Search

Item does not contain fulltext Are impulsive behaviors an adaptive response to living in harsh or unpredictable environments? Formal models help address this question by providing cost-benefit analyses across a broad range of environmental conditions, but their various results have not been systematically integrated. Here, we survey models from diverse disciplines including psychology, biology, economics, and management to develop a conceptual framework of impulsivity. Using this framework, we integrated results from 30 models to review whether impulsivity is adaptive across a range of environmental conditions. We focus on information impulsivity, that is, acting without considering consequences, and temporal impulsivity, that is, the tendency to pick sooner outcomes over later ones. Results show that both types are adaptive when individuals are close to a critical threshold (e.g., bankruptcy), resources are predictable, or interruptions are common. When resources are scarce, impulsivity can be adaptive or maladaptive, depending on the type and degree of scarcity. Information impulsivity is also adaptive when environments do not change over time or change very often (but maladaptive in between), or if local resource patches have similar properties, reducing the need to gather further information. Temporal impulsivity is adaptive when environments do not change over time and when local resource patches differ. Our review shows theoreticians how ideas from different disciplines are connected, affords formal modelers to see similarities and differences between their own models and those of others, and informs researchers about which empirical predictions generalize across a broad range of environmental conditions and which ones do not. To end, we provide concrete recommendations for future empirical studies. 33 p.

Although early-life adversity can undermine healthy development, an evolutionary-developmental perspective implies that children growing up in harsh environments will develop intact, or even enhanced, skills for solving problems in high‐adversity contexts (i.e., 'hidden talents'). This Element situates the hidden talents model within a larger interdisciplinary framework. Summarizing theory and research on hidden talents, it proposes that stress-adapted skills represent a form of adaptive intelligence enabling individuals to function within the constraints of harsh environments. It discusses potential applications of this perspective to multiple sectors concerned with youth from harsh environments, including education, social services, and juvenile justice, and compares the hidden talents model with contemporary developmental resilience models. The hidden talents approach, it concludes, offers exciting directions for research on childhood adversity, with translational implications for leveraging stress-adapted skills to more effectively tailor education, jobs, and interventions to fit the needs of individuals from a diverse range of life circumstances.

In many countries, standardized math tests are important for achieving academic success. Here, we examine whether content of items, the story that explains a mathematical question, biases performance of low-SES students. In a large-scale cohort study of Trends in International Mathematics and Science Studies (TIMSS)—including data from 58 different countries from students in grades 4 and 8 (N = 5,501,165)—we examine whether item content that is more likely associated with major challenges for low-SES students (money, food, social relationships) improves their performance, compared with their average math performance. In contrast to our preregistered predictions, results show that low-SES students scored lower on items with this specific content than expected based on individual’s average performance. The effect sizes are considerable: on average, the chance to answer correctly is 18% lower. These results provide new insights in features of tests that disadvantage low-SES students and have implications for fair testing.

Contains fulltext : 201963.pdf (Publisher’s version ) (Open Access) This article focuses on the division of labor between evolution and development in solving sequential, state-dependent decision problems. Currently, behavioral ecologists tend to use dynamic programming methods to study such problems. These methods are successful at predicting animal behavior in a variety of contexts. However, they depend on a distinct set of assumptions. Here, we argue that behavioral ecology will benefit from drawing more than it currently does on a complementary collection of tools, called reinforcement learning methods. These methods allow for the study of behavior in highly complex environments, which conventional dynamic programming methods do not feasibly address. In addition, reinforcement learning methods are well-suited to studying how biological mechanisms solve developmental and learning problems. For instance, we can use them to study simple rules that perform well in complex environments. Or to investigate under what conditions natural selection favors fixed, non-plastic traits (which do not vary across individuals), cue-driven-switch plasticity (innate instructions for adaptive behavioral development based on experience), or developmental selection (the incremental acquisition of adaptive behavior based on experience). If natural selection favors developmental selection, which includes learning from environmental feedback, we can also make predictions about the design of reward systems. Our paper is written in an accessible manner and for a broad audience, though we believe some novel insights can be drawn from our discussion. We hope our paper will help advance the emerging bridge connecting the fields of behavioral ecology and reinforcement learning. 7 p.

Contains fulltext : 221814.pdf (Publisher’s version ) (Open Access) Over the past decade, there is increasing interest in the ways in which environmental unpredictability shapes human life history development. However, progress is hindered by two theoretical ambiguities. The first is that conceptual definitions of environmental unpredictability are not precise enough to be able to express them in statistical terms. The second is that there are different implicit hypotheses about the proximate mechanisms that detect unpredictability, which have not been explicitly described and compared. The first is the ancestral cue perspective, which proposes that humans evolved to detect cues (e.g., loss of a parent, residential changes) that indicated high environmental unpredictability across evolutionary history. The second is the statistical learning perspective, which proposes that organisms estimate the level of unpredictability from lived experiences across development (e.g., prediction errors encountered through time). In this paper, we address both sources of ambiguity. First, we describe the possible statistical properties of unpredictability. Second, we outline the ancestral cue and statistical learning perspectives and their implications for the measurement of environmental unpredictability. Our goal is to provide concrete steps toward better conceptualization and measurement of environmental unpredictability from both approaches. Doing so will refine our understanding of environmental unpredictability and its connection to life history development. 7 p.

Although growing up in stressful conditions can undermine mental abilities, people in harsh environments may develop intact, or even enhanced, social and cognitive abilities for solving problems in high‐adversity contexts (i.e. ‘hidden talents’). We examine whether childhood and current exposure to violence are associated with memory (number of learning rounds needed to memorize relations between items) and reasoning performance (accuracy in deducing a novel relation) on transitive inference tasks involving both violence‐relevant and violence‐neutral social information (social dominance vs. chronological age). We hypothesized that individuals who had more exposure to violence would perform better than individuals with less exposure on the social dominance task. We tested this hypothesis in a preregistered study in 100 Dutch college students and 99 Dutch community participants. We found that more exposure to violence was associated with lower overall memory performance, but not with reasoning performance. However, the main effects of current (but not childhood) exposure to violence on memory were qualified by significant interaction effects. More current exposure to neighborhood violence was associated with worse memory for age relations, but not with memory for dominance relations. By contrast, more current personal involvement in violence was associated with better memory for dominance relations, but not with memory for age relations. These results suggest incomplete transfer of learning and memory abilities across contents. This pattern of results, which supports a combination of deficits and ‘hidden talents,’ is striking in relation to the broader developmental literature, which has nearly exclusively reported deficits in people from harsh conditions. A video abstract of this article can be viewed at: https://youtu.be/e4ePmSzZsuc., People who grow up in stressful conditions may develop ‘hidden talents’: intact, or even enhanced, abilities for solving problems in high‐adversity contexts. We find partial support for this hypothesis. In our study, more current exposure to violence predicts intact or even enhanced memory for social dominance relationships, but more childhood exposure to violence predicts impaired memory for social dominance relationships.

Contains fulltext : 219353.pdf (Publisher’s version ) (Open Access) Evolutionary social scientists have argued that impulsive behavior is adaptive in harsh and unpredictable conditions. Is this true? This paper presents a mathematical model that computes the optimal level of impulsivity in environments varying in harshness and unpredictability. We focus on information impulsivity, or choosing to act without gathering or considering information about the consequences of one's actions. We explore two notions of harshness: the mean level of resources (e.g., food) and the mean level of extrinsic events (e.g., being the victim of a random attack). We explore three notions of unpredictability: variation in resources, variation in extrinsic events, and the interruption risk (the chance that a resource becomes unavailable). We also explore interactions between harshness and unpredictability. Our general model suggests four broad conclusions. First, impulsive behavior is not always adaptive in harsh and unpredictable conditions; rather, this depends on the exact definition of harshness, unpredictability, and impulsivity. Second, impulsive behavior may be adaptive in environments in which the quality of resources is low or high, but is less likely to be adaptive when their quality is moderate. Third, impulsive behavior may be adaptive when resource encounters are likely to be interrupted. Fourth, extrinsic events have only a limited effect on whether impulsive behavior is adaptive. We discuss the implications of these findings for future research, consider several limitations, and suggest future directions. 13 p.

Item does not contain fulltext 3 p.

Item does not contain fulltext It is well established that people living in adverse conditions tend to score lower on a variety of social and cognitive tests. However, recent research shows that people may also develop 'hidden talents', that is, mental abilities that are enhanced through adversity. The hidden talents program sets out to document these abilities, their development, and their manifestations in different contexts. Although this approach has led to new insights and findings, it also comes with theoretical and methodological challenges. Here, we discuss six of these challenges. We conclude that the hidden talents approach is promising, but there is much scope for refining ideas and testing assumptions. We discuss our goal to advance this research program with integrity despite the current incentives in science. 13 p.

Contains fulltext : 192527.pdf (Publisher’s version ) (Open Access) Some scholars think that Open Science practices constrain researchers in ways that reduce their creativity, arguing, for instance, that preregistration discourages data exploration and so stifles discovery. In this article, we argue the opposite: Open Science practices are liberating and can foster creativity. Open Science practices are liberating because they (a) enable us to explore data transparently and comfortably; (b) reward quality, which is under our control, rather than outcomes, which are not; and (c) reduce the choke hold of needing to find "positive" results for career advancement. Open Science practices can foster creativity because they cultivate an open and flexible mind-set, create a more collaborative and constructive climate, and generate more accurate information and make it more accessible. In sum, Open Science liberates researchers more than it constrains them. 9 p.

Life history theory developed as a branch of formal evolutionary theory concerned with the fitness consequences of allocating energy to reproduction, growth and self-maintenance across the life course. More recently, researchers have advocated its relevance to many psychological and social-science questions. As a scientific paradigm expands its range, its parts can become conceptually isolated from one another, so that in the end it is no longer held together by a common core of shared ideas. Here, we investigate the life history theory literature using quantitative bibliometric methods based on patterns of citation. We found that the literature up to and including 2010 was relatively coherent: it drew on a shared body of core references, and had only weak cluster divisions running along taxonomic lines. The post-2010 literature is more fragmented: it has more marked cluster boundaries, including boundaries within the literature on humans. Specifically, there are two clusters of human literature based around the idea of a fast-slow continuum of individual differences in behaviour that are bibliometrically isolated from the rest of the literature. We also find some evidence suggesting a relative decline in formal mathematical modelling. We point out that the human fast-slow continuum literature is conceptually closer to the non-human ‘pace of life’ literature than to the non-human literature usually referred to as ‘life history theory’.

Item does not contain fulltext Cultural transmission is often viewed as a domain-general process. However, a growing literature suggests that learnability is influenced by content and context. The idea of a learnability landscape is introduced as a way of representing the effects of interacting factors on how easily information is acquired. Extending prior work (Barrett & Broesch, ), learnability of danger and other properties is compared for animals, artifacts, and foods in the urban American children (ages 4-5) and in the Shuar children in Ecuador (ages 4-9). There is an advantage for acquiring danger information that is strongest for animals and weakest for artifacts in both populations, with culture-specific variations. The potential of learnability landscapes for assessing biological and cultural influences on cultural transmission is discussed. 12 p.

Contains fulltext : 149519.pdf (Publisher’s version ) (Closed access) In environments that are harsh and unpredictable, people are typically more vigilant, act more impulsively, and discount the future more. In this paper, we argue that these behaviors reflect a present-orientation produced by biological adaptations, despite potential harm to health and wellbeing. We review recent studies showing that people in stressful environments have a stronger preference for immediate over delayed rewards, have children at a younger age, and develop enhanced cognition for dealing with threat and rapidly changing conditions, compared with people from supportive environments. Moreover, people from supportive environments, when exposed to harsh-unpredictable environmental cues, shift toward a present-orientation. These findings underscore the benefits of integrating evolutionary and developmental psychology. 5 p.

Contains fulltext : 219116.pdf (Publisher’s version ) (Open Access) The term 'life-history theory' (LHT) is increasingly often invoked in psychology, as a framework for integrating understanding of psychological traits into a broader evolutionary context. Although LHT as presented in psychology papers (LHT-P) is typically described as a straightforward extension of the theoretical principles from evolutionary biology that bear the same name (LHT-E), the two bodies of work are not well integrated. Here, through a close reading of recent papers, we argue that LHT-E and LHT-P are different research programmes in the Lakatosian sense. The core of LHT-E is built around ultimate evolutionary explanation, via explicit mathematical modelling, of how selection can drive divergent evolution of populations or species living under different demographies or ecologies. The core of LHT-P concerns measurement of covariation, across individuals, of multiple psychological traits; the proximate goals these serve; and their relation to childhood experience. Some of the links between LHT-E and LHT-P are false friends. For example, elements that are marginal in LHT-E are core commitments of LHT-P, and where explanatory principles are transferred from one to the other, nuance can be lost in transmission. The methodological rules for what grounds a prediction in theory are different in the two cases. Though there are major differences between LHT-E and LHT-P at present, there is much potential for greater integration in the future, through both theoretical modelling and further empirical research. This article is part of the theme issue 'Life history and learning: how childhood, caregiving and old age shape cognition and culture in humans and other animals'. 9 p.

Contains fulltext : 213684.pdf (Publisher’s version ) (Open Access) In the past decade, there has been monumental progress in our understanding of the neurobiological basis of sensitive periods. Little is known, however, about the evolution of sensitive periods. Recent studies have started to address this gap. Biologists have built mathematical models exploring the environmental conditions in which sensitive periods are likely to evolve. These models investigate how mechanisms of plasticity can respond optimally to experience during an individual’s lifetime. This paper discusses the central tenets, insights, and predictions of these models, in relation to empirical work on humans and other animals. We also discuss which future models are needed to improve the bridge between theory and data, advancing their synergy. Our paper is written in an accessible manner and for a broad audience. We hope our work will contribute to recently emerging connections between the fields of developmental neuroscience and evolutionary biology. 12 p.

Bjorklund synthesizes promising research directions in developmental psychology using an evolutionary framework. In general terms, we agree with Bjorklund: Evolutionary theory has the potential to serve as a metatheory for developmental psychology. However, as currently used in psychology, evolutionary theory is far from reaching this potential. In evolutionary biology, formal mathematical models are the norm. In developmental psychology, verbal models are the norm. In order to reach its potential, evolutionary developmental psychology needs to embrace formal modeling.

Item does not contain fulltext People who grow up under stressful conditions tend to score lower on conventional assessments of cognitive abilities. They might, however, develop enhanced mental skills and abilities for solving problems that are more ecologically relevant to them. We present 2 studies examining whether psychosocial adversity (i.e., exposure to neighborhood violence and to harsh parenting) enhances the ability to detect deception. Our results, based on Signal Detection and Bayesian analyses, are mixed. In Study 1, we find no support for our hypothesis that exposure to psychosocial adversity enhances deception detection ability. In Study 2, we do find that only harsher parenting predicts greater accuracy. This evidence is either weak or strong, depending on whether we compare our hypothesis to the null hypothesis or an impairment model, respectively. In both studies, we find no relationship between neighborhood violence and accuracy. Although the implications of our findings are modest, we hope they will encourage future research focused on the skills and abilities of people who develop in harsh environments. 12 p.

Contains fulltext : 195174.pdf (Publisher’s version ) (Open Access) In the last decades, developmental origins of health and disease (DOHaD) has emerged as a central framework for studying early-life effects, that is, the impact of fetal and early postnatal experience on adult functioning. Apace with empirical progress, theoreticians have built mathematical models that provide novel insights for DOHaD. This article focuses on three of these insights, which show the power of environmental noise (i.e., imperfect indicators of current and future conditions) in shaping development. Such noise can produce: (a) detrimental outcomes even in ontogenetically stable environments, (b) individual differences in sensitive periods, and (c) early-life effects tailored to predicted future somatic states. We argue that these insights extend DOHaD and offer new research directions. 15 p.

Contains fulltext : 178669.pdf (Publisher’s version ) (Open Access) The present contribution highlights the importance of context while investigating dishonesty in collaborative settings. 3 p.

Pepper & Nettle's paper exemplifies an emerging resistance against an exclusive focus on deficits in people who come from harsh environments. We extend their model by arguing for a perspective that includes not only contextually appropriate responses but also strengths – that is, enhanced mental skills and abilities. Such a well-rounded approach can be leveraged in education, jobs, and interventions.

We recommend extending CLASH by incorporating two evolutionary accounts of the shift toward fast life histories under harsh, unpredictable conditions. These accounts, if integrated with CLASH, make different predictions about the distributions of aggression and violence within and between societies. We discuss these predictions and propose ways of testing them.

Item does not contain fulltext In the short history of behavioral immune system (BIS) research, scholars have developed a number of empirical strategies for testing BIS hypotheses. These strategies have led to a wide variety of methods for testing (putatively) similar BIS hypotheses. The current article provides an overview of the 3 most frequent methods used in BIS research: cross-population correlations, experimental priming, and surveying individual differences. We first review and question the fundamental assumptions underlying each method. Then, we question the degree to which these methods can be used to test the same hypotheses. Finally, we use these methodological considerations to propose directions for future, theory-driven research on the BIS.

Item does not contain fulltext Harshness and unpredictability early in life appear to be independently associated with long-term developmental outcomes, with environmental stressors affecting parental investment (e.g., responsiveness), which then shapes child development (e.g., onset of puberty). Research has detailed mediating physiological pathways, but has not specified how children transform experiences with their parents' and others' responsiveness into cognitive estimates about environmental harshness or unpredictability. In this article, we analyze this estimation process drawing on the study of contingency analysis. We propose that harshness and unpredictability produce distinct contingency profiles, and that children use these profiles to separately estimate each dimension. We conclude with six empirical predictions. 6 p.

Item does not contain fulltext Dozens of studies show that bystanders are less likely to help victims as bystander number increases. However, these studies model one particular situation, in which victims need only one helper. Using a multi-player dictator game, we study a different but common situation, in which a recipient’s welfare increases with the amount of help, and donors can share the burden of helping. We find that dictators transfer less when there are more dictators, and recipients earn less when there are multiple dictators. This effect persisted despite mechanisms eliminating uncertainty about other dictators’ behavior (a strategy method and communication). In a typical public goods game, people seem to transform the situation into an assurance game, willing to contribute if certain others will too. Despite similarities, people do not treat a recipient’s welfare like a public good. Instead, people seem to transform the situation into a prisoner’s dilemma, refusing to help whatever others do. 13 p.

Contains fulltext : 116457.pdf (Publisher’s version ) (Closed access) A predominant view in psychology is that early psychosocial adversity (e.g., abuse) impairs cognition, because children from stressful backgrounds (e.g., violent households) score lower on standard tests of intelligence, language, memory, inhibition, and other abilities. However, recent studies indicate that these people may exhibit improved detection, learning, and memory on tasks involving stimuli that are ecologically relevant to them (e.g., dangers), compared with safely nurtured peers. These findings contradict the view that cognition of stressed people is generally impaired; they suggest, rather, that these people’s minds are developmentally specialized toward local environmental conditions. Here, we review recent research supporting this hypothesis. In addition, we propose that novel studies should examine whether stressed children show not only improved detection but also improved memory and reasoning on tasks involving stimuli that are ecologically relevant to them. Finally, we discuss clinical implications of switching from conceptualizing stressed minds as “adapted” rather than “impaired.” 6 p.

We welcome the generalization by Del Giudice [1] of our model investigating the evolvability conditions for predictive adaptive responses (PARs) in long-lived species like humans [2]. In our original approach, environmental conditions in 1 year were modelled as the sum of the conditions in the previous year plus a perturbation term to represent exogenous sources of change. The perturbation terms were independent from year to year. If the exogenous perturbation forces are themselves temporally autocorrelated, then environmental change is described by a more complex autoregressive structure than the one used in our original model, one in which conditions in the current year are influenced by conditions in the previous year and the one before that. Del Giudice shows that when dependencies between successive years take this more complex form, the present becomes in effect a better guide to the future than it would otherwise have been. This makes the external PAR (using conditions experienced early in ontogeny as a guide to the likely adult external environment) an adaptive strategy under a somewhat wider range of conditions that those we originally reported. The objective for our paper was to galvanize theoretical progress in an area where adaptive hypotheses have been discussed for some time without agreement about whether they are likely to be right, and without exposure of the precise assumptions on which they depend. We recognize that our initial model was not exhaustive; it provided a contribution, hopefully, to the eventual construction of a whole library of related models examining how developmental trajectories might evolve under different environmental regimes. It will be this library of cases taken together—rather than any single one—that will lead to general understanding. The modelling endeavour is also not isolated from empirical work. To quote George Box, who died in 2013, ‘science is a means whereby learning is achieved, not by mere theoretical speculation on the one hand, nor by the undirected accumulation of practical facts on the other, but rather by a motivated iteration between theory and practice’ [3, p. 791]. Our model aimed to make an initial bridge between adaptive hypotheses about PARs, on the one hand, and empirically measurable features of the environments inhabited by humans, on the other. Del Giudice's model is welcome because it creates a second iteration, incorporating more detailed information about how environments vary to refine the model. We hope that his paper and ours will stimulate greater empirical research on environmental variation as experienced by individuals and populations (something that has also been called for elsewhere [4]). It may well be that some environmental forces are well captured by our original model, whereas others are not so well captured and require more complex specifications. Future empirical work will make this clearer. An even more important thing that George Box taught us was to ‘remember that all models are wrong; the practical question is how wrong do they have to be to not be useful’ [5, p. 74]. Our model contained a highly simplified representation of how organisms experience the early environment and how that environment might change. Our main conclusions were that, for a long-lived organism, there is only adaptive advantage to using early life as an indicator of the adult environment if (1) the level of annual autocorrelation in the environment is very high, and (2) the cues of environmental conditions received in early life are very accurate indicators of the present conditions. Del Giudice shows that allowing for delayed effects in environmental change leaves these two conclusions qualitatively intact, though the precise numbers change. Examining Del Giudice's fig. 1, panels (c) and (d) show that even where strong delayed effects are included, the adaptive advantage of plasticity is found only in the top right quadrant of the parameter space. The quantitative details of our evolvability criteria might need amending if the environmental factor under study were shown to exhibit strong delayed effects; where we specified an annual autocorrelation of at least 0.95, in fact 0.80 might be sufficient. Though this amendment is important, both models concur that there would have to be strong positive annual autocorrelation (not 0, 0.2 or 0.5, for example) coupled with high cue validities. When models using different assumptions come to qualitatively similar conclusions, it adds to our confidence about the robustness of those conclusions. We also note that quite different modelling approaches have recovered conclusions that are in some ways similar to ours [6–8]. Thus, we stick by our contention that conclusions (1) and (2) constrain the plausibility of the idea that humans use early-life cues to gain information about the likely external environment in adulthood, and reiterate our call to examine accommodation to the directly detrimental effects of early adversity on health as an alternative explanation of observed phenomena [9]. There has been a flurry of recent papers trying to test empirically what can broadly be characterized as PAR hypotheses. These are very diverse in design, character and results. Some find the predicted effects, while many do not [10–14]. Being more precise about the assumptions of the theory may help understand what the exact predictions are for particular systems and particular traits, and, especially, when we should expect to find PARs and when we should not.

Newborn infants have a special affinity for motion. It is not surprising, therefore, that the perception of biological motion has an important role in the early development of infants. This chapter describes the development of biological motion perception across early development. The chapter provides a critical discussion about whether “limitations” in infants’ visual system may reflect attunements that adaptively orient infants toward significant others (e.g., caregivers), describes the visual behavior of infants as evidence that they are actively selecting agents as targets of their attention, and provides a review of the overlaps between adult and infant vision research.

Item does not contain fulltext Interactions between evolutionary psychologists and developmental systems theorists have been largely antagonistic. This is unfortunate because potential synergies between the two approaches remain unexplored. This article presents a method that may help to bridge the divide, and that has proven fruitful in biology: dynamic optimization. Dynamic optimization integrates developmental systems theorists’ focus on dynamics and contingency with the ‘design stance’ of evolutionary psychology. It provides a theoretical framework as well as a set of tools for exploring the properties of developmental systems that natural selection might favor, given particular evolutionary ecologies. We also discuss limitations of the approach.

Item does not contain fulltext Previous research shows that men are more risk prone than women; single men take more risks than men involved in a romantic relationship; and men increase their level of risk taking in the presence of observers. We extend the existing literature with two studies. Our first study demonstrates that romantically involved men take less risk in the presence of women to the extent that they are more committed to their current partner. No such effect occurs in the presence of males. Our second study is an experiment revealing that men's beliefs about women's attitudes about risk taking causally influence men's level of risk taking. We developed a new measure of risk-taking—the Marble Risk Task, reminiscent of the computerized Balloon Analogue Risk Task (Lejuez et al., 2002), but designed to measure risk-taking outside of the laboratory and with real financial stakes—to show that single men adjust their level of risk taking to match what they believe women find attractive. Men involved in a relationship did the opposite: they adjust their behavior to not match what they believe women consider attractive—possibly with the goal of relationship maintenance. 4 p.

This study proposes the inclusion of peer relationships in a life history perspective on adolescent problem behavior. Longitudinal analyses were used to examine deviant peer clustering as the mediating link between attenuated family ties, peer marginalization, and social disadvantage in early adolescence and sexual promiscuity in middle adolescence and childbearing by early adulthood. Specifically, 998 youth and their families were assessed at age 11 years and periodically through age 24 years. Structural equation modeling revealed that the peer-enhanced life history model provided a good fit to the longitudinal data, with deviant peer clustering strongly predicting adolescent sexual promiscuity and other correlated problem behaviors. Sexual promiscuity, as expected, also strongly predicted the number of children by age 22–24 years. Consistent with a life history perspective, family social disadvantage directly predicted deviant peer clustering and number of children in early adulthood, controlling for all other variables in the model. These data suggest that deviant peer clustering is a core dimension of a fast life history strategy, with strong links to sexual activity and childbearing. The implications of these findings are discussed with respect to the need to integrate an evolutionary-based model of self-organized peer groups in developmental and intervention science.

Item does not contain fulltext This article discusses 3 ways in which adaptive developmental mechanisms may produce maladaptive outcomes. First, natural selection may favor risky strategies that enhance fitness on average but which have detrimental consequences for a subset of individuals. Second, mismatch may result when organisms experience environmental change during ontogeny, for instance, because they move from one environment to another. Third, organisms may learn about their environment in order to develop an appropriate phenotype; when cues indicate the environmental state probabilistically, as opposed to deterministically, sampling processes may produce mismatch. For each source of maladaptation, we present a selection of the relevant empirical research and illustrate how models from evolutionary biology can be used to make predictions about maladaptation. We also discuss what data can be collected to test these models in humans. Our goal is to show that evolutionary approaches not only yield insights into adaptive outcomes but can also illuminate the conditions leading to maladaptation. This perspective provides additional nuance to the dialectic between the developmental psychopathology model and evolutionary developmental psychology. 15 p.

Item does not contain fulltext Many studies in humans have shown that adverse experience in early life is associated with accelerated reproductive timing, and there is comparative evidence for similar effects in other animals. There are two different classes of adaptive explanation for associations between early-life adversity and accelerated reproduction, both based on the idea of predictive adaptive responses (PARs). According to external PAR hypotheses, early-life adversity provides a ‘weather forecast’ of the environmental conditions into which the individual will mature, and it is adaptive for the individual to develop an appropriate phenotype for this anticipated environment. In internal PAR hypotheses, early-life adversity has a lasting negative impact on the individual's somatic state, such that her health is likely to fail more rapidly as she gets older, and there is an advantage to adjusting her reproductive schedule accordingly. We use a model of fluctuating environments to derive evolveability conditions for acceleration of reproductive timing in response to early-life adversity in a long-lived organism. For acceleration to evolve via the external PAR process, early-life cues must have a high degree of validity and the level of annual autocorrelation in the individual's environment must be almost perfect. For acceleration to evolve via the internal PAR process requires that early-life experience must determine a significant fraction of the variance in survival prospects in adulthood. The two processes are not mutually exclusive, and mechanisms for calibrating reproductive timing on the basis of early experience could evolve through a combination of the predictive value of early-life adversity for the later environment and its negative impact on somatic state. 9 p.

Item does not contain fulltext Two significant questions in cognitive and developmental science are first, whether objects and events are selected for attention based on their features (featural processing) or the configuration of their features (configural processing), and second, how these modes of processing develop. These questions have been addressed in part with experiments focused on infants’ perception of faces, human body shapes, and biological motion of individual agents. Here, we investigate 4- and 10-month-old infants’ (N = 192) attention to social motions, specifically to chasing—a ubiquitous, ancient, and fitness-relevant mode of interaction. We constructed computer-generated animations of chasing that had three properties: acceleration, high turning rates, and attraction (“heat-seeking”). In the first experiment we showed chasing side-by-side with a control display of inanimate, billiard-ball-like motions. Infants strongly preferred attending to chasing. In the next three studies, we systematically investigated the effect of each property in turn (acceleration, turning, and attraction) by showing a display of that property side-by-side with the control display. Infants preferentially attended to acceleration, and to attraction, but not to turning. If infants preferred chasing for its configuration, then the sum of the effect sizes of individual properties should be smaller than their combined effects. That is not what we found: instead, on three measures of visual behavior, the summed effects of individual properties equaled (or exceeded) that of chasing. Moreover, although attraction drew little attention and turning no attention at all, acceleration drew (nearly) as much attention as chasing. Our results thus provide evidence that infants preferred chasing because of its features, not its configuration.

Contains fulltext : 90154.pdf (Publisher’s version ) (Closed access) Research has shown that male risk taking is enhanced by the presence of observers. However, naturalistic observations and laboratory experiments have provided mixed evidence as to whether male physical risk taking is primarily directed at females, at other males, or both. We present a behavioral experiment in virtual reality in which males ( N = 72) crossed an ominous bridge over a steep valley — either in the presence of a male virtual observer, a female virtual observer, or alone. A male or female experimenter was present while the participants crossed the bridge. Our results show that males crossed the bridge faster in the presence of a female experimenter than in the presence of a male experimenter. Follow up tests revealed that the experimenter effect was driven by the condition in which the virtual observer was female. This finding is consistent with previous work suggesting that male physical risk taking is primarily directed at females. 12 p.