Rebecca Sear

Rebecca Sear
London School of Hygiene and Tropical Medicine | LSHTM · Department of Population Health

About

138
Publications
46,546
Reads
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5,731
Citations
Citations since 2016
66 Research Items
3289 Citations
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
Additional affiliations
April 2012 - present
London School of Hygiene and Tropical Medicine
Position
  • Professor (Full)

Publications

Publications (138)
Article
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Demography, lacking an overarching theoretical framework of its own, has drawn on theories in many other social sciences to inform its analyses. The aim of this paper is to bring to the demographic community's attention research in the evolutionary sciences on fertility, and to demonstrate that evolutionary theory can be another useful tool in the...
Article
The emerging discipline of evolutionary medicine is breaking new ground in understanding why people become ill. However, the value of evolutionary analyses of human physiology and behaviour is only beginning to be recognised in the field of public health. Core principles come from life history theory, which analyses the allocation of finite amounts...
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Demography was heavily involved in the eugenics movement of the early twentieth century but, along with most other social science disciplines, largely rejected eugenic thinking in the decades after the Second World War. Eugenic ideology never entirely deserted academia, however, and in the twenty-first century, it is re-emerging into mainstream aca...
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The importance of social support for parental and child health and wellbeing is not yet sufficiently widely recognized. The widespread myth in Western contexts that the male breadwinner-female homemaker nuclear family is the 'traditional' family structure leads to a focus on mothers alone as the individuals with responsibility for child wellbeing....
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Background In South Asian countries, adolescent girls are generally embedded in multigenerational households. Nevertheless, public health research continues to focus on the nuclear family and overlook the role of grandmothers in adolescent socialization and the transfer of health information. This study compares family planning knowledge of adolesc...
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Human social relationships, often grounded in kinship, are being fundamentally altered by globalization as integration into geographically distant markets disrupts traditional kin based social networks. Religion plays a significant role in regulating social networks and may both stabilize extant networks as well as create new ones in ways that are...
Article
Measures of nutritional status are often used as markers of health, at both individual- and population-level. Different measures of nutritional status – such as height or weight, for example, – may have different associations with health outcomes because they reflect both current nutritional status and the accumulation of past health experiences, b...
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Background Environmental exposures in early life explain variability in many physiological and behavioural traits in adulthood. Recently, we showed that exposure to a composite marker of low maternal capital explained the clustering of adverse behavioural and physical traits in adult daughters in a Brazilian birth cohort. These associations were st...
Preprint
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In 2002, Lynn and Vanhanen produced a dataset which claimed to provide average ‘national IQs’ for nation-states worldwide. Despite extensive critique, this dataset, and subsequent updated versions, have been used in a large number of empirical publications. Here I evaluate the latest version, produced in 2019 by Lynn and Becker, and show that this...
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Complementing a recent systematic review and meta-analysis which showed that boys are more likely to be wasted, stunted, and underweight than girls, we conducted a narrative review to explore which early life mechanisms might underlie these sex differences. We addressed different themes, including maternal and newborn characteristics, immunology an...
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Evolutionary demographers often invoke tradeoffs between reproduction and survival to explain reductions in fertility during demographic transitions. The evidence for such tradeoffs in humans has been mixed, partly because tradeoffs may be masked by individual differences in quality or access to resources. Unmasking tradeoffs despite such phenotypi...
Preprint
Women around the world receive help with childrearing, much of which would have come from kin throughout most of human history. Market integration leads to less kin-dense social networks which may transform patterns of allomaternal care. Yet, few empirical studies have quantified the role of market integration in childcare patterns. We test the hyp...
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Several studies have found that parental absences in childhood are associated with individuals’ reproductive strategies later in life. However, these associations vary across populations and the reasons for this heterogeneity remain debated. In this paper, we examine the diversity of parental associations in three ways. First, we test whether diffe...
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Malnutrition among women of reproductive age is a significant public health concern in low- and middle-income countries. Of particular concern are undernutrition from underweight and iron deficiency, along with overweight and obesity, all of which have negative health consequences for mothers and children. Accumulating evidence suggests that risk f...
Article
Life history theory researchers often assume reproductive, parenting and health behaviours pattern across a fast-slow continuum, with ‘fast’ life histories (typified by short lifespans, early maturation and investing in quantity over quality of children) favoured in poor quality environments and/or when resources are scarce. Some researchers furthe...
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In high-income, low-fertility (HILF) settings, the mother’s partner is a key provider of childcare. However, it is not clear how mothers without partners draw on other sources of support to raise children. This paper reports the findings from a survey of 1532 women in the United Kingdom and the United States, in which women described who provided c...
Preprint
Expectations for having children are hypothesised to be predominantly influenced by societal family norms at young ages, and are adjusted during the life course in response to changing circumstances and new information. The onset of parenthood is likely to be a key event that affects expectations. This paper explores whether the expectations of wom...
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Population matters. Demographic patterns are both a cause and a consequence of human behaviour in other important domains, such as subsistence, cooperation, politics and culture. Demographers interested in contemporary and recent historical populations have rich data at their fingertips; the importance of demography means many interested parties ha...
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Background: Excess male morbidity and mortality is well recognised in neonatal medicine and infant health. In contrast, within global nutrition, it is commonly assumed that girls are more at risk of experiencing undernutrition. We aimed to explore evidence for any male/female differences in child undernutrition using anthropometric case definitions...
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Gender equity theories of fertility broadly predict that the lowest fertility in high-income settings will be seen in women facing a ‘dual burden’ of both paid and unpaid labour responsibilities, but that fertility will increase when male partners share domestic labour. Here we provide a critique of some gender equity theories of fertility in demog...
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Interest in incorporating life history research from evolutionary biology into the human sciences has grown rapidly in recent years. Two core features of this research have the potential to prove valuable in strengthening theoretical frameworks in the health and social sciences: the idea that there is a fundamental trade-off between reproduction an...
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Dizygotic twinning, the simultaneous birth of siblings when multiple ova are released, is an evolutionary paradox. Twin-bearing mothers often have elevated fitness, but despite twinning being heritable, twin births occur only at low frequencies in human populations. We resolve this paradox by showing that twinning and non-twinning are not competing...
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Many aspects of religious rituals suggest they provide adaptive benefits. Studies across societies consistently find that investments in ritual behaviour return high levels of cooperation. Another line of research finds that alloparental support to mothers increases maternal fertility and improves child outcomes. Although plausible, whether religio...
Preprint
Full-text available
Interest in incorporating life history research from evolutionary biology into the human sciences has grown rapidly in recent years. Two core features of this research have the potential to prove valuable in strengthening theoretical frameworks in the health and social sciences: the idea that these is a fundamental trade-off between reproduction an...
Preprint
Full-text available
Life-history theory researchers often assume reproductive, parenting and health behaviours pattern across a fast–slow continuum, with ‘fast’ life histories (typified by short lifespans, early maturation and investing in quantity over quality of children) favoured in poor quality environments and/or when resources are scarce. These ideas, with diffe...
Article
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Fathers favour sons, mothers don't discriminate: Sex-biased parental care in northwestern Tanzania - Volume 1 - Anushé Hassan, Susan B. Schaffnit, Rebecca Sear, Mark Urassa, David W. Lawson
Article
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Economic and evolutionary models of parental investment often predict education biases toward earlier-born children, resulting from either household resource dilution or parental preference. Previous research, however, has not always found these predicted biases—perhaps because in societies where children work, older children are more efficient at...
Article
Persistent interest lies in gender inequality, especially with regard to the favouring of sons over daughters. Economists are concerned with how privilege is transmitted across generations, and anthropologists have long studied sex-biased inheritance norms. There has, however, been no focused cross-cultural investigation of how parent–offspring cor...
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Background: Some individuals appear prone to multiple adverse outcomes, including poor health, school dropout, risky behavior and early reproduction. This clustering remains poorly understood. Drawing on evolutionary life history theory, we hypothesized that maternal investment in early life would predict the developmental trajectory and adult phen...
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We use the UK's Born in Bradford study to investigate whether women in lower‐quality environments are less likely to breastfeed. We use measures of physical environmental quality (water disinfectant by‐products (DBPs), air pollution, passive cigarette smoke, and household condition) alongside socioeconomic indicators, to explore in detail how diffe...
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Father absence in early life has been shown to be associated with accelerated reproductive development in girls. Evolutionary social scientists have proposed several adaptive hypotheses for this finding. Though there is variation in the detail of these hypotheses, they all assume that family environment in early life influences the development of l...
Article
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In this commentary, we consider how evolutionary biology’s life history theory(LHT) can be integrated with life course theorizing, to the benefit of both endeavors. We highlight areas where it can add value to existing work in life course theory (LCT), focusing on: how it can add an extra level of explanation, which may be helpful in understanding...
Article
A key demographic hypothesis has been that fertility declines rely on stopping at target parities, but emerging evidence suggests that women frequently reduce fertility without specific numeric targets. To assess the relative importance of these two paths to fertility decline, we develop a novel mixture model to estimate: (1) the proportion of wome...
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Embodied capital theory (ECT) argues that socioeconomic “modernization” leads to high-cost, high-return parental investments in education, in turn incentivizing demographic transitions to low fertility. However, few studies have directly investigated the proposed opportunity costs of schooling in contemporary developing populations undergoing socio...
Preprint
Full-text available
Father absence in early life is consistently shown to be associated with accelerated reproductive development in girls. Evolutionary social scientists have proposed several adaptive hypotheses for this finding. Though there is variation in the detail of these hypotheses, they all assume that family environment in early life influences the developme...
Article
Full-text available
Despite the tendency of some academic disciplines to assume that the nuclear family is normative, the family takes a number of different forms cross-culturally. Regardless of family form, family members typically cooperate in raising children. Intergenerational help (from grandparents to parents and children), for example, is a cross-cultural unive...
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Why do grandparents invest so heavily in their grandchildren and what impact does this investment have on families? A multitude of factors influence the roles grandparents play in their families. Here, we present an interdisciplinary perspective of grandparenting incorporating theory and research from evolutionary biology, sociology and economics....
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Pepper & Nettle offer a nuanced and humane view on poverty that should be required reading for policy makers, particularly those interested in “behaviour change” policy. We suggest, however, that the emphasis on “future-discounting” in this paper downplays the importance of differences in the payoffs to behaviours in the present and how these payof...
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Variation in male testosterone has been hypothesized to reflect the evolved hormonal regulation of investment in mating versus parenting effort. Supporting this hypothesis, numerous studies have observed lower testosterone in married men and fathers compared with unpartnered and childless men, consistent with relatively elevated resource allocation...
Article
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Background and Objectives: Breastfeeding is an important form of parental investment with clear health benefits. Despite this, rates remain low in the UK; understanding variation can therefore help improve interventions. Life history theory suggests that environmental quality may pattern maternal investment, including breastfeeding. We analyse a na...
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Low fertility across Europe highlights the need to understand reproductive decisions in high-income countries better. Availability of support may be one factor influencing reproductive decisions, though within high-income countries availability varies between environments, including socio-economic environments. We test whether receiving higher leve...
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BACKGROUND Support from families can reduce costs of reproduction and may therefore be associated with higher fertility for men and women. Family supportiveness, however, varies both between families - some families are more supportive than others - and within families over time - as the needs of recipients and the abilities of support givers chang...
Article
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Evolutionary anthropology has traditionally focused on the study of small-scale, largely self-sufficient societies. The increasing rarity of these societies underscores the importance of such research yet also suggests the need to understand the processes by which such societies are being lost—what we call “modernization”—and the effects of these p...
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Evolutionary anthropology has traditionally focused on the study of small-scale, largely self-sufficient societies. The increasing rarity of these societies underscores the importance of such research yet also suggests the need to understand the processes by which such societies are being lost—what we call “modernization”—and the effects of these p...
Article
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Is fertility relevant to evolutionary analyses conducted in modern industrial societies? This question has been the subject of a highly contentious debate, beginning in the late 1980s and continuing to this day. Researchers in both evolutionary and social sciences have argued that the measurement of fitness-related traits (e.g., fertility) offers l...
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Studies of the association between wealth and fertility in industrial populations have a rich history in the evolutionary literature, and they have been used to argue both for and against a behavioral ecological approach to explaining human variability. We consider that there are strong arguments in favor of measuring fertility (and proxies thereof...
Chapter
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A multitude of factors influence the role a grandfather plays in his family. This chapter presents an interdisciplinary perspective of grandfathering, incorporating research from the fields of evolutionary biology, sociology, economics and psychology. Examples will be used to show how these perspectives complement rather than compete with each othe...
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Several empirical observations suggest that when women have more autonomy over their reproductive decisions, fertility is lower. Some evolutionary theorists have interpreted this as evidence for sexual conflicts of interest, arguing that higher fertility is more adaptive for men than women. We suggest the assumptions underlying these arguments are...
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Previous research has found that the presence of grandparents, particularly grandmothers, is often positively associated with child survival. Little research has explored the potential mechanisms driving these associations. We use data from rural Guatemala to test whether contact with and direct investment (advice and financial) from grandparents i...
Article
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Decades of research on human fertility has presented a clear picture ofhowfertility varies, including its dramatic decline over the last two centuries in most parts of the world.Whyfertility varies, both between and within populations, is not nearly so well understood. Fertility is a complex phenomenon, partly physiologically and partly behavioural...
Article
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Previous research suggests that kin availability may be correlated with reproductive outcomes, but it is not clear that a causal relationship underlies these findings. Further, there is substantial variation in how kin availability is measured. Objective: We attempt to identify whether different measures of kin availability influence how kin affect...
Article
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Life history theory predicts that where mortality/morbidity is high, earlier reproduction will be favoured. A key component of reproductive decision-making in high income contexts is induced abortion. Accordingly, relationships between mortality/morbidity and ‘abortion proportion’ (proportion of conceptions ending in abortion) are explored at small...
Chapter
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Demography and evolutionary biology have a long history: Darwin was famously influenced by Malthus when developing his ideas on natural selection. The two disciplines remained closely associated throughout the early 20th century. They disassociated after the Second World War, but in recent decades lines of communication between the disciplines have...
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Background and objectives: Childhood family background is known to be associated with child growth and development, including the onset of puberty, but less is known about the influence of childhood family disruption on outcomes in later life. Given the associations between early family disruption and childhood development, we predicted that there...
Article
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Objectives: In high-income populations, evidence suggests that socioeconomic disadvantage early in life is correlated with reproductive strategy. Children growing up in unfavorable rearing environments tend to experience earlier sexual maturity and first births. Earlier first births may be associated with higher fertility, but links between socioe...
Chapter
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This section defines the term sociobiology, describes its origins in the work of Edward O. Wilson and how the discipline has developed over time. It also mentions how sociobiology may be applied to the study of sexual behaviour.
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Book review of "How We Do It: The Evolution and Future of Human Reproduction." 2013. By ROBERT MARTIN. New York: Basic Books
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A considerable body of evidence has now demonstrated positive correlations between grandparental presence and child health outcomes. It is typically assumed that such correlations exist because grandparental investment in their grandchildren improves child health and wellbeing. However, less is known about how grandparents allocate help to adult ch...
Article
Full-text available
Menopause remains an evolutionary puzzle, as humans are unique among primates in having a long post-fertile lifespan. One model proposes that intergenerational conflict in patrilocal populations favours female reproductive cessation. This model predicts that women should experience menopause earlier in groups with an evolutionary history of patrilo...
Data
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Kin are generally expected to behave more cooperatively with their relatives than with unrelated individuals, and this cooperative behavior may result in positive effects on fitness. Such kin effects are likely to be modified by resource availability: in contexts of resource stress, cooperation among kin may disappear or weaken as more energy is re...
Article
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Postdoctoral training is a typical step in the course of an academic career, but very little is known about postdoctoral researchers (PDRs) working in the UK. This study used an online survey to explore, for the first time, relevant environmental factors which may be linked to the research output of PDRs in terms of the number of peer-reviewed arti...
Preprint
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Background. Parental absences in childhood are often associated with accelerated reproductive maturity in humans. These results are counterintuitive for evolutionary social scientists because reductions in parental investment should be detrimental for offspring, but earlier reproduction is generally associated with higher fitness. In this paper we...
Article
Full-text available
Father absence is consistently associated with children’s reproductive outcomes in industrialized countries. It has been suggested that father absence acts as a cue to particular environmental conditions that influence life history strategies. Much less is known, however, about the effects of father absence on such outcomes in lower-income countrie...
Article
Full-text available
Childhood family structure has been shown to play an important role in shaping a child's life course development, especially in industrialised societies. One hypothesis which could explain such findings is that parental investment is likely to be diluted in families without both natural parents. Most empirical studies have examined the influence of...