In this study, 1.5-year-olds were taught a novel word. Some children were familiarized with the word's phonological form before learning the word's meaning. Fidelity of phonological encoding was tested in a picture-fixation task using correctly pronounced and mispronounced stimuli. Only children with additional exposure in familiarization showed reduced recognition performance given slight mispronunciations relative to correct pronunciations; children with fewer exposures did not. Mathematical modeling of vocabulary exposure indicated that children may hear thousands of words frequently enough for accurate encoding. The results provide evidence compatible with partial failure of phonological encoding at 19 months of age, demonstrate that this limitation in learning does not always hinder word recognition, and show the value of infants' word-form encoding in early lexical development.
The present study demonstrated that individual differences in cross-modal transfer showed continuity over a 10-year span. Tactual-visual tasks, requiring visual recognition of shapes that had previously been felt but not seen, were given to full-term and preterm children at 2 ages, 1 and 11 years. Cross-modal performance showed a left-hand advantage at 11 years and, for both groups, cross-age correlations were significant when tactual exploration at 11 years was done with the left hand (r = .34-.36). The continuity showed some specificity in that the infant measure did not relate to other types of cross-modal performance at 11 years and was not dependent on aspects of spatial ability involving form perception. This continuity accounted for most of the previously reported relation of infant cross-modal ability to 11-year IQ.
The development of speech perception during the 1st year reflects increasing attunement to native language features, but the mechanisms underlying this development are not completely understood. One previous study linked reductions in nonnative speech discrimination to performance on nonlinguistic tasks, whereas other studies have shown associations between speech perception and vocabulary growth. The present study examined relationships among these abilities in 11-month-old infants using a conditioned head-turn test of native and nonnative speech sound discrimination, nonlinguistic object-retrieval tasks requiring attention and inhibitory control, and the MacArthur-Bates Communicative Development Inventory (L. Fenson et al., 1993). Native speech discrimination was positively linked to receptive vocabulary size but not to the cognitive control tasks, whereas nonnative speech discrimination was negatively linked to cognitive control scores but not to vocabulary size. Speech discrimination, vocabulary size, and cognitive control scores were not associated with more general cognitive measures. These results suggest specific relationships between domain-general inhibitory control processes and the ability to ignore variation in speech that is irrelevant to the native language and between the development of native language speech perception and vocabulary.
A terrorist attack is an adverse event characterized by both an event-specific stressor and concern about future threats. Little is known about age differences in responses to terrorism. This longitudinal study examined generalized distress, posttraumatic stress responses, and fear of future attacks following the September 11, 2001 (9/11) terrorist attacks among a large U.S. national sample of adults (N = 2,240) aged 18-101 years. Individuals completed Web-based surveys up to 6 times over 3 years post 9/11. Multilevel models revealed different age-related patterns for distress, posttraumatic stress, and ongoing fear of future attacks. Specifically, older age was associated with lower overall levels of general distress, a steeper decline in posttraumatic stress over time, and less change in fear of future terrorist attacks over the 3 years. Understanding age differences in response to the stress of terrorism adds to the growing body of work on age differences in reactions to adversity. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
To study sources of individual differences in pubertal development, the authors fit a sex-limitation common factor model to data reported, at ages 11 and 14 years, by 1,891 twin pairs on items that comprise the Pubertal Development Scale (PDS; A. C. Petersen, L. Crockett, M. Richards, & A. Boxer, 1988). The model divides variation into a general pubertal factor and item-specific variation and, in addition, decomposes it into constituent sources. In both boys and girls, genetic influences made the largest contribution to variance common to PDS items. Genetic and nonshared environmental factors accounted for variation specific to PDS items in boys, whereas for girls, common environmental influences were added for growth spurt and menarcheal status. For both common and item-specific variation, genetic effects were partially sex specific. Subsidiary analyses found accelerated maturation in both boys and girls who at age 14 were reared in father-absent homes.
Despite the large body of knowledge on adults suggesting that 2 basic types of mental spatial transformation-namely, object-based and egocentric perspective transformations-are dissociable and specialized for different situations, there is much less research investigating the developmental aspects of such spatial transformation systems. Here, an "own body transformation" paradigm and a letter transformation task were employed in a group of children ranging from 7 to 11 years of age to respectively investigate the development of egocentric perspective transformations and object-related transformations. A group of 30 young adults was also administered the 2 experimental tasks. Moreover, the Temperament and Character Inventory (Cloninger, Przybeck, Svrakic, & Wetzel, 1994) was also administered to children and adults with the goal of testing for possible influences of personality traits on imagined perspective transformation abilities. We found that egocentric perspective transformations develop later than object-based transformations-namely, from 8 rather than 7 years of age. We also found that high scores on temperament and character scales reflecting the acceptance of others (i.e., cooperativeness) were positively related to the ability to engage in imagined perspective transformations, especially when such ability first appears (i.e., at 8 years of age). These findings were held to support the view that the 2 mental spatial transformation systems are separated in that they follow 2 different developmental trajectories and are differentially influenced by personality traits in children. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
The findings of the 8 empirical articles in this special section make a convincing case for cross-generation continuities. It is proposed that parenting practices may serve as a mechanisms that accounts for these stabilities. Both biological and social interactional variables are examined as potential explanations for how this effect might come about.
This study investigated patterns of change in children's strategies for solving mathematical equivalence problems. The strategies children expressed in speech and in gesture were assessed both before and after an instructional intervention. In the intervention, children received either no input, accuracy feedback, or feedback plus instruction about a principle, an analogy, or a procedure. From pretest to posttest, many children changed both the variability of their strategy use and the content of their strategy repertoires. Patterns of change depended on type of instruction and on children's initial level of variability. Children who received instruction were especially likely to generate new strategies, and children with high variability were especially likely to abandon prior strategies. Gradual change was most common; however, many children modified their repertoires abruptly. Abrupt strategy change was especially prevalent among children who received procedure-based instruction and among children with low initial variability.
This study examined the main and interactive effects of multiple social risk factors and the preschool child factors of IQ and mental health on students' academic trajectories from 1st grade to 12th grade. A multiple risk score summarizing 10 environmental risk factors was calculated at 4 years of age for 145 families. Hierarchical linear modeling showed that high-risk students had lower grades and more absences from 1st grade to 12th grade than did low-risk students. Significant interactions between risk and child factors for students' grade point average (GPA) revealed that child factors had significant effects only for low-risk students. Higher IQ and better mental health improved the GPA trajectories of low-risk children but did not influence the GPA trajectories of high-risk children.
Carrying objects requires coordination of manual action and locomotion. This study investigated spontaneous carrying in 24 walkers who were 13 months old and 26 crawlers who were 13 months old during 1-hr, naturalistic observations in the infants' homes. Carrying was more common in walkers, but crawlers also carried objects. Typically, walkers carried objects in their hands, whereas crawlers multitasked by using their hands simultaneously for holding objects and supporting their bodies. Locomotor experience predicted frequency of carrying in both groups, suggesting that experienced crawlers and walkers perceive their increased abilities to handle objects while in motion. Despite additional biomechanical constraints imposed by holding an object, carrying may actually improve upright balance: Crawlers rarely fell while carrying an object, and walkers were more likely to fall without an object in hand than while carrying. Thus, without incurring an additional risk of falling, spontaneous carrying may provide infants with new avenues for combining locomotor and manual skills and for interacting with their environments.
Many studies have demonstrated that infants can attribute goals to observed actions, whether they are presented live by familiar agents or on a computer screen by abstract figures. However, because most, if not all, of these studies rely on the repeated action presentations typical of infant studies, it is not clear whether infants are simply recognizing the completed action as goal directed, or whether they can productively infer a not-yet-achieved outcome from an ongoing action. We investigated this question by presenting 13-month-old infants with a single animated chasing event. Infants looked longer at the outcome of this action when, given the opportunity, the chaser did not catch the chasee than when it did. Crucially, this result was dependent on whether the action could be construed as efficient with regard to this goal state. This finding suggests the ability to infer the goal of an ongoing novel action and illustrates the productivity of 1-year-olds' action understanding.
Four experiments were conducted to assess infants ability to solve isomorphic problems and to explore the nature of early representations. Ten- and 13-month-olds attempted to solve problems that required combining 2 subgoals to bring a toy (goal object) within reach. A problem-series paradigm was used in which 3 tasks differing in surface features but sharing common goal structures and similar solutions were presented. The results indicate that 13-month-olds transferred a modeled solution strategy across isomorphic problems, whereas 10-month-olds did so only after experiencing either multiple source problems or high perceptual similarity between problems. Comprehension of the relations between solution actions and outcome, and between tools and target object, appeared critical to transfer. The results suggest that 1-year-olds can construct relatively abstract and flexible mental representations and that analogical problem solving may be 1 of the major accomplishments during the 1st year of life.
One of the foundations of attachment theory is the notion that early care plays a key role in determining the quality of child-caregiver attachment relationships. Studies have consistently shown relations between maternal sensitivity and infant security. Further research is required to resolve issues arising from modest correlations, focus on research in stressful as opposed to ordinary contexts, and questions about the generality of results across cultures and social contexts and about the context specificity of caregiving behavior. This article addressed these issues in 2 studies of child care in home and hospital contexts. Q-sort scores derived from extended naturalistic observations were used. Results are discussed in terms of links between methodology and effect sizes, the generality of links between maternal care and child security, the need for further research on caregiving in ordinary and emergency situations, and the context sensitivity of maternal behavior.
We examined whether self-restraint in early childhood predicted individual differences in 3 executive functions (EFs; inhibiting prepotent responses, updating working memory, and shifting task sets) in late adolescence in a sample of approximately 950 twins. At ages 14, 20, 24, and 36 months, the children were shown an attractive toy and told not to touch it for 30 s. Latency to touch the toy increased with age, and latent class growth modeling distinguished 2 groups of children that differed in their latencies to touch the toy at all 4 time points. Using confirmatory factor analysis, we decomposed the 3 EFs (measured with latent variables at age 17 years) into a Common EF factor (isomorphic to response inhibition ability) and 2 factors specific to updating and shifting. Less-restrained children had significantly lower scores on the Common EF factor, equivalent scores on the Updating-Specific factor, and higher scores on the Shifting-Specific factor than did the more-restrained children. The less-restrained group also had lower IQ scores, but this effect was entirely mediated by the EF components. Twin models indicated that the associations were primarily genetic in origin for the Common EF variable but split between genetics and nonshared environment for the Shifting-Specific variable. These results suggest a biological relation between individual differences in self-restraint and EFs, one that begins early in life and persists into late adolescence.
The following experiments were designed to determine the age at which infants can first readily learn word--object pairings with only minimal exposure and without social or contextual support. To address this question, 8- to 14-month-old infants were tested on their ability to form word--object associations in a "switch" design. Infants were habituated to 2 word--object pairings and then tested with 1 trial that maintained a familiar word--object pairing and 1 that involved a familiar word and object in a new combination. Across 6 experiments, only 14-month-old infants formed word--object associations under these controlled testing conditions but appeared to do so only when the objects were moving. Although 8- to 12-month-olds did not form the associations, they appeared to process both the word and the object information. These studies provide strong evidence that 14-month-old infants can rapidly learn arbitrary associations between words and objects, that this ability appears to develop at about 14 months of age, and that the Switch design is a useful method for assessing word--object learning in infancy.
Fourteen- and 18-month-old infants observed an adult experiencing each of 2 objects (experienced objects) and then leaving the room; the infant then played with a 3rd object while the adult was gone (unexperienced object). The adult interacted with the 2 experienced objects in 1 of 3 ways: by (a) sharing them with the infant in an episode of joint engagement, (b) actively manipulating and inspecting them on his or her own as the infant watched (individual engagement), or (c) looking at them from a distance as the infant played with them (onlooking). As evidenced in a selection task, infants of both ages knew which objects had been experienced by the adult in the joint engagement condition, only the 18-month-olds knew this in the individual engagement condition, and infants at neither age knew this in the onlooking condition. These results suggest that infants are 1st able to determine what adults know (have experienced) on the basis of their direct, triadic engagements with them.
Although there is substantial evidence that 30-month-old children can reason about other people's desires, little is known about the developmental antecedents of this ability. A food-request procedure was devised to explore this understanding in 14- and 18-month-olds. Children observed an experimenter expressing disgust as she tasted 1 type of food and happiness as she lasted another type of food. They were then required to predict which food the experimenter would subsequently desire. The 14-month-olds responded egocentrically, offering whichever food they themselves preferred. However, 18-month-olds correctly inferred that the experimenter wanted the food associated with her prior positive affect. They were able to make this inference even when the experimenter's desires differed from their own. These data constitute the first empirical evidence that 18-month-olds are able to engage in some form of desire reasoning. Children not only inferred that another person held a desire, but also recognized how desires are related to emotions and understood something about the subjectivity of these desires.
By 14 months, infants have become exquisite observers of others' behavior and successful word learners. But do they coordinate their early observational and language capacities to gain insight into the intentions of others? Building upon Gergely, Bekkering, and Király's (2002) classic head-touch phenomenon, we consider the contribution of language to 14-month-old infants' imitation of an unconventional behavior (turning on a light with one's forehead, rather than hand). Providing a novel word ("I'm going to blick the light!") prompted infants to imitate; simply drawing attention to the action ("Look at this!"; "Look at what I'm doing!") did not. Thus, by 14 months, infants gain insight into the intentions of others by considering not only what we do but also what we say. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
Ten- and 14-month-old infants' gaze was recorded as the infants observed videos of different hand actions directed toward multiple goals. Infants observed an actor who (a) reached for objects and displaced them, (b) reached for objects and placed them inside containers, or (c) moved his fisted hand. Fourteen-month-olds, but not 10-month-olds, anticipated the goal of reaching actions but tracked all the other actions reactively. Fourteen-month-olds also produced more anticipatory gaze shifts during containment compared with displacement and differentiated between reaching actions dependent on whether the overall goal was to displace objects or place objects inside containers. These results demonstrate that action type and goal type modulate the latency of goal-directed gaze shifts in infants.
The genetic and environmental etiology of low general cognitive ability (g) during infancy and early childhood has not previously been investigated. The current study examined the genetic etiology of low cognitive ability at 14, 20, 24, and 36 months with twins from the MacArthur Longitudinal Twin Study. Low g groups were formed from the lowest 10th percentile at each age. Univariate probandwise concordance rates and DeFries-Fulker (J. C. DeFries & D. W. Fulker, 1985, 1988) multiple regression techniques suggest genetic etiology in low general cognitive ability groups. The stability of low general cognitive ability over time also appears to be primarily due to genetic factors. Although replication is necessary, these results suggest that the genetic etiology of low g during infancy and early childhood is at least as great as the heritability of g in the unselected population.
The genetic and environmental contributions to the development of general cognitive ability throughout the first 16 years of life were examined using sibling data from the Colorado Adoption Project. Correlations were analyzed along with structural equation models to characterize the genetic and environmental influences on longitudinal stability and instability. Intraclass correlations reflected both considerable genetic influence at each age and modest shared environmental influence within and across ages. Modeling results suggested that genetic factors mediated phenotypic stability throughout this entire period, whereas most age-to-age instability appeared to be due to nonshared environmental influences.
The present cross-sectional study investigated age and gender differences in motivational manifestations of the Big Five in a large German-speaking Internet sample (N = 19,022). Participants ranging in age from 16 to 60 years completed the Five Individual Reaction Norms Inventory (FIRNI; Denissen & Penke, 2008a), and two traditional Big Five measures. Age differences were found suggesting that mean levels of neuroticism and extraversion are negatively associated with age, whereas agreeableness and conscientiousness are positively associated. Openness to experience demonstrated a curvilinear association with age, with the highest mean levels in midlife. Gender differences were found suggesting that women, on average, have higher levels of neuroticism, extraversion, and agreeableness, while men are more open to experience. Neither the main effect of gender nor Age × Gender interactions were significant in the case of conscientiousness. In comparison to the 2 traditional Big Five measures, age differences in the motivational manifestations of the Big Five as assessed by the FIRNI were more pronounced, which might be explained by the greater developmental plasticity of flexible motivational processes or the intraindividual phrasing of the items of the FIRNI, compared to the kinds of behavioral descriptions that are emphasized in traditional Big Five items. The further study of such motivational processes might contribute to a better understanding of personality development. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
Two goals guided this study: (a) describe changes in infant fear and anger reactivity from 4 to 16 months and (b) examine the degree to which infant temperament, attentional regulation, and maternal sensitivity predict reactivity trajectories. Participants included 143 mothers and infants (57% male) who visited the laboratory at 4, 8, 12, and 16 months. Infant reactivity, regulation, and maternal sensitivity were assessed from laboratory situations; infant temperament was rated by mothers on the Infant Behavior Questionnaire (Rothbart, 1981). Hierarchical linear modeling indicated that overall, fear and anger reactivity increased with age, but the rate of increase for fear slowed over time. Maternal ratings of temperamental fear and anger each predicted laboratory ratings of fear and anger reactivity, respectively. Moreover, infants who showed less regulation showed greater fear reactivity and steeper increases in anger reactivity over time. Infants whose mothers were more sensitive showed slower increases in fear reactivity. Findings from this study suggest that it is important to consider both intrinsic and extrinsic factors to gain a better understanding of the processes that may be involved in the development of emotional reactivity systems.
Four experiments familiarized 6-, 9-, 12-, and 16-month-old infants to a solid block that was repeatedly lowered into a semitransparent container. In test trials the end state, containment, was either compatible or incompatible with the objects' size and position. In Experiment 1, infants saw the block and box successively before they observed the end state. This forced infants to attend to each object individually and memorize its size and position while observing the end state. In Experiments 2 and 3, the block and container were shown simultaneously, the block suspended above the container at a distance of either 25 cm (Experiment 2) or 2 cm (Experiment 3). The shorter distance made direct comparison easier to perform. In Experiment 4, the full event was shown in which the block was lowered inside the container from a distance of 25 cm. Infants' perception of containment was related to the visual information that was available. When the event made it easier to grasp the relevant information, infants could perceive whether the block could pass in the container at a progressively younger age.
Reports an error in "Mastering developmental transitions in young and middle adulthood: The interplay of openness to experience and traditional gender ideology on women's self-efficacy and subjective well-being" by David Weiss, Alexandra M. Freund and Bettina S. Wiese (Developmental Psychology, 2012[Nov], Vol 48, 1774-1784). In the article, Study 2 is mistakenly described as a 9-month longitudinal study. However, this study covered 11 months. (The following abstract of the original article appeared in record 2012-14966-001.) The present research focuses on 2 factors that might help or hurt women to cope with the uncertainties associated with developmental transitions in modern societies (i.e., starting one's first job, graduating from high school, reentry to work after parental leave). We investigate (a) the role of openness to experience in coping with challenging transitions and (b) the (mal)adaptive consequences of adopting a traditional gender ideology. Starting with the assumption that transitional uncertainty has different consequences for women high or low in openness to experience, a first experiment (N = 61; 18-30 years) demonstrated that self-efficacy and well-being decrease after being confronted with transitional uncertainty among women low in openness. Two longitudinal studies investigated the (mal)adaptive consequences of adopting a traditional gender ideology for women high or low in openness in dealing with challenging transitions. Study 2 examined whether endorsing or rejecting traditional gender role beliefs might help female (but not male) students to maintain a sense of self-efficacy and subjective well-being during the transition of graduating from high school (N = 520, 17-22 years). Study 3 (N = 297; 20-53 years) tested the same model for women in middle adulthood during the transition from parental leave to reentry into work life. For both studies, latent growth analyses showed that endorsing traditional gender role beliefs contributed to self-efficacy and subjective well-being among women low in openness. By contrast, for women high in openness, rejecting traditional gender role beliefs had a positive effect on their relative level of self-efficacy and subjective well-being. Functions of ideologies in the context of challenging transitions are discussed. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
Factors affecting joint visual attention in 12- and 18-month-olds were investigated. In Experiment 1 infants responded to 1 of 3 parental gestures: looking, looking and pointing, or looking, pointing, and verbalizing. Target objects were either identical to or distinctive from distractor objects. Targets were in front of or behind the infant to test G. E. Butterworth's (1991b) hypothesis that 12-month-olds do not follow gaze to objects behind them. Pointing elicited more episodes of joint visual attention than looking alone. Distinctive targets elicited more episodes of joint visual attention than identical targets. Although infants most reliably followed gestures to targets in front of them, even 12-month-olds followed gestures to targets behind them. In Experiment 2 parents were rotated so that the magnitude of their head turns to fixate front and back targets was equivalent. Infants looked more at front than at back targets, but there was also an effect of magnitude of head turn. Infants' relative neglect of back targets is partly due to the "size" of adult's gesture.
Several analyses were conducted on data from samples of adults between 18 and 58 years of age who completed the same cognitive tests after an interval ranging from less than 1 week to 35 years. Because the retest interval varied across individuals, it was possible to determine the length of time needed before the gains associated with a retest decreased to 0 and to obtain simultaneous estimates of the magnitude of effects associated with increased age and a prior assessment. The results indicated that for adults within this age range, 7 or more years were needed before positive retest effects were no longer detectable. Age effects in longitudinal comparisons could be interpreted in terms of large positive effects associated with a prior assessment and negative effects associated with age that were comparable in magnitude to those observed in cross-sectional comparisons.
In the present study, we investigated genetic and environmental effects on motor impulsivity from childhood to late adolescence using a longitudinal sample of twins from ages 9 to 18 years. Motor impulsivity was assessed using errors of commission (no-go errors) in a visual go/no-go task at 4 time points: ages 9-10, 11-13, 14-15, and 16-18 years. Significant genetic and nonshared environmental effects on motor impulsivity were found at each of the 4 waves of assessment with genetic factors explaining 22%-41% of the variance within each of the 4 waves. Phenotypically, children's average performance improved across age (i.e., fewer no-go errors during later assessments). Multivariate biometric analyses revealed that common genetic factors influenced 12%-40% of the variance in motor impulsivity across development, whereas nonshared environmental factors common to all time points contributed to 2%-52% of the variance. Nonshared environmental influences specific to each time point also significantly influenced motor impulsivity. Overall, results demonstrated that although genetic factors were critical to motor impulsivity across development, both common and specific nonshared environmental factors played a strong role in the development of motor impulsivity across age. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
This study examined the cognitive functioning in 236 infants at 8 and 18 months of age. Thirty-seven infants were heavily exposed to cocaine in-utero, 30 were lightly exposed, and 169 were not exposed to cocaine. Cognitive functioning was evaluated with the Bayley Scales of Infant Development (2nd ed.; N. Bayley, 1993) at both ages. Infant information processing was also assessed with an infant-controlled habituation procedure. Results indicated that (a) infants of cocaine-abusing women had higher neonatal medical and environmental risk scores; (b) at 8 months, exposure groups did not differ in Psychomotor Development Index, Mental Development Index (MDI) scores, or recovery to a novel stimulus; and (c) infants heavily exposed to cocaine or high environmental risk had a decrease in MDI scores from 8 to 18 months. These results were obtained when neonatal medical and environmental risk, as well as polydrug exposure, were controlled.
The social cognition and perception-action literatures are largely separate, both conceptually and empirically. However, both areas of research emphasize infants' emerging abilities to use available information--social and perceptual information, respectively--for making decisions about action. Borrowing methods from both research traditions, this study examined whether 18-month-old infants incorporate both social and perceptual information in their motor decisions. The infants' task was to determine whether to walk down slopes of varying risk levels as their mothers encouraged or discouraged walking. First, a psychophysical procedure was used to determine slopes that were safe, borderline, and risky for individual infants. Next, during a series of test trials, infants received mothers' advice about whether to walk. Infants used social information selectively: They ignored encouraging advice to walk down risky slopes and discouraging advice to avoid safe slopes, but they deferred to mothers' advice at borderline slopes. Findings indicate that 18-month-old infants correctly weigh competing sources of information when making decisions about motor action and that they rely on social information only when perceptual information is inadequate or uncertain.
Researchers know little about whether very young children can recognize objects originally introduced to them in a picture book when they encounter similar looking objects in various real-world contexts. The present studies used an imitation procedure to explore young children's ability to generalize a novel action sequence from a picture book to novel test conditions. The authors found that 18-month-olds imitated the action sequence from a book only when the conditions at testing matched those at encoding; altering the test stimuli or context disrupted imitation (Experiment 1A). In contrast, the 24-month-olds imitated the action sequence with changes to both the test context and stimuli (Experiment 1B). Moreover, although the 24-month-olds exhibited deferred imitation with no changes to the test conditions, they did not defer imitation with changes to the context and stimuli (Experiment 2). Two factors may account for the pattern of results: age-related changes in children's ability to utilize novel retrieval cues as well as their emerging ability to understand the representational nature of pictures.
Infants at 12 and 18 months of age played with 2 adults and 2 new toys. For a 3rd toy, however, 1 of the adults left the room while the child and the other adult played with it. This adult then returned, looked at all 3 toys aligned on a tray, showed great excitement ("Wow! Cool!"), and then asked, "Can you give it to me?' To retrieve the toy the adult wanted, infants had to (a) know that people attend to and get excited about new things and (b) identify what was new for the adult even though it was not new for them. Infants at both ages did this successfully, lending support to the hypothesis that 1-year-old infants possess a genuine understanding of other persons as intentional and attentional agents.
Deferred imitation was used to trace changes in memory retrieval by 18-30-month-olds. In all experiments, an adult demonstrated 2 sets of actions using 2 different sets of stimuli. In Experiments 1A and 1B, independent groups of infants were tested immediately or after a 24-hr delay. Each infant was tested with 1 set of stimuli from the original demonstration and 1 set of stimuli that was different. Recall of the target actions when tested with different stimuli increased as a function of age, particularly after a delay. In Experiment 2, infants were provided with a unique verbal label for the stimuli during the demonstration and the test. The verbal label facilitated performance by 24-month-olds tested with different stimuli but had no effect on performance by 18-month-olds. One hallmark of memory development appears to be an age-related increase in the range of effective retrieval cues for a particular memory.
We used longitudinal data from a birth cohort study, the Fragile Families and Child Wellbeing Study, to investigate the links between Head Start and school readiness in a large and diverse sample of urban children at age 5 (N = 2,803; 18 cities). We found that Head Start attendance was associated with enhanced cognitive ability and social competence and reduced attention problems but not reduced internalizing or externalizing behavior problems. These findings were robust to model specifications (including models with city-fixed effects and propensity-scoring matching). Furthermore, the effects of Head Start varied by the reference group. Head Start was associated with improved cognitive development when compared with parental care or other nonparental care, as well as improved social competence (compared with parental care) and reduced attention problems (compared with other nonparental care). In contrast, compared with attendance at pre-kindergarten or other center-based care, Head Start attendance was not associated with cognitive gains but with improved social competence and reduced attention and externalizing behavior problems (compared with attendance at other center-based care). These associations were not moderated by child gender or race/ethnicity.
This study investigated (a) stability and change in infant affective responses to the still-face interaction, (b) whether maternal depression affected infant responses, and (c) whether responses to the still-face interaction predicted toddler problem behaviors. Infants (63 girls and 66 boys) of European American mothers (67 depressed and 62 nondepressed) were observed in the still-face interaction at 2, 4, and 6 months. Affect and gaze were coded on a 1-s time base. There were stable individual differences in gazing away and in rates of negative affect. Developmental change occurred only for gazing away, which increased. At 18 months, infants who failed to smile at 6 months in the still-face interaction showed more externalizing-type behaviors than did other toddlers. Infants who failed to cry at 6 months showed fewer internalizing-type behaviors. Mothers' current depressive symptoms and infants' earlier responses to the still-face interaction made independent, comparable contributions to problem behaviors at 18 months.
In the present study, between-family analyses of data from adolescent twin girls offer new evidence that early menarche is associated with earlier initiation and greater frequency of smoking and drinking. The role of personality factors and peer relationships in that association was investigated, and little support was found for their involvement. Novel within-family analyses replicating associations of substance use with pubertal timing in contrasts of twin sisters selected for extreme discordance for age at menarche are reported. Within-family replications demonstrated that the association of pubertal timing with substance use cannot be explained solely by between-family confounds. Within-family analyses demonstrated contextual modulation of the influence of pubertal timing: Its impact on drinking frequency is apparent only among girls in urban settings. Sibling comparisons illustrate a promising analytic tool for studying diverse developmental outcomes.
Perceived control plays an important role for health across adulthood and old age. However, little is known about the factors that account for such associations and whether changes in control (or control trajectory) uniquely predict major health outcomes over and above mean levels of control. Using data from the nationwide Americans' Changing Lives Study (House et al., 1990; N = 2,840, M age at T2: 56.32 years, range: 28-99, 64% women), we examined the extent to which mean levels and rates of change in perceived control over 16 years predict all-cause mortality over a 19-year follow-up period. Shared growth-survival models revealed that higher levels of and more positive changes in perceived control were associated with longer survival times, independent of sociodemographic correlates. We found that level effects of control were accounted for by well-being and health factors, whereas the change effects of control were not. Analyses also indicated an age-differential pattern, with the predictive effects of both levels and trajectories of control declining in old age. We discuss possible pathways through which perceived control operates to facilitate key health outcomes and consider how their malleability and effectiveness may change with increasing age. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
In the prevention of physical aggression, possible etiological links with language development are rarely taken into account. Indeed, little is known about when language and aggressive behavior become linked during development and which mechanisms are responsible for this association. This study investigated the association between physical aggression and language in late infancy with a genetic design that involved 562 19-month-old twins. A modest but significant correlation (r = -.20) was found between physical aggression and expressive vocabulary. Substantial heritability was found for physical aggression. Quantitative genetic modeling suggests that the correlation between expressive vocabulary and physical aggression cannot be explained by shared etiologies. However, phenotype-to-phenotype models indicate that the covariation can be entirely accounted for by a significant phenotypic path from expressive vocabulary to physical aggression. The implications of these results for early prevention of chronic physical aggression are discussed.
Five standard Piagetian tests were administered to 180 adolescents between the ages of 10 and 15 years. The results were compared with those obtained in 1967 and in 1972 for similar participant samples. At equal ages, today's adolescents exhibited a higher level of cognitive development than the adolescents of 20 or 30 years ago. The amount of gain observed varied across tasks, being very large for combinatory thought but mixed for conservation. This acceleration of cognitive development can partially explain the continuous rise in intelligence test performance (Flynn effect).
Although the relation between TV-violence viewing and aggression in childhood has been clearly demonstrated, only a few studies have examined this relation from childhood to adulthood, and these studies of children growing up in the 1960s reported significant relations only for boys. The current study examines the longitudinal relations between TV-violence viewing at ages 6 to 10 and adult aggressive behavior about 15 years later for a sample growing up in the 1970s and 1980s. Follow-up archival data (N = 450) and interview data (N = 329) reveal that childhood exposure to media violence predicts young adult aggressive behavior for both males and females. Identification with aggressive TV characters and perceived realism of TV violence also predict later aggression. These relations persist even when the effects of socioeconomic status, intellectual ability, and a variety of parenting factors are controlled.
This study used data from the Project on Human Development in Chicago Neighborhoods, a multilevel, longitudinal study of children sampled from 80 diverse neighborhoods, to explore associations among changes in neighborhood poverty from 1990 to 2000 and changes in youth's internalizing problems and property and violent offenses over 6 years (N = 3,324; mean age across waves = 12.6 years). After accounting for a host of background characteristics and weighting for the propensity to stay in the original sampled neighborhood, results indicated that neighborhood poverty dynamics were unfavorably linked to boys' problem behaviors. In high-poverty (>30% in 1990) neighborhoods, decreasing poverty was associated with boys' greater internalizing problems and higher probability of increasing in violent behavior than stable neighborhood poverty. In moderate-poverty (20%-30% in 1990) neighborhoods, boys in neighborhoods that got poorer had more internalizing problems than boys in stably poor neighborhoods. Likewise, in low-poverty (<20% in 1990) neighborhoods, increasing poverty was associated with boys' higher probability of increasing in violent behavior than stable neighborhood poverty. Effect sizes were larger in high- and moderate-poverty neighborhoods than in low-poverty neighborhoods. This study complements the neighborhood mobility literature and has implications for interventions aimed at community revitalization.
The Swedish Adoption/Twin Study of Aging is a semilongitudinal study of the aging of mental abilities in monozygotic and dizygotic twins. In the article by D. Finkel, N. L. Pedersen, R. Plomin, and G. E. McClearn (1998), data from 602 individuals were used to investigate developmental changes on 14 measures of mental ability as well as changes in the heritability of these abilities. This commentary details a number of problems with the design and analysis of data reported by Finkel et al., problems that leave the results difficult to interpret, and then provides suggestions for more fruitful approaches for analyzing data from such studies in the future.
This article addresses concerns raised by M. C. Neale (1999) in his commentary on the D. A. Bussell et al. (1999) Nonshared Environment in Adolescent Development (NEAD) study. These concerns fall into two categories: (a) model assumptions and sample design and (b) testing of alternative models. The validity of the assumptions of quantitative genetic models is a concern for all researchers in this area. Discussion of those assumptions in this reply is brief and focuses on those most relevant to the NEAD sample. The two alternative models proposed by Neale were designed to provide alternatives to the large shared environmental effect found in the original report of Bussell et al. Because these alternative models did not provide a better fit, the appropriateness of Bussell et al.'s basic model and the importance of shared environmental influences for explaining the association among family subsystems are supported.
Processing speed was assessed at 5, 7, and 12 months in full-term and preterm infants (birth-weight < 1,750 g). Speed was gauged directly in a new task by presenting infants with a series of paired faces, one that remained the same across trials and one that changed; trials continued until infants showed a consistent novelty preference. At all ages, preterms required about 20% more trials and 30% more time than full-terms to reach criterion. Among preterms, slower processing was associated with greater medical risk (e.g., respiratory distress syndrome). Developmental trajectories for speed (and attention) were similar for both groups. Thus, the deficits in processing speed previously found for preterms in childhood are already present in the 1st year of life.
Before 12 months of age, infants have difficulties coordinating and sequencing their movements to retrieve an object concealed in a box. This study examined (a) whether young infants can discover effective retrieval solutions and consolidate movement coordination earlier if exposed regularly to such a task and (b) whether different environments, indexed by box transparency, would impact the rate of learning and time of discovery of these solutions. Infants (N=12) were presented with an object retrieval task every week from 6 1/2 months of age until they were able to retrieve the toy from the box using coordinated two-handed patterns for 3 weeks. To reach that criterion, infants tested with an opaque box took 2 1/2 months and infants tested with a semitransparent box took 1 1/2 months. Both groups outperformed age-matched controls who received a one-time exposure to the task. Repeated exposure to the task and vision of the toy significantly enhanced this process of solution discovery.
Several aspects of visual attention and their implications for recognition memory were examined in a longitudinal sample of full-term and preterm (birth weight < 1,750 g) infants seen at 5, 7, and 12 months of age. At all 3 ages, full-terms had shorter look durations, faster shift rates, less off-task behavior, and higher novelty scores than preterms. Both groups followed similar developmental trajectories, with older infants having shorter looks and more shifts. Infants were consistent in attentional style across problems of the same type, across problems that used different types of stimuli (faces and patterns), and across the familiarization and test phases of this paired-comparison design; there was also modest cross-age stability. Shorter looks and higher shift rates during familiarization were related to better recognition memory, with shift rate adding to prediction independently of either peak or mean look. These findings underscore the importance of attention to infant information processing.
Findings are presented of a study of families created through surrogacy arrangements. Forty-two surrogacy families were compared with 51 egg-donation families and 80 natural-conception families on standardized interview and questionnaire measures of the psychological well-being of the parents, the quality of parent-child relationships, and infant temperament. The differences that were identified between the surrogacy families and the other family types indicated greater psychological well-being and adaptation to parenthood by mothers and fathers of children born through surrogacy arrangements than by the natural-conception parents.
Eighty 5.5- to 12.5-month-old infants participated in 4 delayed-response procedures challenging shortterm visuospatial memory (STVM), 2 that varied the time between presentation and search and 2 that varied the number of locations. Within each type of challenge, 1 task required a gaze response and 1 required a reach response. There was little improvement in STVM performance from 5.5 to 8 months and linear improvement in the percentage correct from 8 to 12 months, with overall STVM performance accounting for 66% of the variance in age. Improvement in searching multiple locations lagged behind improvement in spanning longer delays. Memory scores did not vary for the visual and manual tasks. Perseveration was greatest for reach responses, increased with challenge, and decreased with age. ((c) 2004 APA, all rights reserved)
By 3 years of age, children can solve tasks involving physical principles such as locating a ball that rolled down a ramp behind an occluder by the position of a partially visible solid wall (Berthier, DeBlois, Poirer, Novak, & Clifton, 2000; Hood, Carey, & Prasada, 2000). However, the extent to which children use physical information (the properties of the wall) remains unclear because spatial information would suffice (the location of the wall in relation to the ball). We confronted 2- to 6-year-old children with a ball resting on a shelf inside a clear plastic-fronted box. To retrieve the ball, children had to roll it away from a trap or barrier using their fingers. Crucially, a single object acted as a barrier or supporting surface in different conditions, thus requiring a flexible response. Preschoolers solved the task and the critical transfers from 2.5 years of age (Study 1). Interestingly, 2.5-year-olds required to use a tool to displace the ball performed significantly worse than those who could use their fingers (Study 2). In contrast, 2.5- to 4.5-year-olds failed a covered trap box that provided only 2-dimensional predictive cues without any visible physical information, and even 6.5-year-olds performed significantly worse on the covered task compared to the uncovered one (Studies 3 and 4). Our results suggest that children from around 2.5 years of age integrate spatial and physical information when solving problems like the trap box task, rather than simply exploit spatial relationships between features. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
Although many socialization agents influence children's behavior (D. L. Vandell, 2000), the evidence (e.g., from intervention studies) indicates that each exerts its influence only within its own domain. Context effects and genetic effects are among the confounding factors that make it impossible, given current data, to reject the null hypothesis of zero long-term effects of parenting on child outcomes. Problems with the prevailing view of development cannot be solved by invoking within-home environmental differences or gene- environment interactions. Group socialization theory can account for findings that do not fit the prevailing view. The theory attributes outside-the-home socialization to identification with a peer group and assimilation of group norms, but attributes nongenetic variation in personality to differentiation within the group. The latter proposition is still largely untested but other aspects of the theory are well supported by evidence.