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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.

Contains fulltext : 220707.pdf (Publisher’s version ) (Closed access) Although early-life adversity can undermine healthy development, children growing up in harsh environments may develop intact, or even enhanced, skills for solving problems in high-adversity contexts (i.e., "hidden talents"). Here we situate the hidden talents model within a larger interdisciplinary framework. Summarizing theory and research on hidden talents, we propose that stress-adapted skills represent a form of adaptive intelligence that enables individuals to function within the constraints of harsh, unpredictable environments. We discuss the alignment of the hidden talents model with current knowledge about human brain development following early adversity; examine potential applications of this perspective to multiple sectors concerned with youth from harsh environments, including education, social services, and juvenile justice; and compare the hidden talents model with contemporary developmental resilience models. We conclude that the hidden talents approach offers exciting new directions for research on developmental adaptations to childhood adversity, with translational implications for leveraging stress-adapted skills to more effectively tailor education, jobs, and interventions to fit the needs and potentials of individuals from a diverse range of life circumstances. This approach affords a well-rounded view of people who live with adversity that avoids stigma and communicates a novel, distinctive, and strength-based message. 19 p.

Contains fulltext : 240004.pdf (Publisher’s version ) (Open Access) Sensitive periods are widespread in nature, but their evolution is not well understood. Recent mathematical modeling has illuminated the conditions favoring the evolution of sensitive periods early in ontogeny. However, sensitive periods also exist at later stages of ontogeny, such as adolescence. Here, we present a mathematical model that explores the conditions that favor sensitive periods at later developmental stages. In our model, organisms use environmental cues to incrementally construct a phenotype that matches their environment. Unlike in previous models, the reliability of cues varies across ontogeny. We use stochastic dynamic programming to compute optimal policies for a range of evolutionary ecologies and then simulate developmental trajectories to obtain mature phenotypes. We measure changes in plasticity across ontogeny using study paradigms inspired by empirical research: adoption and cross-fostering. Our results show that sensitive periods only evolve later in ontogeny if the reliability of cues increases across ontogeny. The onset, duration, and offset of sensitive periods - and the magnitude of plasticity - depend on the specific parameter settings. If the reliability of cues decreases across ontogeny, sensitive periods are favored only early in ontogeny. These results are robust across different paradigms suggesting that empirical findings might be comparable despite different experimental designs. 14 p.

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.

Contains fulltext : 214941.pdf (Publisher’s version ) (Open Access) We present a consensus-based checklist to improve and document the transparency of research reports in social and behavioural research. An accompanying online application allows users to complete the form and generate a report that they can submit with their manuscript or post to a public repository. 3 p.

Author(s): Aczel, Balazs; Szaszi, Barnabas; Sarafoglou, Alexandra; Kekecs, Zoltan; Kucharský, Simon; Benjamin, Daniel; Chambers, Christopher D; Fisher, Agneta; Gelman, Andrew; Gernsbacher, Morton A; Ioannidis, John P; Johnson, Eric; Jonas, Kai; Kousta, Stavroula; Lilienfeld, Scott O; Lindsay, D Stephen; Morey, Candice C; Munafo, Marcus; Newell, Benjamin R; Pashler, Harold; Shanks, David R; Simons, Daniel J; Wicherts, Jelte M; Albarracin, Dolores; Anderson, Nicole D; Antonakis, John; Arkes, Hal R; Back, Mitja D; Banks, George C; Beevers, Christopher; Bennett, Andrew A; Bleidorn, Wiebke; Boyer, Ty W; Cacciari, Cristina; Carter, Alice S; Cesario, Joseph; Clifton, Charles; Conroy, Ronan M; Cortese, Mike; Cosci, Fiammetta; Cowan, Nelson; Crawford, Jarret; Crone, Eveline A; Curtin, John; Engle, Randall; Farrell, Simon; Fearon, Pasco; Fichman, Mark; Frankenhuis, Willem; Freund, Alexandra M; Gaskell, M Gareth; Giner-Sorolla, Roger; Green, Don P; Greene, Robert L; Harlow, Lisa L; de la Guardia, Fernando Hoces; Isaacowitz, Derek; Kolodner, Janet; Lieberman, Debra; Logan, Gordon D; Mendes, Wendy B; Moersdorf, Lea; Nyhan, Brendan; Pollack, Jeffrey; Sullivan, Christopher; Vazire, Simine; Wagenmakers, Eric-Jan | Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.

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Contains fulltext : 219115.pdf (Publisher’s version ) (Closed access) This special issue focuses on the relationship between life history and learning, especially during human evolution. 'Life history' refers to the developmental programme of an organism, including its period of immaturity, reproductive rate and timing, caregiving investment and longevity. Across many species an extended childhood and high caregiving investment appear to be correlated with particular kinds of plasticity and learning. Human life history is particularly distinctive; humans evolved an exceptionally long childhood and old age, and an unusually high level of caregiving investment, at the same time that they evolved distinctive capacities for cognition and culture. The contributors explore the relations between life history, plasticity and learning across a wide range of methods and populations, including theoretical and empirical work in biology, anthropology and developmental psychology. 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'. 6 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.

Contains fulltext : 201953.pdf (Publisher’s version ) (Open Access) The term 'life-history theory' is a familiar label in several disciplines. Life-history theory has its roots in evolutionary models of the fitness consequences of allocating energy to reproduction, growth and self-maintenance across the life course. Increasingly, the term is also used in the conceptual framing of psychological and social-science studies. As a scientific paradigm expands its range, its parts can become conceptually isolated from one another, even to the point that it is no longer held together by a common core of shared ideas. Here, we investigate the literature invoking the term 'life-history theory' using quantitative bibliometric methods based on patterns of shared citation. Results show 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, both between the human and non-human literatures, and within the human literature. In particular, two clusters of human research based on the idea of a fast-slow continuum of individual differences are bibliometrically isolated from the rest. We also find some evidence suggesting a decline over time in the incidence of formal modelling. We point out that the human fast-slow continuum literature is conceptually closer to the non-human 'pace-of-life' literature than it is to the formal life-history framework in ecology and evolution. 9 p.

There is enduring debate over the question of which early-life effects are adaptive and which ones are not. Mathematical modelling shows that early-life effects can be adaptive in environments that have particular statistical properties, such as reliable cues to current conditions and high autocorrelation of environmental states. However, few empirical studies have measured these properties, leading to an impasse. Progress, therefore, depends on research that quantifies cue reliability and autocorrelation of environmental parameters in real environments. These statistics may be different for social and non-social aspects of the environment. In this paper, we summarize evolutionary models of early-life effects. Then, we discuss empirical data on environmental statistics from a range of disciplines. We highlight cases where data on environmental statistics have been used to test competing explanations of early-life effects. We conclude by providing guidelines for new data collection and reflections on future directions. This article is part of the theme issue ‘Developing differences: early-life effects and evolutionary medicine'.

Contains fulltext : 204928.pdf (Publisher’s version ) (Open Access) It is undesirable when students attend institutions that are less selective than their academic credentials would permit (i.e., undermatching) because of the long-term consequences for their job opportunities and wages, in particular for students from low-socioeconomic (SES) backgrounds. Undermatching may also affect students’ satisfaction during college. Research from a life course perspective shows that subjective experiences during college may have long-term impact on adolescents’ development. However, little is known about the relation between undermatching and students’ subjective experiences during their years in college, and about whether this relation is moderated by SES. From an academic misalignment perspective, undermatching may lead to less satisfaction because undermatched students are not maximizing their potential. However, from a social misalignment perspective, experiences of social mismatch when low-SES students enter the most selective institutions are well documented, and such mismatch may be less pronounced in less selective institutions. Consequently, there may be a positive relation between undermatching and satisfaction with the social environment for low-SES students. The current study tested these relations by using propensity score matching (PSM) to analyse the association between undermatching, SES, and satisfaction among 21,452 respondents (67% female) among 1st, 2nd, 3th, and 4th year college students from a cohort study among students in the Netherlands (Dutch Student Monitor), all of whom were eligible for the most selective institutions. The results indicated a negative relation between undermatching and satisfaction with the social and academic environment, both for low- and high-SES students. The negative relation between undermatching and both forms of satisfaction increases toward the last year in college, especially for low-SES students. This lowered satisfaction in the final stage in higher education implies that the negative consequences of undermatching become more pronounced after students have become more integrated in their colleges. These findings have important implications for the understanding about undermatching in relation to students’ development and for the formulation of policies and programs for promoting social mobility. 15 p.

I argue that emotion research needs formal (mathematical) theory to address two central questions. How does evolution shape mechanisms of emotion development across generations, depending on environmental conditions? How do these mechanisms generate emotions, based on lifetime experience and current context? Formal modeling enables researchers to state ideas clearly and precisely, deduce predictions, and evaluate the fit between theory and data. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

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.

Contains fulltext : 216280.pdf (Publisher’s version ) (Open Access) On average, psychological variables are often statistically different in people living in poverty compared with people living in affluence. The default academic response to this pattern is often the deficit model: Poverty damages or impairs brain function, which leads to poor performance that only exacerbates the poverty. Deficits and damage are real phenomena. However, there are also other processes: People living in poverty may have made reasonable psychological responses to their circumstances or may have developed strengths that enhance their ability to cope with challenges in their lives. We illustrate these points by discussing the linked examples of time preference, early reproduction, and hidden talents. We argue for a balanced approach to the psychology of poverty that integrates deficit and strengths-based models. Future research could focus on the ways in which impairment and adaptation interact. 6 p.

Item does not contain fulltext Variation in life history (LH) traits along the fast-slow continuum (referred to as pace of life, POL) is thought to result from a trade-off between investments in current versus future reproduction. Originally developed for understanding variation in LH strategies at the among-population level, the POL theory has more recently been applied towards understanding variation in LH traits at the within-population level, and further extended to address the covariance of LH traits with additional behavioural and/or physiological traits, referred to as pace-of-life syndromes (POLS). The article by Réale et al. (Philos T Roy Soc B 365:4051-4063, 2010), which synthesized several earlier reviews and opinions on among-individual covariation between LH, behavioural, and physiological traits, and subsequent research testing POLS in a variety of species, have collectively been cited several hundreds of times - a trend that continues. These works have interdisciplinary impact, informing research in life history biology, behavioural and developmental biology, and the social sciences. In this paper, we review the existing theoretical POLS models that provide adaptive explanations for covariances between LH traits and additional behavioural and/or physiological traits while assuming a trade-off between current and future reproduction. We find that the set of relevant models is small. Moreover, models show that covariances between life history traits and behavioural or physiological traits can arise even in the absence of a current-future reproduction trade-off, implying that observing such covariances does not provide a strong indication regarding the process generating POLS. We discuss lessons learned from existing models of POLS, highlight key gaps in the modelling literature, and provide guidelines for better integration between theory and data. 12 p.

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 : 191999.pdf (Publisher’s version ) (Open Access) We used a Face-in-the-Crowd task to examine whether hostile environments predict enhanced detection of anger, and whether such enhanced cognition occurs for a di erent negative emotion, sadness, as well. We conducted a well-powered, preregistered study in 100 college students and 100 individuals from a community sample with greater exposure to hostile environments. At the group level, the community sample was less accurate at detecting both angry and sad faces than students; and, only students discriminated anger more accurately than sadness. At the individual level, having experienced more violence did not predict enhanced anger detection accuracy. In general, participants had a lower threshold (i.e., a more liberal criterion) for detecting emotion in response to anger than sadness. And, students had a higher threshold (i.e., a more conservative criterion) for detecting emotion than the community sample in response to both anger and sadness. Overall, these ndings contradict our hypothesis that exposure to hostile environments predicts enhanced danger detection. Rather, our community sample was more prone to over-perceiving emotions, consistent with previous studies showing bias in threat-exposed populations. Future work is needed to tease apart the conditions in which people exposed to social danger show enhanced accuracy or bias in their perception of emotions. 8 p.

Sensitive periods in development are widespread in nature. Many psychologists and biologists regard sensitive periods as byproducts of developmental processes. Although this view may be correct in some cases, it is unlikely to be the whole story. There is large variation in sensitive periods (a) between species in the same trait ( Beecher & Brenowitz, 2005 ), (b) between individuals of the same species ( Frankenhuis, Panchanathan, & Belsky, 2016 ), and (c) between different traits within a single individual ( Zeanah, Gunnar, McCall, Kreppner, & Fox, 2011 ). In this article, we discuss recent insights provided by formal models of the evolution of sensitive periods. These models help to identify the conditions in which sensitive periods are likely to evolve, and make predictions about the factors that affect their development. We conclude by discussing future directions for empirical research.

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.

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.

Item does not contain fulltext Sensitive periods, in which experience shapes phenotypic development to a larger extent than other periods, are widespread in nature. Despite a recent focus on neural–physiological explanation, few formal models have examined the evolutionary selection pressures that result in developmental mechanisms that produce sensitive periods. Here, we present such a model. We model development as a specialization process during which individuals incrementally adapt to local environmental conditions, while receiving a constant stream of cost-free, imperfect cues to the environmental state. We compute optimal developmental programmes across a range of ecological conditions and use these programmes to simulate developmental trajectories and obtain distributions of mature phenotypes. We highlight four main results. First, matching the empirical record, sensitive periods often result from experience or from a combination of age and experience, but rarely from age alone. Second, individual differences in sensitive periods emerge as a result of stochasticity in cues: individuals who obtain more consistent cue sets lose their plasticity at faster rates. Third, in some cases, experience shapes phenotypes only at a later life stage (lagged effects). Fourth, individuals might perseverate along developmental trajectories despite accumulating evidence suggesting the alternate trajectory is more likely to match the ecology. 8 p.

Contains fulltext : 151892.pdf (Publisher’s version ) (Closed access) Children vary in the extent to which their development is shaped by particular experiences (e.g. maltreatment, social support). This variation raises a question: Is there no single level of plasticity that maximizes biological fitness? One influential hypothesis states that when different levels of plasticity are optimal in different environmental states and the environment fluctuates unpredictably, natural selection may favor parents producing offspring with varying levels of plasticity. The current article presents a mathematical model assessing the logic of this hypothesis – specifically, it examines what conditions are required for natural selection to favor parents to bet-hedge by varying their offspring's plasticity. Consistent with existing theory from biology, results show that between-individual variation in plasticity cannot evolve when the environment only varies across space. If, however, the environment varies across time, selection can favor differential plasticity, provided fitness effects are large (i.e. variation in individuals’ plasticity is correlated with substantial variation in fitness). Our model also generates a novel restriction: Differential plasticity only evolves when the cost of being mismatched to the environment exceeds the benefits of being well matched. Based on mechanistic considerations, we argue that bet-hedging by varying offspring plasticity, if it were to evolve, would be more likely instantiated via epigenetic mechanisms (e.g. pre- or postnatal developmental programming) than genetic ones (e.g. mating with genetically diverse partners). Our model suggests novel avenues for testing the bet-hedging hypothesis of differential plasticity, including empirical predictions and relevant measures. We also discuss several ways in which future work might extend our model. 24 p.

Contains fulltext : 149507.pdf (Publisher’s version ) (Open Access) Development in many organisms appears to show evidence of sensitive windows—periods or stages in ontogeny in which individual experience has a particularly strong influence on the phenotype (compared to other periods or stages). Despite great interest in sensitive windows from both fundamental and applied perspectives, the functional (adaptive) reasons why they have evolved are unclear. Here we outline a conceptual framework for understanding when natural selection should favour changes in plasticity across development. Our approach builds on previous theory on the evolution of phenotypic plasticity, which relates individual and population differences in plasticity to two factors: the degree of uncertainty about the environmental conditions and the extent to which experiences during development (‘cues’) provide information about those conditions. We argue that systematic variation in these two factors often occurs within the lifetime of a single individual, which will select for developmental changes in plasticity. Of central importance is how informational properties of the environment interact with the life history of the organism. Phenotypes may be more or less sensitive to environmental cues at different points in development because of systematic changes in (i) the frequency of cues, (ii) the informativeness of cues, (iii) the fitness benefits of information and/or (iv) the constraints on plasticity. In relatively stable environments, a sensible null expectation is that plasticity will gradually decline with age as the developing individual gathers information. We review recent models on the evolution of developmental changes in plasticity and explain how they fit into our conceptual framework. Our aim is to encourage an adaptive perspective on sensitive windows in development. 14 p.

Many recent evolutionary psychology and human behavioral ecology studies have tested hypotheses by examining correlations between variables measured at a group level (e.g., state, country, continent). In such analyses, variables collected for each aggregation are often taken to be representative of the individuals present within them, and relationships between such variables are presumed to reflect individual-level processes. There are multiple reasons to exercise caution when doing so, including: (1) the ecological fallacy, whereby relationships observed at the aggregate level do not accurately represent individual-level processes; (2) non-independence of data points, which violates assumptions of the inferential techniques used in null hypothesis testing; and (3) cross-cultural non-equivalence of measurement (differences in construct validity between groups). We provide examples of how each of these gives rise to problems in the context of testing evolutionary hypotheses about human behavior, and we offer some suggestions for future research. © 2014 Springer Science+Business Media New York.

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.

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.