video data available at 3 and 6 months post-partum, into one of three sleep arrangement pattern groups: Solitary sleep, cosleeping, and cosleeping (at 3 months)-to-solitary sleep (at 6 months). Mothers in cosleeping arrangements were more likely to be at higher socioeconomic risk, non-White, unemployed, and to have completed fewer years of education. Controlling for these variables and for duration of breast feeding and parental depressive and anxiety symptoms, subsequent 3 (sleep arrangement pattern) X 2 (infant age: 3 and 6 months) mixed-model analyses of covariance revealed that sleep arrangement patterns were more robustly linked with maternal sleep than with infant and father sleep. Mothers in cosleeping arrangements experienced more fragmented sleep and greater variability in fragmented sleep relative to mothers of infants in solitary sleep, and fathers in cosleeping arrangements showed greater variability across the week in the number of minutes of nighttime sleep. Cosleeping was associated with mother reports of less positive and more negative coparenting, and mothers in cosleeping arrangements were independently observed to be less emotionally available with their infants at bedtime compared to mothers in the other two sleep arrangement groups. These linkages were largely upheld after statistically controlling for mothers’ stated preference for sleep arrangements they were using.
... Japanese caregivers in daycare centres provide more direct physical contact with children when putting them to sleep, whereas their Scottish counterparts tend to rock children to sleep in a cot or buggy (Negayama & Kawahara, 2010). Thus, infant sleep is a significantly varying behaviour affecting the co-regulation of mother-infant distance (McKenna et al., 2007), that reflects cultural differences in mothers' infant-centredness. ...
Article
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Mothers and infants co-regulate their distance from one another at home. Continuous, naturalistic home observations of the changes in mother-infant distance were carried out in Japan and Scotland during infant ages of 0-1, 6-7, and 12-13 months. This study examined mutual distance-increasing and distance-reducing behaviours, referred to as parent-infant 'centrifugalism' and 'centripetalism'. Cultural differences emerged in the modes of mother-infant distance co-regulation. Scottish mothers were more active in initiating contact and leaving infants alone to sleep, whereas Japanese mothers showed stronger infant-centredness by maintaining physical contact with infants when they fell asleep and reacting to their crying when they woke up. Age differences were found relating to decrease in sleep and increase in object play in the middle of the first year, which resulted in more separation within a 0.5 m distance at 6-7 months, a compromise between closeness and distancing between mothers and awake infants. Cultural and age differences in the co-regulation of mother-infant distance were discussed in relation to the development of locomotion, object play, and intention-reading.
... 38 WEIRD societies value independence and selfreliance, making solitary sleeping arrangements desirable, but these may contradict biologically normative infant sleep patterns. 2,39 However, within Western culture, variations in personal beliefs and parenting choices can impact preferences for nighttime care. More attachment-style parenting 40 and cued-care parenting 41 styles focus on the need for nighttime responsiveness and proximity. ...
Article
Infant sleep problems are one of the commonly reported reasons parents seek professional help, yet what constitutes a “sleep problem” depends on the models used to explain the development of infant sleep. The current models are based on research conducted in the western context where infant solitary sleeping is the norm. Parent-child co-sleeping is the norm in many cultures around the world. We argue that the primary focus of current research on parent-child interactions as the mediating context for the development of infant sleep problems has inherently made these models and ensuing interventions less sensitive and applicable to infant sleep problems in the context of co-sleeping families. When families present for help with infant sleep difficulties, extinction based behavioral interventions or interventions focused on reducing parental presence at bedtime are commonly recommended. These recommendations may not always align with cultural values and parenting practices of all families, therefore precluding these families from getting necessary help. In attempting to provide families with choices that depart from behavioral based interventions, this paper draws on research and adapts current models to propose an alternative to conceptualize perceptions of infant sleep problems that may be sensitive to and applied across various cultural and personal contexts. We attempt to provide a rationale for interventions that are inclusive and sensitive to families where reduced parental nighttime responsiveness may not be a preferred choice.
... [1][2][3][4] At the same time, it is important to note that these models are incongruent with maternal-infant evolved biology, and differ from infant care in other societies and cultures where a vast majority of the global population resides. [5][6][7] Three decades ago saw the beginning of engagement by anthropologists with infant sleep. Solitary infant sleep practices were dominant in the anthropologists' own societies and they used this practice to judge other cultures even though this was considered to be an unusual and historically recent behaviour confined to a limited sub-group of cultures. ...
Article
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Purpose: To assess mothers' approaches to infant sleep practices. Patients and methods: A cross-sectional survey study was conducted on mothers with babies aged below five months who were attending paediatric clinics between November 1st, 2020, and January 5th, 2021, in Riyadh, Saudi Arabia. Results: A total of 522 mothers participated in this study. A total of 38.9% practised exclusive formula feeding. A total of 61.9% of the participants practised the supine position. The majority (93.3%) of the mothers shared a room with their babies, while 34.7% shared a bed. Only 6.9% did not use any soft bedding. Age was a significant predictor associated with participant practices regarding sleeping and feeding positions (p < 0.05). Having two or more children was associated with improper sleeping practices (p < 0.05). Being non-Saudi and having a university degree or higher were associated with having a higher risk of unsafe practices regarding bed-sharing (p < 0.05). On the other hand, being contacted by a doctor, nurse, or other healthcare worker about safe sleep practices were an important factor that influenced safe practices regarding feeding (p < 0.05). Receiving care at a private hospital was associated with safer practices regarding sleeping position and bed-sharing (p < 0.05). Conclusion: We observed high-risk sleeping practices among Saudi mothers. This includes using soft bedding and unsafe sleeping positions. The importance of this study lies in the future implementation of this result through public health measures aimed at at-risk populations.
... Los valores culturales cambiantes ponen cada vez más énfasis en el individualismo, el amor romántico y la santidad del matrimonio; la alimentación con biberón se convirtió en una alternativa viable de alimentación. Se comenzó a considerar compartir la cama como psicológicamente dañino (5). Desde el siglo XX hasta nuestros días, poner a los bebés a dormir en una superficie separada ha sido la norma en América del Norte, Europa y en algunas naciones asiáticas. ...
Article
El colecho es la práctica en la que el bebé duerme en la misma superficie que los padres. Esta es una práctica común en todo el mundo. A veces es una elección a conciencia y en otras ocasiones puede suceder cuando los padres están cansados. Los padres actualmente reciben mensajes contradictorios con respeto compartir la cama: “Debería dormir con su bebé” y que “es peligroso dormir juntos”. Aunque las madres que amamantan y comparten la cama se despiertan con frecuencia para alimentar al bebé, estas están despiertos por períodos más cortos y se vuelven a dormir más rápidamente. Compartir la cama es una estrategia utilizada por las madres que amamantan para reducir la interrupción del sueño y el desgaste físico que esto produce.
... Biological anthropologists are experts at teasing apart the complexities of biocultural interactions that inform what it is to be human, examining how broad-ranging factors such as market acculturation (Godoy et al., 2005;Liebert et al., 2013), parenting strategies (McKenna et al., 2007;Nelson, 2016), or socially constructed categories of race (Dressler & Bindon, 2000;Gravlee, 2009) relate to physiology including growth and development, immune function, and endocrinology. Yet we have not fully engaged with cutting-edge understandings of variation in gender, sex, and sexuality. ...
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Background We are witnessing renewed debates regarding definitions and boundaries of human gender/sex, where lines of genetics, gonadal hormones, and secondary sex characteristics are drawn to defend strict binary categorizations, with attendant implications for the acceptability and limits of gender identity and diversity. Aims Many argue for the need to recognize the entanglement of gender/sex in humans and the myriad ways that gender experience becomes biology; translating this theory into practice in human biology research is essential. Biological anthropology is well poised to contribute to these societal conversations and debates. To do this effectively, a reconsideration of our own conceptions of gender/sex, gender identity, and sexuality is necessary. Methods In this article, we discuss biological variation associated with gender/sex and propose ways forward to ensure we are engaging with gender/sex diversity. We base our analysis in the concept of “biological normalcy,” which allows consideration of the relationships between statistical distributions and normative views. We address the problematic reliance on binary categories, the utilization of group means to represent typical biologies, and document ways in which binary norms reinforce stigma and inequality regarding gender/sex, gender identity, and sexuality. Discussion and Conclusions We conclude with guidelines and methodological suggestions for how to engage gender/sex and gender identity in research. Our goal is to contribute a framework that all human biologists can use, not just those who work with gender or sexually diverse populations. We hope that in bringing this perspective to bear in human biology, which novel ideas and applications will emerge from within our own discipline.
... In early childhood, sharing a bed with others during sleep, referred to as bedsharing, is a globally widespread, yet controversial practice (McKenna, Ball, & Gettler, 2007;Mileva-Seitz, Bakermans-Kranenburg, Battaini, & Luijk, 2017). Despite the ubiquity of bedsharing (Mileva-Seitz et al., 2017), debate regarding the impact of bedsharing on children's sleep and development continues to exist, particularly in the United States (Ball, 2006a(Ball, , 2006bOwens, 2004). ...
Article
Bedsharing (sharing a bed with others during sleep) in early childhood (3–5 years old) is common across Western and non-Western societies alike. Though prior work indicates that bedsharing may relate to impairments in child sleep quantity or quality, the majority of studies conducted in young children are limited to parent-child bedsharing and rely almost exclusively on caregiver reports to measure child sleep. Here, the authors endeavored to gain further insights into the diversity of bedsharing practices among children in the United States, including how different bedsharing partners (caregivers, siblings) might impact actigraphy-derived measures of children’s sleep. Using a sample of 631 children ages 2:9 to 5:11 years, we found that over 36% of children bedshared in some form overnight, with approximately 22% bedsharing habitually. In a subset of children for whom actigraphy measures were collected (n = 337), children who bedshared habitually (n = 80) had significantly shorter overnight sleep, later sleep and wake times, and longer naps than solitary sleepers (n = 257), even when controlling for socioeconomic status. Despite supplementing their shorter overnight sleep with longer naps, habitually bedsharing children had significantly shorter 24-hr sleep time than did solitary sleepers, though differences in sleep efficiency were nonsignificant for all sleep periods. Additionally, sleep efficiency, onset latency, and duration did not differ between children who habitually bedshared with siblings versus those who habitually bedshared with parents. The present results add to prior work examining family contextual correlates of sleep differences in early childhood and provide a more objective account of relations between bedsharing and child sleep.
... In WEIRD societies models of infant care became biomedicalized as a consequence of the reliance on statistical normalcy, that is, conceptualized as within the purview of medical experts who set the standards for what is considered "normal" and "healthy" sleep (Ball, 2008;Ball et al., 2019;McKenna et al., 2007;Tomori, 2014). Biological and evolutionary views on infant sleep norms entered the discourse only over the past 20 years, but are now beginning to gain traction with both parents and health practitioners, and with a small but growing group of pediatricians and infant sleep researchers (e.g., Barry, 2020;Mileva-Seitz et al., 2017). ...
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Objectives We examine infant sleep from evolutionary, historico‐cultural, and statistical/epidemiological perspectives and explore the distinct conceptions of “normal” produced by each. We use data from the “Sleeping Like a Baby” study to illustrate how these perspectives influence the ideals and practices of new parents. Methods The “Sleeping Like a Baby” study investigated maternal–infant sleep in north‐east England. Sleep data for exclusively breastfeeding (EBF) and formula‐feeding (EFF) dyads were captured every 2 weeks from 4 to 18 weeks postpartum through actigraphy and maternal report. Mothers also reported their infant sleep ideals and practices. Results explore objective and maternally‐reported infant sleep parameters, and concordance of maternal ideals and practices with public health guidance. Results Comparison of sleep measures showed that mothers overestimate infant sleep duration compared with actigraphy; EFF mothers' reports were significantly more inaccurate than those of EBF mothers. For infants moved to a separate bedroom, maternally‐reported sleep increases were not borne out by actigraphy. Across the study period, concordance of maternal ideal sleep location with public health recommendations occurred on average for 54% of mothers, while concordance in practice fell from 75% at 4–8 weeks to 67% at 14–18 weeks. Discordance for EBF dyads occurred due to bedsharing, and for EFF dyads due to infants sleeping in a room alone. Conclusions Beliefs about “normal” infant sleep influence parents' perceptions and practices. Clinical and scientific infant sleep discourses reinforce dominant societal norms and perpetuate these beliefs, but biological and evolutionary views on infant sleep norms are beginning to gain traction with parents and health practitioners.
... However, studies of human biological variation have largely ignored an incredibly important aspect of human biology: human milk. Some of this may reflect cultural biases-in Western societies that have produced much of anthropological thought in the last five decades, commercial infant formula, not breastfeeding, has been the predominant form of infant feeding (McKenna et al., 2007;Palmer, 2009;Tomori et al., 2018). There has also been a generalized belief that human milk does not vary in composition (Hall, 1979), despite considerable evidence to the contrary (Prentice, 1995). ...
Article
Objectives Human biological variation in the phenotype is the cornerstone of modern human biology, evolutionary anthropology, and related studies of human evolution. Minimal dialogue, however, has considered human milk to be part of this phenotypic variation. This may reflect researcher bias‐mental models oriented around commercial infant formula and homogenized cow's milk, both of which present milk composition as static. A general lack of research outside primarily Western, well‐nourished populations has also contributed to this underestimation of biological variation. Methods This review analyzes published research on breast milk composition, developmental metabolic programming, and maternal body composition to articulate the ways in which population‐based studies of human milk outside the United Sates are necessary to better understanding biological variation in human milk phenotypes. Results This review discusses some of the common issues in current research on the biological variation in human milk composition and argues that anthropological inquiries that frame milk as part of an adaptive phenotype are necessary to better understand the biological significance of human milk composition in the production of human biological variation. Conclusions Biological anthropology is uniquely positioned to investigate biological variation in human milk, using evolutionary theory, cutting edge biology, and anthropologically informed perspectives that challenge the biomedical framing of lactation and often act to privilege well nourished, primarily western populations and formula feeding as normatives for infant feeding research.
... There is evidence that infants may benefit from sleeping in close proximity to their mother, and that not having the positive physiological regulatory effects from the mother may actually increase the risk of Sudden Infant Death Syndrome. 51 For example, Basque social theories support the notion that bed sharing facilitates healthy personality development. 52 Broadly, by this theory, bed sharing is seen as appropriate for familial bonding. ...
Article
Background Bed sharing is common practice across the global population. However, the vast majority of research on bed sharing has focused solely on mother-infant bed sharing. Methods Here, we provide a holistic review of research on bed sharing. Articles investigating the relationship between bed sharing and sleep were identified in 4 dyad categories: (1) parent and child, (2) couples, (3) siblings, and (4) pet owners and pets. Of interest was whether sleep-promoting factors such as psychological comfort were generalizable across bed-sharing dyads; alternatively, sleep-demoting factors such as movement or heat may be commonalities. Results We found that, across dyad types, in general, subjective reports of sleep quality were better when bed sharing despite generally worse objective measures of sleep. Conclusions Understanding bed sharing is important to treating sleep disturbances, given the prevalence of shared beds. This scoping review points to critical gaps in our understanding of bed sharing that motivate future research.
... With regard to room-sharing, the American Academy of Pediatrics (AAP) recommends that children should sleep within the same room as the parents (in a separate cot) during the first 6 months after birth [39], as parent-infant room sharing is associated with reduced rates of Sudden Infant Death Syndrome (SIDS e.g., [40,41]). Also, the availability of the parents seems to help buffering the infant's distress [42,43], and facilitates the breastfeeding process [44][45][46]. This RCT will thus also examine the effectiveness of the universal prevention program to increase parental caregiving quality (i.e. ...
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Background The first months postpartum can be challenging for parents, leading to elevated symptoms of parenting stress, depression and anxiety. In turn, distressed parents are at higher risk for providing suboptimal quality of caregiving. As psychoeducational interventions can be effective in reducing psychological distress, the goal of this randomized controlled trial was to examine the effectiveness of low-intensity universal psychoeducational program to prevent postpartum parenting stress, and to enhance parental well-being and caregiving quality. Method Between 26 and 34 weeks of pregnancy, 138 pregnant women and 96 partners were randomized to the intervention or a waitlist control group. The intervention consisted of a booklet, a video, a home visit, and a telephone call. Information was provided on (1) sensitive responsiveness, adapting to the parental role, and attending to own needs; (2) crying patterns; (3) feeding (arrangements); and (4) sleeping (arrangements). The primary outcome was parenting stress postpartum. Secondary outcomes were additional measures of distress (depression and anxiety), parental well-being, and caregiving quality. Results Both groups showed a rise in distress after birth. No between-group differences were observed on parenting stress, nor on the secondary outcomes. The intervention was rated as useful and of added value by the parents. Conclusion This study offered no evidence that our universal prevention program was effective in decreasing parental distress or in increasing caregiving quality. However, parents found aspects of the intervention useful. More research is needed, including a longer period of follow-up as well as observational measures of parents’ responsiveness. Trial registration This trial has been registered on 15 September 2016 in the Netherlands National Trial Register, ID: NTR6065, https://www.trialregister.nl/trial/5782.
... The construct of breastsleeping offers a way to examine the above findings in an evolutionary and biological manner. The comparative ethnographic examples above align with biological anthropological research that has documented the strong physiological relationship between breastfeeding and bedsharing and emphasize the importance of considering the integrated, adaptive characteristics of these behaviors (McKenna, Ball, and Gettler 2007, McKenna and Gettler 2016, Ball 2017. Despite western concerns about the dangers of bedsharing, large epidemiological studies have also noted the relationship between breastfeeding and bedsharing. ...
... Co-sleeping is commonly defined as a child sleeping in close proximity to the parent(s), whether on the same sleep surface (bedsharing) or in the same room on a separate sleep surface (room-sharing;McKenna, Ball, & Gettler, 2007). Parents in the United States report co-sleeping with their infants for reasons such as preference and to facilitate sleep (Tully, Holditch-Davis, & Brandon, 2015), housing/financial circumstances (e.g., space limitations, inability to purchase a crib), and infant care and breastfeeding convenience (Ball, 2002). ...
Article
Parents in the United States increasingly report bed-sharing with their infants (i.e., sleeping on a shared sleep surface), but the relationship between bed-sharing and child socioemotional outcomes are not well understood. The current study examines the links between mother-infant bed-sharing at 3 months and infant affect and behavior during a dyadic challenge task at 6 months. Further, we examine nighttime mother-infant contact at 3 months as a possible mechanism that may mediate linkages between bed-sharing and infant outcomes. Using observational data from a sample of 63 mother-infant dyads, we found that infants who bed-shared for any proportion of the observation period at 3 months displayed significantly more self-regulatory behaviors during the still-face episode of the Still-Face Paradigm (SFP) at 6 months, compared to non-bed-sharing infants. Also, infants of mothers who bed-shared for the entire observation period displayed significantly less negativity during the reunion episode than non-bed-sharing infants. There was no evidence that the relations between mother-infant bed-sharing practices and infant affect and behavior during the SFP were mediated through nighttime mother-infant contact. Results suggest that infant regulation at 6 months postpartum may vary based on early nighttime experiences, with bed-sharing potentially promoting more positive and well-regulated behavior during dyadic interaction.
... These practices emphasize distal communications and early physical separation in the purported pursuit of safety and a healthy individuation process. Such practices stand in contract to proximity-oriented Eastern/ Southern/indigenous practices, which embrace extended contact and infant-led separation (Keller, Borke, Lamm, Lohaus, & Dzeaye Yovsi, 2011;Graham, Manara, Chokotho, & Harrison, 2015;Hewlett, Lamb, Shannon, Leyendecker, & Schölmerich, 1998;Keller et al., 2009;Liedloff, 1986;Lozoff & Brittenham, 1979;McKenna, Ball, & Gettler, 2007;St James-Roberts et al., 2006). For a review of mother-infant contact within nocturnal caregiving practices, please see Barry (2019). ...
Article
During the early period of hypothesis building and empirical testing of attachment theory, a major emphasis was placed on mother-infant physical contact. In spite of this, mother-infant contact has received scant attention amongst attachment and child development researchers in the past decades. Here, a brief theoretical framework for mother-infant contact is presented, drawing on animal studies as well as human studies of preterm infants and neonates. Salient mechanisms may include an extended sensitive period during early infancy, requiring specific somatosensory stimuli for bio-behavioral homeorhesis; oxytocinergic and epigenetic pathways; kinesthetic stimuli and face-to-face proximity allowing for increased social interaction. Studies of extended human mother-full-term infant physical contact have demonstrated positive effects in multiple domains. For infants, these include sleep organization, temperature and heart rate regulation, behavioral response, crying/colic, socio-emotional development, attachment quality, speech development opportunities and mother-child interactions. For mothers, studies demonstrate improved depressive symptomatology, physiological stress regulation, contingent responsivity, breastfeeding and mother-child interactions. Parent-infant attachment quality has gained prominence as a trauma-resilience factor as well as a predictor of adult physical health. The potential role of mother-infant contact as an attachment promoting intervention as well as future research subjects are discussed. Current evidence supports the original attachment research that early maternal touch provision may influence infant socio-emotional development and attachment quality, with positive implications for mother-child relationship functioning.
... These practices emphasize distal communications and early physical separation in the purported pursuit of safety and a healthy individuation process. Such practices stand in contract to proximity-oriented Eastern/ Southern/indigenous practices, which embrace extended contact and infant-led separation (Keller, Borke, Lamm, Lohaus, & Dzeaye Yovsi, 2011;Graham, Manara, Chokotho, & Harrison, 2015;Hewlett, Lamb, Shannon, Leyendecker, & Schölmerich, 1998;Keller et al., 2009;Liedloff, 1986;Lozoff & Brittenham, 1979;McKenna, Ball, & Gettler, 2007;St James-Roberts et al., 2006). For a review of mother-infant contact within nocturnal caregiving practices, please see Barry (2019). ...
Article
We propose that infant carrying is a biological norm for human caregiving, given that human infants have evolved a capacity to cling onto an upright caregiver whose body co-evolved to enable offspring carrying. The origins of this mutual adaptation may date back 4 million years, with the emergence of bipedalism, which precluded the infant horizontal and gravity-supported position on the back of a quadrupedal caregiver. We describe infant cooperative reflexes and behaviors, including the carrying-induced calming response and discuss hypotheses for the invention of infant carrier tools. Carrying involves several physiological and behavioral parent-infant co-adaptations that imply it is an evolutionarily conserved strategy. Epigenetic transmission of reproductive behavior through generations affects the development of the offspring, as well as the mental health of the parent. Carrying might have contributed to the evolution of Hominidae, potentially aiding dexterity, handedness, language acquisition, and social interactions. We review the evolutionary milestones and time points where the infant-caregiver interactions might have changed, exploring infant carrying as it intersects with biological and cultural evolution. We briefly summarize the effects of infant carrying on physiological, epigenetic, and socio-emotional outcomes.
... 1,8 Parentinfant bedsharing with breastfeeding constitutes the human evolutionary norm as demonstrated in anthropological research. [63][64][65][66][67] In industrialized countries until the early 20th century, most infants were bedsharing and breastfeeding. 68 After that time, solitary sleep developed as an ideal among the middle classes, reinforced by the growing trends of artificial feeding and medicalization of childbirth, separating infants from mothers. ...
Article
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A central goal of the Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient.
Article
A systematic review of qualitative studies was conducted to explore how parents perceive sleep quality in their infants aged 0–24 months and the factors that influence these perceptions. A systematic search of the databases Scopus, Embase, Cinahl, PsycInfo and MEDLINE, was undertaken to identify eligible peer‐reviewed studies published between 2006–2021. Ten papers met inclusion criteria and were subsequently included in the review. Evaluation of papers with the Critical Appraisal Skills Programme qualitative checklist classified papers as weak, moderate or strong, with half considered strong. Thematic synthesis identified one superordinate theme, culture, and five interrelated subordinate themes regarding how parents perceive their infant's sleep and the factors that may influence these perceptions. These themes were: (1) Infants physical and emotional comfort; (2) Beliefs regarding safety; (3) Parental and familial wellbeing; (4) Perceived degree of infant agency; (5) Influence of external beliefs and opinions. The findings from this review may assist practitioners in providing parents with personalized and culturally sensitive information regarding infant sleep and may also inform antenatal and early intervention practices, subsequently minimizing parental distress regarding infant sleep patterns.
Article
Every year in the United States, approimately 3500 infants die of sleep-related infant deaths, including sudden infant death syndrome (SIDS) (International Statistical Classification of Diseases and Related Health Problems 10th Revision [ICD-10] R95), ill-defined deaths (ICD-10 R99), and accidental suffocation and strangulation in bed (ICD-10 W75). After a substantial decline in sleep-related deaths in the 1990s, the overall death rate attributable to sleep-related infant deaths have remained stagnant since 2000, and disparities persist. The triple risk model proposes that SIDS occurs when an infant with intrinsic vulnerability (often manifested by impaired arousal, cardiorespiratory, and/or autonomic responses) undergoes an exogenous trigger event (eg, exposure to an unsafe sleeping environment) during a critical developmental period. The American Academy of Pediatrics recommends a safe sleep environment to reduce the risk of all sleep-related deaths. This includes supine positioning; use of a firm, noninclined sleep surface; room sharing without bed sharing; and avoidance of soft bedding and overheating. Additional recommendations for SIDS risk reduction include human milk feeding; avoidance of exposure to nicotine, alcohol, marijuana, opioids, and illicit drugs; routine immunization; and use of a pacifier. New recommendations are presented regarding noninclined sleep surfaces, short-term emergency sleep locations, use of cardboard boxes as a sleep location, bed sharing, substance use, home cardiorespiratory monitors, and tummy time. In addition, additional information to assist parents, physicians, and nonphysician clinicians in assessing the risk of specific bed-sharing situations is included. The recommendations and strength of evidence for each recommendation are published in the accompanying policy statement, which is included in this issue.
Article
Human infants spend most of their time sleeping, but over the first few years of life their sleep becomes regulated to coincide more closely with adult sleep (Galland et al., 2012; Paavonen et al., 2020). Evidence shows that co-sleeping played a role in the evolution of infant sleep regulation, as it is part of an ancient behavioral complex representing the biopsychosocial microenvironment in which human infants co-evolved with their mothers through millions of years of human history (Ball, 2003; McKenna 1986, 1990). This paper is a conceptual, interdisciplinary, integration of the literature on mother-infant co-sleeping and other mother-infant co-regulatory processes from an evolutionary (biological) perspective, using complexity science. Viewing the mother-infant dyad as a “complex adaptive system” (CAS) shows how the CAS fits assumptions of regulatory processes and reveals the role of the CAS in the ontogeny of mother-infant co-regulation of physiological (thermoregulation, breathing, circadian rhythm coordination, nighttime synchrony, and heart rate variability) and socioemotional (attachment and cortisol activity) development.
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Background and Objectives Heat stress and hyperthermia are common findings in sudden infant death syndrome (SIDS) victims. It has been suggested that thermal stress can increase the risk of SIDS directly via lethal hyperthermia or indirectly by altering autonomic functions. Major changes in sleep, thermoregulation, cardiovascular function, and the emergence of circadian functions occur at the age at which the risk of SIDS peaks—explaining the greater vulnerability at this stage of development. Here, we review the literature data on (i) heat stress and hyperthermia as direct risk factors for SIDS, and (ii) the indirect effects of thermal loads on vital physiological functions. Results Various situations leading to thermal stress (i.e., outdoors temperatures, thermal insulation from clothing and bedding, the prone position, bed-sharing, and head covering) have been analyzed. Hyperthermia mainly results from excessive clothing and bedding insulation with regard to the ambient thermal conditions. The appropriate amount of clothing and bedding thermal insulation for homeothermia requires further research. The prone position and bed-sharing do not have major thermal impacts; the elevated risk of SIDS in these situations cannot be explained solely by thermal factors. Special attention should be given to brain overheating because of the head's major role in body heat losses, heat production, and autonomic functions. Thermal stress can alter cardiovascular and respiratory functions, which in turn can lead to life-threatening events (e.g., bradycardia, apnea with blood desaturation, and glottal closure). Unfortunately, thermal load impairs the responses to these challenges by reducing chemosensitivity, arousability, and autoresuscitation. As a result, thermal load (even when not lethal directly) can interact detrimentally with vital physiological functions. Conclusions With the exception of excessive thermal insulation (which can lead to lethal hyperthermia), the major risk factors for SIDS appears to be associated with impairments of vital physiological functions when the infant is exposed to thermal stress.
Chapter
Child well-being is an indispensable and often a complex part of most parents’ daily concerns. In addition to the parenting styles and social interactions inside or outside one’s primary environment, urbanized living and contemporary lifestyle habits have brought into focus the attitudes and behaviors displayed by parents or caregivers with subtle to pronounced impact on children sharing the same household. As we transition through these changes, a shift in focus from mere survival to physical and psychological well-being is imperative. Driven by the complexities of the new-age social and economic trends, the chapter illustrates a socio-ecological approach to assay the transactional individual orientations, life choices, and community-based indicators of child health. Agents of consumerism showcase conspicuous consumer socialization and materialism, including dietary habits and brand imaging which impinges upon child health, identity, and self-esteem. Parents’ work–life choices and an apparent insufficiency of resources to cope with the work–life conflict, stress, and burnout, create an unhealthy environment for the children where they can be exposed to adult behaviors ranging from substance abuse to violence. Finally, lifestyle choices including sedentary living, poor sleep hygiene, and a surge in screen time and digital dependence are leaving an indelible mark on the child’s own life choices and future health. We purport to unravel the modern connotations of child empowerment and autonomy alongside their diverse child well-being outcomes in our pursuit of desirable nurturing.
Article
The study examines the association between infant sleep, physiological, and emotional reactivity at 3 and 6 months of age in 89 African American infants and their caregivers. Infant sleep was objectively measured at 3 and 6months using actigraphy for 7 days and nights. At 6 months of age, dyads participated in the Still-Face Paradigm (SFP) (Tronick et al., 1978) to assess infants’ physiological reactivity (via respiratory sinus arrhythmia (RSA)) and emotional reactivity. Findings revealed that infant night wakings at 3 months was positively correlated with baseline RSA at 6 months (β = .35, p < .001). Night wakings at 3 months marginally predicted negative affect during the recovery episode of SFP (β = −.26, p = .057). Further, night wakings at 6-months-old predicted more positive affect during the recovery episode of SFP (β = .34, p = .007). We discuss potential explanations for these findings such as an exuberant temperament style, parenting behavior, and lack of sleep consolidation at this early age to be the focus of future studies in this area. The current study adds to the limited research examining the relationship between sleep and reactivity in the earliest months of development. Findings reveal that it is critical to take developmental timing into account as all results were unexpected in relation to the childhood literature. Moreover, this is the first study of its kind to focus on an African American sample.
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This paper comprises a collection of illustrations, along with background information, analysis, and commentary, from “baby books”—advice books published in the United States for a parent audience from the 1890s to the 1980s. These publications, and especially their drawings and photos, provide a window on past child rearing practices and beliefs. The paper provides historical background on parenting behaviors such as toilet training and infant feeding, then traces changes over time through drawings and photos that appeared in parenting advice publications. These publications grew in popularity as changing work and family structures removed traditional sources of information for parents, and scientific information and expert guidance took their place. Publications from a variety of sources, but especially the U.S. Children’s Bureau, are explored. A finding of note is that images of babies and their families, which in earlier publications were entirely white and middle class, became more diverse over time. The author concludes that published parental advice from professionals made for a fascinating study, was ideologically driven, and often lacked a basis in empirical scientific knowledge of child development, and therefore asserts that parents may regard such advice conditionally.
Article
Bedsharing is controversial for nighttime caregiving in the U.S. today, as in most of the West. However, from the standpoint of evolutionary pediatrics, anthropology, and cultural psychology, bedsharing is not controversial at all, representing the context for human infant evolution and conferring a host of physiological benefits to the infant as well as the mother. In an effort to understand the rise in Western bedsharing in recent decades (and following Ball, 2002; McKenna & Volpe, 2007), Salm Ward (2015) systematically reviewed the literature on mother-infant bedsharing and identified ten reasons why mothers choose to bedshare: (1) breastfeeding, (2) comforting for mother or infant, (3) better/more sleep for infant or parent, (4) monitoring, (5) bonding/ attachment, (6) environmental reasons, (7) crying, (8) cultural or familial traditions, (9) disagree with danger, and (10) maternal instinct. The current paper offers the “review behind the review,” highlighting the scientific evidence behind the reasons mothers give for their decision to bedshare, focusing on how mothers’ decisions about infant sleep location influence infant behavior and development.
Article
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Humans have a prolonged childhood, which begins with an immature developmental state at birth. We take care of these helpless infants through a variety of cultural adaptations, including material culture, provisioning of food, and shared child care. Our species has long been characterized as having secondary altriciality, but an examination of human life history shows that we are fundamentally precocial, despite seeming helpless at birth. Human babies are also relatively large and overall require substantial attention and energy from caregivers. Previous work has focused on how culture permits us to give birth to helpless young and how our cultural adaptation solves problems stemming from encephalization. The birth of these dependent, costly creatures poses challenges but also creates opportunities by enhancing the development of social and emotional relationships with caregivers as well as language acquisition and enculturation.
Article
Introduction : Sleeping with your infant (known as co-sleeping) is a proximal parenting practice. In some societies, 80 percent of children sleep with their parents. In France, a culture of sleeping separately has emerged, and the practice of co-sleeping has been associated with sudden infant death syndrome (SIDS). International recommendations tend to advise against co-sleeping and to devalue it as a practice.Material and methods : Two focus groups with co-sleepers (n=6) complemented by ten in-depth interviews were organized to identify the motivations and organization that mothers and their partners have when it comes to practicing co-sleeping with their children. A content analysis of what was said in the interviews by individuals and couples enabled us to find out more about the needs that co-sleeping responds to, as well as parents' co-sleeping practices.Results : Co-sleeping, made taboo by SIDS, responds to emotional and practical factors. The couple's life does not seem to be negatively impacted by it. The positive relationship it allows parents to have with their children is valued. Recommendations may often describe this way of sleeping as "unsafe," but co-sleepers support this parenting practice, along with breastfeeding.Conclusion : The results highlight the health education importance for co-sleepers. Being educated about co-sleeping will ensure that their practice is safe and will mean that they do not isolate themselves socially to hide it because they only have partial knowledge of the SIDS safety measures.
Article
An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of how fetal monitoring may lead to overuse of birth-related interventions, commentaries on reviews focused on bedsharing, and women’s lifetime estrogen exposure and risk of cardiovascular mortality.
Article
Background: There is great global variation in the sleeping arrangements for healthy newborn infants. Bed sharing is a type of sleeping practice in which the sleeping surface (e.g. bed, couch or armchair, or some other sleeping surface) is shared between the infant and another person. The possible physiological benefits include better oxygen and cardiopulmonary stability, fewer crying episodes, less risk of hypothermia, and a longer duration of breastfeeding. On the other hand, the most important harmful effect of bed sharing is that it may increase the risk of sudden infant death syndrome (SIDS). Studies have found conflicting evidence regarding the safety and efficacy of bed sharing during infancy. Objectives: To evaluate the efficacy and safety of bed sharing, started during the neonatal period, on breastfeeding status (exclusive and total duration of breastfeeding), incidence of SIDS, rates of hypothermia, neonatal and infant mortality, and long-term neurodevelopmental outcomes. Search methods: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2020, Issue 7) in the Cochrane Library; MEDLINE via PubMed (1966 to 23 July 2020), CINAHL (1982 to 23 July 2020), and LILACS (1980 to 23 July 2020). We also searched clinical trials databases, and the reference lists of retrieved articles, for randomised controlled trials (RCTs) and quasi-RCTS. Selection criteria: We planned to include RCTs or quasi-RCTs (including cluster-randomised trials) that included term neonates initiated on bed sharing within 24 hours of birth (and continuing to bed share with the mother in the first four weeks of life, followed by a variable time period thereafter), and compared them to a 'no bed sharing' group. Data collection and analysis: We used standard methodological procedures as recommended by Cochrane. We planned to use the GRADE approach to assess the certainty of evidence. Main results: Our search strategy yielded 6231 records. After removal of duplicate records, we screened 2745 records by title and abstract. We excluded 2739 records that did not match our inclusion criteria. We obtained six full-text studies for assessment. These six studies did not meet the eligibility criteria and were excluded. Authors' conclusions: We did not find any studies that met our inclusion criteria. There is a need for RCTs on bed sharing in healthy term neonates that directly assess efficacy (i.e. studies in a controlled setting, like hospital) or effectiveness (i.e. studies conducted in community or home settings) and safety. Future studies should assess outcomes such as breastfeeding status and risk of SIDS. They should also include neonates from high-income countries and low- and middle-income countries, especially those countries where bed sharing is more prevalent because of cultural practices (e.g. Asian countries).
Article
Infants evolved in the context of close contact (including co-sleeping). Evolutionary context is rarely considered in psychological infant sleep research, and Western sleep researchers make assumptions about what optimal “normal” infant sleep is and how to achieve early, deep, infant sleep consolidation and avoid infant sleep problems. However, an evolutionary and anthropological view of infant sleep as species-typical recognizes that human evolution likely prepared the infant brain for optimal development within its evolutionary context – co-sleeping. Thus, “normal” infant sleep, sleep consolidation, and sleep problems should all be understood within the framework of co-sleeping infants, not the historically new-phenomenon of solitary-sleeping infants. Much work needs to be done in order to understand “normal” infant sleep as species-typical and how adaptive infants are to environments that stray from their evolutionary norm.
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The purpose of the present study is to examine the association between toddlers' sleep arrangements and their nighttime sleep duration and other sleep variables. For this investigation, we performed a study in which child activity and sleep levels were recorded using actigraphy. The parents of 1.5-year-old toddlers (n = 106) were asked to attach an actigraphy unit to their child’s waist with an adjustable elastic belt and complete a sleep diary for 7 consecutive days. Questionnaires were used to assess the sleep arrangements of the toddlers. There was a significant negative correlation between nap duration and nighttime sleep duration, suggesting that longer nap sleep induces shorter nighttime sleep duration. Among the sleep arrangements, such as nighttime breastfeeding or co-sleeping, only nighttime breastfeeding predicted shorter nighttime sleep duration. Our findings indicate that shorter naps induce a longer nighttime sleep in 1.5-year-old toddlers while nighttime breastfeeding decreases their nighttime sleep duration.
Chapter
This chapter outlines the importance of sleep in children, which is a necessary daily activity for optimal functioning. It will examine the research related to the specific role of sleep in a child’s development and well-being, as well as the biological and environmental factors which regulate sleep. It will finally also examine how sleep problems can be defined, as well as the impact on the child and their families if they experience inadequate sleep.
Article
The American Academy of Pediatrics recommends against bed-sharing between infants and caregivers due to an association with suffocation. Caregivers continue to share a bed with their infant despite these recommendations for a multitude of reasons. A close examination of the bed-sharing literature reveals that the debate is fundamentally about theoretical differences. The major theories used to frame this problem include the triple risk model of bed-sharing and evolutionary theories. Nurses are masters of multidisciplinary collaboration and are well positioned to unify the triple risk and evolutionary views of infant bed-sharing to guide future innovations in health care practice and research.
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Room-sharing without bed-sharing is perhaps the most controversial of the safe infant sleep recommendations, with many parents and clinicians alike resisting adherence. This chapter describes the controversies associated with the recommendation, the evidence base for the recommendation, and advice to clinicians about how to counsel parents, with attention to the potential barriers and suggestions about how to overcome them.
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The human need for sleep is universal and unquestioned; however, humans vary in their sleep needs according to age, individual differences, as well as cultural and social norms and practices. Therefore, what is “normal” in infant sleep and the development of sleep architecture in humans is highly dependent on biological and sociocultural variables as well as socially constructed assumptions about what infant sleep “should” look like. This paper uses a multidisciplinary approach to review papers from fields including pediatrics, anthropology, psychology, medicine, and sociology to understand “normal” infant sleep. Because human culture and behavioral practice changes much more quickly than evolved human biology, and because human evolutionary history occurred in the context of breastfeeding and cosleeping, new work in the field of infant sleep architecture development would benefit from a multidisciplinary approach. To come to a consensus about what is “normal” infant sleep, researchers must agree on underlying basic assumptions of infant sleep from which to ask question and interpret findings.
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Abstract This study investigates the attitude of mothers towards the phenomenon of cosleeping, based on Super and Harkens’s Developmental Niche Theory. Semistructured interviews were administered with 13 mothers of at least one 3 to 6 year-old child, in two groups of cosleepers and separate sleepers. Qualitative and phenomenological approach and Colaizzi analysis method was used. Data were categorized based on the subsystems of Niche theory. In sociophysical
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In families with infants between the ages of 6 and 18 months, sleep disruption can be significant, often putting parents at risk of a range of negative psychological and psychosocial consequences. Commonly prescribed sleep interventions typically involve ‘extinction’ methods, which require parents to completely or periodically ignore their infant's overnight cries. These methods can be effective in many, but not all cases. For over 40 years 30–40% of parents have consistently reported difficulty ignoring their child. For this group, ignoring their child is behaviourally and/or ideologically difficult with attrition often leading to a perceived sense of failure. For these parents the treatment may be worse than the problem. On the other hand, there is emerging evidence to support the use of more responsive methods for those who find extinction approaches behaviourally or ideologically challenging. In this paper we propose an integrated, less polarised approach to infant behavioural sleep interventions that better caters to those who have difficulty with extinction methods – our so‐called ‘Plan B’. This approach potentially resolves the often opposing ideological and theoretical perspectives of extinction versus responsiveness into a practical, complementary and pragmatic treatment framework. Recommendations on how best to implement Plan B are also presented. In our view, Plan B could provide practitioners with a logically integrated well‐targeted suite of clinical interventions that could potentially improve compliance, reduce attrition and ultimately benefit the sleep and well‐being of all infants and their parents, especially those who struggle with traditional extinction methodologies.
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The objective of the study was to investigate habitual nightly sleep patterns in the context of daily accounts of relationships with bed partners utilizing the attachment theory framework. Negative exchanges with a spouse are stressful and presumably activate the attachment system. This will differently affect individuals with high and low levels of attachment avoidance and anxiety orientations, affecting their sleep patterns. Seventy-seven teachers in committed romantic relationships (mean age = 42.53 years, 89.3% married) participated. They first completed the Experience in Close Relationships–Revised instrument, indicating their attachment avoidance and anxiety orientations, and then participated in a 4-day diary study, reporting daily levels of negative exchanges with a spouse. They also wore an actigraph (activity monitor) during the nighttime to assess their sleep patterns. Mixed-model analyses revealed that respondents high in attachment avoidance had later bedtimes and shorter sleep duration following days high in negative behavioral exchanges with their spouses. In addition, respondents high in attachment avoidance had longer sleep latency and more waking episodes during the night, regardless of levels of negative exchanges. Individuals high in attachment anxiety had more waking episodes during the night after negative emotional exchanges with a spouse; the opposite pattern emerged for individuals low in attachment anxiety. Findings demonstrate the relevance of attachment orientations and the moderating effects of negative exchanges with a spouse on sleep patterns.
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Sleep is a complex physiological process that is regulated globally, regionally, and locally by both cellular and molecular mechanisms. It occurs to some extent in all animals, although sleep expression in lower animals may be co-extensive with rest. Sleep regulation plays an intrinsic part in many behavioral and physiological functions. Currently, all researchers agree there is no single physiological role sleep serves. Nevertheless, it is quite evident that sleep is essential for many vital functions including development, energy conservation, brain waste clearance, modulation of immune responses, cognition, performance, vigilance, disease, and psychological state. This review details the physiological processes involved in sleep regulation and the possible functions that sleep may serve. This description of the brain circuitry, cell types, and molecules involved in sleep regulation is intended to further the reader’s understanding of the functions of sleep.
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Background: Although childbearing is known to protect against breast cancer, whether or not breastfeeding contributes to this protective effect is unclear. Methods: Individual data from 47 epidemiological studies in 30 countries that included information on breastfeeding patterns and other aspects of childbearing were collected, checked, and analysed centrally, for 50302 women with invasive breast cancer and 96973 controls. Estimates of the relative risk for breast cancer associated with breastfeeding in parous women were obtained after stratification by fine divisions of age, parity, and women's ages when their first child was born, as well as by study and menopausal status. Findings: Women with breast cancer had, on average, fewer births than did controls (2.2 vs 2.6). Furthermore, fewer parous women with cancer than parous controls had ever breastfed (71% vs 79%), and their average lifetime duration of breastfeeding was shorter (9.8 vs 15.6 months). The relative risk of breast cancer decreased by 4.3% (95% CI 2.9-5.8; p<0.0001) for every 12 months of breastfeeding in addition to a decrease of 7.0% (5.0-9.0; p<0.0001) for each birth. The size of the decline in the relative risk of breast cancer associated with breastfeeding did not differ significantly for women in developed and developing countries, and did not vary significantly by age, menopausal status, ethnic origin, the number of births a woman had, her age when her first child was born, or any of nine other personal characteristics examined. It is estimated that the cumulative incidence of breast cancer in developed countries would be reduced by more than half, from 6.3 to 2.7 per 100 women by age 70, if women had the average number of births and lifetime duration of breastfeeding that had been prevalent in developing countries until recently. Breastfeeding could account for almost two-thirds of this estimated reduction in breast cancer incidence. Interpretation: The longer women breast feed the more they are protected against breast cancer. The lack of or short lifetime duration of breastfeeding typical of women in developed countries makes a major contribution to the high incidence of breast cancer in these countries.
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There is a growing concern in relation to the problem of insufficient sleep, particularly in the United States. In the early 1990s a Congressionally mandated commission noted that insufficient sleep is a major contributor to catastrophic events, such as Chernobyl and the Exxon Valdez, as well as personal tragedies, such as automobile accidents. Adolescents appear to be among the most sleep-deprived populations in our society, though they are rarely included in sleep assessments. This book explores the genesis and development of sleep patterns in adolenscents. It examines biological and cultural factors that influence sleep patterns, presents risks associated with lack of sleep, and reveals the effects of environmental factors such as work and school schedules on sleep. Originally published in 2002, Adolescent Sleep Patterns will appeal to psychologists and sociologists of adolescence who have not yet considered the important role of sleep in the lives of our youth.
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Two groups of infants, 2 and 9 months of age, were monitored for one night by time-lapse videotape recording in the natural setting of their homes. Developmental changes in sleep-wake state proportions, ease of falling asleep, nighttime waking patterns, maternal interventions, and sleeping through the night were observed. A suggestion of differential parental handling of male infants was noted. Further research to clarify some of these issues is indicated.
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The evolution and origin of primate social organisation has attracted the attention of many researchers, and a solitary pattern, believed to be present in most nocturnal prosimians, has been generally considered as the most primitive system. Nocturnal prosimians are in fact mostly seen alone during their nightly activities and therefore termed 'solitary foragers', but that does not mean that they are not social. Moreover, designating their social organisation as 'solitary', implies that their way of life is uniform in all species. It has, however, emerged over the last decades that all of them exhibit not only some kind of social network but also that those networks differ among species. There is a need to classify these social networks in the same manner. as with group-living (gregarious) animals if we wish to link up the different forms of primate social organisation with ecological, morphological or phylogenetic variables. In this review, we establish a basic classification based on spatial relations and sociality in order to describe and cope properly with the social organisation patterns of the different species of nocturnal prosimians and other mammals that do not forage in cohesive groups. In attempting to trace the ancestral pattern of primate social organisation the Malagasy mouse and dwarf lemurs and the Afro-Asian bushbabies and lorises are of special interest because they are thought to approach the ancestral conditions most closely. These species have generally been believed to exhibit a dispersed harem system as their pattern of social organisation ('dispersed' means that individuals forage solitarily but exhibit a social network). Therefore, the ancestral pattern of primate social organisation was inferred to be a dispersed harem. In fact, new field data on cheirogaleids combined with a review of patterns of social organisation in strepsirhines (lemurs, bushbabies and lorises) revealed that they exhibit either dispersed multi-male systems or dispersed monogamy rather than a dispersed harem system. Therefore, the concept of a dispersed harem system as the ancestral condition of primate social organisation can no longer be supported. In combination with data on social organisation patterns in 'primitive' placentals and marsupials, and in monotremes, it is in fact most probable that promiscuity is the ancestral pattern for mammalian social organisation. Subsequently, a dispersed multi-male system derived from promiscuity should be regarded as the ancestral condition for primates. We further suggest that the gregarious patterns of social organisation in Aotus and Avahi, and the dispersed form in Tarsius evolved from the gregarious patterns of diurnal primates rather than from the dispersed nocturnal type. It is consequently proposed that, in addition to Aotus and Tarsius, Avahi is also secondarily nocturnal.
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Objective: To examine whether the prone sleeping position may increase the risk for sudden infant death syndrome (SIDS), particularly in infants unused to prone sleep. Design: A 3-year (1987-1990) case-control study. Setting: Nationwide study in New Zealand. Subjects: Four hundred eighty-five infants who died of SIDS and 1800 controls. Main Outcome Measures: Infants were classified as unaccustomed to prone if their usual sleep position was nonprone and they were placed prone for the last sleep. Secondary prone was used to describe infants placed nonprone but found prone. Results: Infants usually and last placed nonprone were at the lowest risk for SIDS (odds ratio [OR], 1.0); those usually and last placed prone were at increased risk (adjusted OR, 4.6; 95% confidence interval, 3.4-6.3). Risk was greatly increased among infants unaccustomed to the prone position (adjusted OR, 19.3; 95% confidence interval, 8.2-44.8). These infants accounted for 8% (31/386) of all SIDS deaths. Ninety percent (28/31) of infants in this group were found prone, and 71% (20/28) of those found prone were found with their faces turned down into bedding-a position in which asphyxia has been implicated as a mechanism of death. In addition, 138 infants who died of SIDS were last placed nonprone. Forty-seven infants (34%) in this group were found prone (secondary prone), and 60% (28/47) of those found prone were found with their faces turned down into the bedding. This group accounted for 12% of all SIDS deaths. Most of these infants (91% [43/47]) were usually placed nonprone. Conclusions: Infants placed supine to sleep were at the lowest risk of SIDS, which supports the recommendation that this is the preferred sleeping position for healthy infants. Tn New Zealand, 20% of SIDS deaths involved lack of experience with the prone sleeping position. Our findings suggest the possibility that an infant's competence in escaping from potentially lethal situations during prone sleep (eg, the face-down position) may be impaired by inexperience in prone sleeping. Great caution should be exercised in placing infants unaccustomed to the prone sleeping position in the prone position.
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Introduction and Definitions A Potential Model for Sids and the Role of Environmental Stressors Conclusions and the Prevention of SIDS References
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There has been a major decrease in the incidence of sudden infant death syndrome (SIDS) since the American Academy of Pediatrics (AAP) released its recommendation in 1992 that infants be placed down for sleep in a nonprone position. Although the SIDS rate continues to fall, some of the recent decrease of the last several years may be a result of coding shifts to other causes of unexpected infant deaths. Since the AAP published its last statement on SIDS in 2000, several issues have become relevant, including the significant risk of side sleeping position; the AAP no longer recognizes side sleeping as a reasonable alternative to fully supine sleeping. The AAP also stresses the need to avoid redundant soft bedding and soft objects in the infant's sleeping environment, the hazards of adults sleeping with an infant in the same bed, the SIDS risk reduction associated with having infants sleep in the same room as adults and with using pacifiers at the time of sleep, the importance of educating secondary caregivers and neonatology practitioners on the importance of "back to sleep," and strategies to reduce the incidence of positional plagiocephaly associated with supine positioning. This statement reviews the evidence associated with these and other SIDS-related issues and proposes new recommendations for further reducing SIDS risk.
Article
Smith has written a most interesting obituary of Dave Sackett, whom I first met in 1995 at his office at the John Radcliffe Hospital in Oxford.1 I was publishing director for Churchill Livingstone and had made the appointment directly with him by email, of which he was a prolific and early user. Sackett sat at a very large screen, talking to …
Objective: To determine the relationship between cosleeping and sleep problems in cultures with very different sleep practices. Design: Interview study. Setting: Families in urban Japan and the United States identified through pediatric and other professional contacts. Participants: Parents of healthy 6- to 48-month-old children (56 Japanese parents and 61 white US parents). All children had been breast-fed and lived in 2-parent, middle-class households. Intervention: None Main Outcome Measure: Sleep practices and sleep problems. Results: More Japanese than US children coslept 3 or more times per week (59% vs 15%, P<.001). All cosleeping Japanese children regularly slept all night with their parents (vs 11% of US cosleepers, P<.001). Japanese and US children did not differ in part-night cosleeping (7% vs 13%, P =.37). Most Japanese children had adult company and body contact as they fell asleep, and fathers slept separately in 23% of families. A greater proportion ofUS children had regular bedtime struggles and night waking. Within the US sample, cosleeping was associated with more bedtime struggles (P<.001), night waking (P<.01), and overall stressful sleep problems (P<.01). In the Japanese sample, cosleeping was associated only with night waking (P<.05); however, the proportion of cosleeping Japanese children with frequent night waking was at the level reported for US children who slept alone (30% vs 23%. P =.47). Conclusions: Cultural differences seem to influence the relationship between sleep practices and sleep problems. The experience of the Japanese families indicates that cosleeping per se is not associated with increased sleep problems in early childhood.
Article
Objective. —To critically analyze reports that show a relationship between sudden infant death syndrome (SIDS) and the prone sleeping position in infants.Data Sources. —Peer-reviewed articles, published letters, book chapters, and local and national health statistics were used, without time or language restrictions. These studies represented three races, four continents, and seven countries; none was published in North America.Study Selection. —No studies were ignored, but only those with case controls were reviewed in detail; we regarded a recent cohort analytic (prospective) study as particularly strong, in addition to six before-and-after (intervention) trials.Data Extraction. —Hill's criteria for decision making were used to assess the quality and validity of the data.Data Synthesis. —Without exception, all studies demonstrated an increased risk for SIDS associated with the prone sleeping position. The published likelihood ratios (relative risk or odds ratio) for SIDS in the prone position compared with SIDS in any other position ranged from 3.5 to 9.3 in seven studies. Publicity against the use of the prone position has been associated with reduction of SIDS by 20% to 67%, paralleling the reduction in use of the prone position, with no increase in deaths from aspiration or in other diagnostic categories.Conclusions. —We recommend avoidance of the prone sleeping position for infants in the first 6 months of life unless there is a specific medical indication for it. Reports from the Netherlands, Great Britain, Australia, and New Zealand indicate that avoiding the prone position for infants in the first 6 months of life could reduce the number of SIDS deaths by as much as 50%. Unfortunately, these findings have received little attention in North America. We offer here an analysis of these reports so that physicians can assess the evidence and advise parents accordingly.(JAMA. 1992;267:2359-2362)
In Reply.—We thank Dr Newman for his comments, with which we have no major disagreement. It is true that physicians have benefited economically from the historic relationship between formula companies and physicians, and we implied that in our article. However, we cannot jump to the conclusion that this potential economic benefit was a primary motivating factor for our predecessors. As is usually the case, there are those who benefit economically from every humanitarian cause. We also agree with Dr Newman that take-home starter packages supplied by formula companies and distributed by hospital employees are a form of advertising, especially with accompanying toys and nursing bottles. Ironically, the vast majority of the information contained in these starter packets are guides to breastfeeding. The starter packet information also emphasizes that mothers should consult their physicians for advice on infant nutrition. A discussion of this form of advertising was inadvertently left out
Objective To examine whether the prone sleeping position may increase the risk for sudden infant death syndrome (SIDS), particularly in infants unused to prone sleep. Design A 3-year (1987-1990) case-control study. Setting Nationwide study in New Zealand. Subjects Four hundred eighty-five infants who died of SIDS and 1800 controls. Main Outcome Measures Infants were classified as unaccustomed to prone if their usual sleep position was nonprone and they were placed prone for the last sleep. Secondary prone was used to describe infants placed nonprone but found prone. Results Infants usually and last placed nonprone were at the lowest risk for SIDS (odds ratio [OR], 1.0); those usually and last placed prone were at increased risk (adjusted OR, 4.6; 95% confidence interval, 3.4-6.3). Risk was greatly increased among infants unaccustomed to the prone position (adjusted OR, 19.3; 95% confidence interval, 8.2-44.8). These infants accounted for 8% (31/386) of all SIDS deaths. Ninety percent (28/ 31) of infants in this group were found prone, and 71% (20/28) of those found prone were found with their faces turned down into bedding—a position in which asphyxia has been implicated as a mechanism of death. In addition, 138 infants who died of SIDS were last placed nonprone. Forty-seven infants (34%) in this group were found prone (secondary prone), and 60% (28/47) of those found prone were found with their faces turned down into the bedding. This group accounted for 12% of all SIDS deaths. Most of these infants (91% [43/47]) were usually placed nonprone. Conclusions Infants placed supine to sleep were at the lowest risk of SIDS, which supports the recommendation that this is the preferred sleeping position for healthy infants. In New Zealand, 20% of SIDS deaths involved lack of experience with the prone sleeping position. Our findings suggest the possibility that an infant's competence in escaping from potentially lethal situations during prone sleep (eg, the face-down position) may be impaired by inexperience in prone sleeping. Great caution should be exercised in placing infants unaccustomed to the prone sleeping position in the prone position.
Article
Dyadic co-sleeping (mother–baby) is a common strategy for night-time infant care in the majority of world cultures. Triadic co-sleeping (mother–father–baby) is less common, although still widely practised cross-culturally. This paper examines triadic co-sleeping in an opportunistic sample of parents from the North Tees region of England, and explores fathers' expectations and experiences of sleeping with their babies. Using a prospective study design, 36 sets of parents, pre- and post-natally, were interviewed about infant care strategies, particularly at night. Although they did not anticipate sleeping with their infants at the pre-natal interview, the majority of fathers (81%) had done so by the time of the second interview. First-time fathers were afraid that they would squash or suffocate the baby in their sleep, and some were concerned that the infant's presence would adversely affect their own sleep. Fathers used a variety of strategies to help overcome their initial fears of co-sleeping. Among those for whom triadic co-sleeping became a regular night-time infant care strategy, the pleasures of prolonged intimate contact with their infant were clearly apparent. It is suggested that the experience of sleeping with their infant ameliorates some of the distancing effects felt by fathers outside the breast-feeding relationship, and helps encourage paternal involvement in night-time infant care-giving. Copyright © 2000 John Wiley & Sons, Ltd.
Article
This paper extends the evolutionary and developmental research model for SIDS presented in previous articles (McKenna 1990a, 1990b). Data from variety of fields were used to show why we should expect human infants to be physiologically responsive in a beneficial way to parental contact, one form of which is parent-infant co-sleeping. It was suggested that on-going sensory exchanges (touch, movement, smell, temperature, etc.) between co-sleeping parent-infant pairs might diminish the chances of an infantile cardiac-respiratory crisis (such as those suspected to occur in some SIDS cases).In this article we review recent epidemiological data and sleep research findings on SIDS to show how they relate to evolutionary and cross-cultural perspectives. Results of a preliminary study of the co-sleeping behavior of mother-infant pairs indicate that, with respect to sleep, arousal, and respiratory patterns, co-sleeping mother-infant pairs affect each other in potentially important ways. We suggest specifically that co-sleeping may shorten periods of consolidated sleep among young infants by causing them to arouse more frequently. Moreover, we suggest that partner-induced arousals might help the infant to confront sleep crises more competently. In the long run, these arousals might prevent the premature emergence of prolonged (adultlike) sleep bouts from which some infants have difficulty arousing-especially during a breathing pause or apnea.
Book
As a group, western diseases such as type 2 diabetes, cardiovascular disease, breast cancer, allergies and mental health problems constitute one of the major problems facing humans at the beginning of the 21st century, particularly as they extend into poorer countries. An evolutionary perspective has much to offer standard biomedical understandings of western diseases. At the heart of this approach is the notion that human evolution occurred in circumstances very different from the modern affluent western environment and that, as a consequence, human biology is not adapted to the contemporary western environment. Written with an anthropological perspective and aimed at advanced undergraduates and graduates taking courses in the ecology and evolution of disease, Tessa Pollard applies and extends this evolutionary perspective by analysing trends in rates of western diseases and providing a new synthesis of current understandings of evolutionary processes, and of the biology and epidemiology of disease.
Article
Descriptive and quantitative observations were made of wild Guinea baboons (Papio papio) at a regularly used sleeping tree (Ceiba pentandra) in Senegal. Observations concentrated on the transition from darkness before sunrise until the baboons had left the tree. Behavior at sleeping sites is affected by a variety of social and nonsocial factors. Sleeping postures were adjusted during the night and to suit weather conditions. The baboons began to leave the tree earlier before sunrise in the dry season, especially on moonlit mornings. This might reflect increased foraging demands in the dry season. Sleeping parties were larger in the wet season, the difference being mainly due to juveniles. Huddling in the sleeping tree was little affected by weather conditions. The most common sleeping huddles consisted of adult females and young; huddles rarely contained more than one adult male. Although the sleeping tree was a safe refuge from leopards, the first baboon to leave the tree in the morning was usually an adult male. It has been hypothesized that the buildup of intestinal parasites in feces below sleeping trees influences the use of the trees by baboons; this did not occur here.
Article
This chapter discusses on the available information on sleep in wild monkeys and apes: like where they sleep, why certain locations might seem favorable or not, with whom the primates sleep, and what they do during the night and early morning. It will be seen that the securing of suitable sleeping sites can be a significant factor in the distribution and behavior of primates and that sleeping habits themselves are modified within overall adaptive patterns of activity. The chapter is intended to help socioecologists formulate questions about sleeping habits and to help sleep researchers, whose theoretical progress has been slowed due to availability of minimum records concerning the sleep of animals in their natural habitat. In captivity, studies of sleep have been largely restricted to physiological investigations, especially electrophysiology. In captivity schedules of food availability are controllable, permitting analysis of this variable on activity profiles including retiring and awakening times. Finally, social interaction is usually easier to monitor in captive primates than in free-ranging ones.