Evolutionary-developmental Theory Research Articles

Death from Failed Protection? An Evolutionary-Developmental Theory of Sudden Infant Death Syndrome

Sudden infant death syndrome (SIDS) has been mainly described from a risk perspective, with a focus on endogenous, exogenous, and temporal risk factors that can interact to facilitate lethal outcomes. Here we discuss the limitations that this risk-based paradigm may have, using two of the major risk factors for SIDS, prone sleep position and bed-sharing, as examples. Based on a multipronged theoretical model encompassing evolutionary theory, developmental biology, and cultural mismatch theory, we conceptualize the vulnerability to SIDS as an imbalance between current physiologic-regulatory demands and current protective abilities on the part of the infant. From this understanding, SIDS appears as a developmental condition in which competencies relevant to self-protection fail to develop appropriately in the future victims. Since all of the protective resources in question are bound to emerge during normal infant development, we contend that SIDS may reflect an evolutionary mismatch situation—a constellation in which certain modern developmental influences may overextend the child’s adaptive (evolutionary) repertoire. We thus argue that SIDS may be better understood if the focus on risk factors is complemented by a deeper appreciation of the protective resources that human infants acquire during their normal development. We extensively analyze this evolutionary-developmental theory against the body of epidemiological and experimental evidence in SIDS research and thereby also address the as-of-yet unresolved question of why breastfeeding may be protective against SIDS.

Stress, mental health and sociocultural adjustment in third culture kids: exploring the mediating roles of resilience and family functioning.

This cross-sectional study explores the contributions of personal and contextual factors in the adjustment process of a sample of internationally mobile children and adolescents having relocated to Switzerland. Based on evolutionary developmental theories and recommendations by Research Domain Criteria and The Hierarchical Taxonomy of Psychopathology theoretical frameworks, we hypothesized and tested a heuristic model of TCK adjustment, aiming to identify prevention and treatment targets tailored for our sampled population. We assessed the relationships in the hypothesized models, particularly how perceived and acculturative stress influence TCK adjustment and whether the relationship between the predictors of TCK stress and the outcomes of TCK adjustment are mediated by resilience and family functioning. A total of 143 participants aged 7-17, having relocated internationally with their working parent(s), recruited in local and international schools in Switzerland, were included in this study. Data were collected using an online survey after we collected consent. We assessed factors of adjustment using validated questionnaires: perceived stress and acculturative stress and the potential mediating roles of family functioning and resilience. We measured the outcome of adjustment through mental health difficulties and sociocultural adjustment. We used path analysis to test the model. Results highlight the contributions of perceived stress and acculturative stress to TCK mental health and sociocultural adjustment. We also we found a mediation effect for resilience in the relationship between perceived stress and mental health. Family functioning was not a significant mediator in any relationship that we assessed. We discuss implications for future research, promoting TCK adjustment and preventative psychotherapeutic interventions.

Considering Evolutionary Developmental Theory in the Developmental Model of the Sexual Minority Closet.

Considering Evolutionary Developmental Theory in the Developmental Model of the Sexual Minority Closet.

Developmental risk sensitivity theory: the effects of socio-economic status on children's risky gain and loss decisions.

Evolutionary developmental theories propose that early environments shape human risk preferences. Developmental risk sensitivity theory (D-RST) focuses on the plasticity of risk preferences during childhood and makes predictions about the effect of reward size based on a child's social environment. By contrast, prospect theory predicts risk aversion for gains and risk seeking for losses regardless of environment or status. We presented 4 to 10-year-olds (n = 194) with a set of trials in which they chose between a certain amount and a chance to receive more or nothing. Two trials were equal expected value choices that differed by stake size and two were unequal expected value choices. Children either received gain trials or loss trials. Social environment was assessed using socio-economic status (SES) and subjective social status. Results confirmed the predictions of D-RST for gains based on SES. Children from lower-SES families differentiated between the high- and low-value trials and made more risky decisions for the high-value reward compared with higher-SES children. Children from higher-SES families were more risk averse for both trial types. Decisions for loss trials did not conform completely to either theory. We discuss the results in relation to evolutionary developmental theories.

A Meta-Analysis of the "Erasing Race" Effect in the United States and Some Theoretical Considerations.

The “erasing race” effect is the reduction of the salience of “race” as an alliance cue when recalling coalition membership, once more accurate information about coalition structure is presented. We conducted a random-effects model meta-analysis of this effect using five United States studies (containing nine independent effect sizes). The effect was found (ρ = 0.137, K = 9, 95% CI = 0.085 to 0.188). However, no decline effect or moderation effects were found (a “decline effect” in this context would be a decrease in the effect size over time). Furthermore, we found little evidence of publication bias. Synthetically correcting the effect size for bias stemming from the use of an older method for calculating error base rates reduced the magnitude of the effect, but the it remained significant. Taken together, these findings indicate that the “erasing race” effect generalizes quite well across experimental contexts and would, therefore, appear to be quite robust. We reinterpret the theoretical basis for these effects in line with Brunswikian evolutionary-developmental theory and present a series of predictions to guide future research in this area.

Potential for Resting-State fMRI of the Amygdala in Elucidating Neural Mechanisms of Adaptive Self-Regulatory Strategies: A Systematic Review.

Evolutionary-developmental theories consider the evolved mechanisms underlying adaptive behavioral strategies shaped in response to early environmental cues. Identifying neural mechanisms mediating processes of conditional adaptation in humans is an active area of research. Resting-state functional magnetic resonance imaging (RS-fMRI) captures functional connectivity theorized to represent the underlying functional architecture of the brain. This allows for investigating how underlying functional brain connections are related to early experiences during development, as well as current traits and behaviors. This review explores the potential of RS-fMRI of the amygdala (AMY) for advancing research on the neural mechanisms underlying adaptive strategies developed in early adverse environments. RS-fMRI studies of early life stress (ELS) and AMY functional connectivity within the frame of evolutionary theories are reviewed, specifically regarding the development of self-regulatory strategies. The potential of RS-fMRI for investigating the effects of ELS on developmental trajectories of self-regulation is discussed.

Can an unpredictable childhood environment enhance working memory? Testing the sensitized-specialization hypothesis.

Although growing up in an adverse childhood environment tends to impair cognitive functions, evolutionary-developmental theory suggests that this might be only one part of the story. A person's mind may instead become developmentally specialized and potentially enhanced for solving problems in the types of environments in which the person grew up. In the current research, we tested whether these specialized advantages in cognitive function might be sensitized to emerge in currently uncertain contexts. We refer to this as the sensitized-specialization hypothesis. We conducted experimental tests of this hypothesis in the domain of working memory, examining how growing up in unpredictable versus predictable environments affects different facets of working memory. Although growing up in an unpredictable environment is typically associated with impairments in working memory, we show that this type of environment is positively associated with those aspects of working memory that are useful in rapidly changing environments. Importantly, these effects emerged only when the current context was uncertain. These theoretically derived findings suggest that childhood environments shape, rather than uniformly impair, cognitive functions. (PsycINFO Database Record

Biological stress regulation in female adolescents: a key role for confiding.

Attachment behaviors play a critical role in regulating emotion within the context of close relationships, and attachment theory is currently used to inform evidence-based practice in the areas of adolescent health and social care. This study investigated the association between female adolescents' interview-based attachment behaviors and two markers of hypothalamic-pituitary-adrenal axis activity: cortisol and dehydroepiandrosterone (DHEA). Unlike the classic stress hormone cortisol, there is very limited investigation of DHEA-a quintessential developmental hormone-in relation to attachment, especially in adolescents. Fifty-five healthy females mean age 14.36 (±2.41) years participated in the attachment style interview. A smaller cortisol awakening response was related to anxious attachment attitudes, including more fear of rejection, whereas greater morning basal DHEA secretion was only predicted by lower levels of reported confiding in one's mother. These attachment-hormone relationships may be developmental markers in females, as they were independent of menarche status. These findings highlight that the normative shifts occurring in attachment to caregivers around adolescence are reflected in adolescents' biological stress regulation. We discuss how studying these shifts can be informed by evolutionary-developmental theory.

An Evolutionary Developmental Approach to Cultural Evolution

Evolutionary developmental theories in biology see the processes and organization of organisms as crucial for understanding the dynamic behavior of organic evolution. Darwinian forces are seen as necessary but not sufficient for explaining observed evolutionary patterns. We here propose that the same arguments apply with even greater force to culture vis-à-vis cultural evolution. In order not to argue entirely in the abstract, we demonstrate the proposed approach by combining a set of different models into a provisional synthetic theory and by applying this theory to a number of short case studies. What emerges is a set of concepts and models that allow us to consider entirely new types of explanations for the evolution of cultures. For example, we see how feedback relations--both within societies and between societies and their ecological environment--have the power to shape evolutionary history in profound ways. The ambition here is not to produce a definitive statement on what such a theory should look like but rather to propose a starting point along with an argumentation and demonstration of its potential.

Beyond allostatic load: Rethinking the role of stress in regulating human development

How do exposures to stress affect biobehavioral development and, through it, psychiatric and biomedical disorder? In the health sciences, the allostatic load model provides a widely accepted answer to this question: stress responses, while essential for survival, have negative long-term effects that promote illness. Thus, the benefits of mounting repeated biological responses to threat are traded off against costs to mental and physical health. The adaptive calibration model, an evolutionary-developmental theory of stress-health relations, extends this logic by conceptualizing these trade-offs as decision nodes in allocation of resources. Each decision node influences the next in a chain of resource allocations that become instantiated in the regulatory parameters of stress response systems. Over development, these parameters filter and embed information about key dimensions of environmental stress and support, mediating the organism's openness to environmental inputs, and function to regulate life history strategies to match those dimensions. Drawing on the adaptive calibration model, we propose that consideration of biological fitness trade-offs, as delineated by life history theory, is needed to more fully explain the complex relations between developmental exposures to stress, stress responsivity, behavioral strategies, and health. We conclude that the adaptive calibration model and allostatic load model are only partially complementary and, in some cases, support different approaches to intervention. In the long run, the field may be better served by a model informed by life history theory that addresses the adaptive role of stress response systems in regulating alternative developmental pathways.

Adaptive calibration of children's physiological responses to family stress: The utility of evolutionary developmental theory: Comment on Del Giudice et al. (2012) and Sturge-Apple et al. (2012).

Children's physiological reactions to stress are presented from the broader theoretical perspective of adaptive calibration to the environment, as rooted in life history theory. Del Giudice, Hinnant, Ellis, and El-Sheikh (2012) focus on children's physiological responses to a stressful task as a consequence of their history of family stress. Sturge-Apple, Davies, Martin, Cicchetti, and Hentges (2012) focus on the ways that children respond to a novel laboratory manipulation as a combined function of their temperament patterns and the harshness of their parental environment. The theoretical perspective employed provides an overarching framework that not only accounts for the findings presented here but also has heuristic value for future research on responses to early environmental risk. Future work in this area will benefit by inclusion of additional sympathetic nervous system (SNS) markers and neurotransmitters, inclusion of the role of gene expression in adaptive calibration, broader consideration of protective factors in the child's environment, and longitudinal work demonstrating the effects of adaptive calibration on children's future life history strategies and outcomes.

Sex-specific pathways to early puberty, sexual debut, and sexual risk taking: Tests of an integrated evolutionary–developmental model.

The current study tested sex-specific pathways to early puberty, sexual debut, and sexual risk taking, as specified by an integrated evolutionary-developmental model of adolescent sexual development and behavior. In a prospective study of 238 adolescents (n = 129 girls and n = 109 boys) followed from approximately 12-18 years of age, we tested for longitudinal relations between ecological stressors, family relationships, pubertal maturation, self-perceived mate value, and sexual risk taking in both boys and girls. Consistent with the theory, (a) higher levels of familial and ecological stress predicted earlier sexual debut and greater sexual risk taking; (b) pubertal maturation partially mediated these relations among girls but not among boys; (c) father absence had unique effects on female sexual outcomes but not on male sexual outcomes; (d) higher self-perceived mate value directly predicted earlier sexual debut and, through it, greater sexual risk taking; and (e) relations between pubertal maturation and early sexual debut were partially mediated by higher self-perceived mate value in boys but not in girls. Discussion focuses on the contribution of an integrated evolutionary-developmental theory to the adolescent sexual health literature.

Beyond mental health: An evolutionary analysis of development under risky and supportive environmental conditions: An introduction to the special section.

Evolutionary approaches to behavior have increasingly captured the attention and imagination of academics and laypeople alike. One part of this trend has been the increasing influence of evolutionary theory in developmental science. The articles in this special section of Developmental Psychology attempt to demonstrate why an evolutionary analysis is needed to more fully understand the contexts and contingencies of development. The 3 theoretical articles articulate the core evolutionary logic underlying conditional adaptation (and maladaptation) to both stressful and supportive environmental conditions over development. These theoretical articles are then followed by 9 empirical articles that test these evolutionary-developmental theories and hypotheses. Finally, 6 commentaries evaluate the prospects, pitfalls, and implications of this body of work.

Adaptive patterns of stress responsivity: A preliminary investigation.

The adaptive calibration model (ACM) is an evolutionary-developmental theory of individual differences in stress responsivity. In this article, we tested some key predictions of the ACM in a middle childhood sample (N = 256). Measures of autonomic nervous system activity across the sympathetic and parasympathetic branches validated the 4-pattern taxonomy of the ACM via finite mixture modeling. Moreover, the 4 patterns of responsivity showed the predicted associations with family stress levels but no association with measures of ecological stress. Our hypotheses concerning sex differences in responsivity were only partly confirmed. This preliminary study provides initial support for the key predictions of the ACM and highlights some of the methodological challenges that will need to be considered in future research on this topic.

Quality of early family relationships and the timing and tempo of puberty: effects depend on biological sensitivity to context.

Guided by evolutionary-developmental theories of biological sensitivity to context and reproductive development, the current research examined the interactive effects of early family environments and psychobiologic reactivity to stress on the subsequent timing and tempo of puberty. As predicted by the theory, among children displaying heightened biological sensitivity to context (i.e., higher stress reactivity), higher quality parent-child relationships forecast slower initial pubertal tempo and later pubertal timing, whereas lower quality parent-child relationships forecast the opposite pattern. No such effects emerged among less context-sensitive children. Whereas sympathetic nervous system reactivity moderated the effects of parent-child relationships on both breast/genital and pubic hair development, adrenocortical activation only moderated the effect on pubic hair development. The current results build on previous research documenting what family contexts predict variation in pubertal timing by demonstrating for whom those contexts matter. In addition, the authors advance a new methodological approach for assessing pubertal tempo using piecewise growth curve analysis.

The importance of ontogenetic change in typical and atypical development

AbstractThe compelling case that Anderson makes for neural reuse and against modularity as organizing principle of the brain is further supported by evidence from developmental disorders. However, to provide a full evolutionary-developmental theory of neural reuse that encompasses both typical and atypical development, Anderson's “massive redeployment hypothesis” (MRH) could be further constrained by considering brain development across ontogeny.

Prenatal cocaine exposure and infant cortisol reactivity.

This study examined the effects of prenatal cocaine exposure on infant hypothalamic-pituitary-adrenal axis activity and reactivity at 7 months of infant age. Participants were 168 caregiver-infant dyads (87 cocaine exposed, 81 not cocaine exposed; 47% boys). Maternal behavior, caregiving instability, and infant growth and behavior were assessed, and children's saliva was sampled before, during, and after standardized procedures designed to elicit emotional arousal. Results revealed cocaine-exposed infants had a high amplitude trajectory of cortisol reactivity compared to non-cocaine-exposed infants. Infant gender and caregiving instability moderated this association. The findings support a dual hazard vulnerability model and have implications for evolutionary-developmental theories of individual differences in biological sensitivity to context.

A Brunswikian evolutionary developmental theory of preparedness and plasticity

The domain-independent and domain-dependent approach to the evolution of cognition have been taken by separate groups of researchers who have focused exclusively on either the formal properties or the distinct cognitive demands of tasks. We express the view that synthesizing the two approaches could lead to a more complete understanding, and propose such a comprehensive model of cognitive evolution and development. First, we discuss how Egon Brunswik demonstrated the importance of the relationship between the organism and the environment, and how his research and that of others has led to the domain-independent and domain-dependent views. Second, we use Brunswikian concepts to propose a two-parameter evolutionary model of cognitive development that specifies how particular behaviors come to be characterized by independent levels of biological preparedness and developmental plasticity. Our theory incorporates both a domain-independent organizing principle and the importance of domain-dependent processes. Third, we briefly discuss one unique prediction arising from the Brunswikian Evolutionary Developmental theory and describe preliminary supporting evidence.

Biological sensitivity to context: II. Empirical explorations of an evolutionary–developmental theory

In two studies comprising 249 children and their families, the authors utilized secondary, exploratory data analyses to examine Boyce and Ellis' (this issue) evolutionary-developmental theory of biological sensitivity to context. The theory proposes that individual differences in stress reactivity constitute variation in susceptibility to environmental influence, both positive and negative, and that early childhood exposures to either highly protective or acutely stressful environments result in heightened reactivity. In Study 1, 127 3- to 5-year old children were concurrently assessed on levels of support/adversity in home and preschool environments and on cardiovascular reactivity to laboratory challenges. In Study 2, 122 children were prospectively assessed on familial stress in both infancy and preschool and on autonomic and adrenocortical reactivity to laboratory challenges at age 7. In both studies, a disproportionate number of children in supportive, low stress environments displayed high autonomic reactivity. Conversely, in Study 2, a relatively high proportion of children in very stressful environments showed evidence of heightened sympathetic and adrenocortical reactivity. Consistent with the evolutionary-developmental theory, the exploratory analyses also generated the testable hypothesis that relations between levels of childhood support/adversity and the magnitude of stress reactivity are curvilinear, with children from moderately stressful environments displaying the lowest reactivity levels in both studies.

Biological sensitivity to context: I. An evolutionary–developmental theory of the origins and functions of stress reactivity

Biological reactivity to psychological stressors comprises a complex, integrated, and highly conserved repertoire of central neural and peripheral neuroendocrine responses designed to prepare the organism for challenge or threat. Developmental experience plays a role, along with heritable, polygenic variation, in calibrating the response dynamics of these systems, with early adversity biasing their combined effects toward a profile of heightened or prolonged reactivity. Conventional views of such high reactivity suggest that it is an atavistic and pathogenic legacy of an evolutionary past in which threats to survival were more prevalent and severe. Recent evidence, however, indicates that (a) stress reactivity is not a unitary process, but rather incorporates counterregulatory circuits serving to modify or temper physiological arousal, and (b) the effects of high reactivity phenotypes on psychiatric and biomedical outcomes are bivalent, rather than univalent, in character, exerting both risk-augmenting and risk-protective effects in a context-dependent manner. These observations suggest that heightened stress reactivity may reflect, not simply exaggerated arousal under challenge, but rather an increased biological sensitivity to context, with potential for negative health effects under conditions of adversity and positive effects under conditions of support and protection. From an evolutionary perspective, the developmental plasticity of the stress response systems, along with their structured, context-dependent effects, suggests that these systems may constitute conditional adaptations: evolved psychobiological mechanisms that monitor specific features of childhood environments as a basis for calibrating the development of stress response systems to adaptively match those environments. Taken together, these theoretical perspectives generate a novel hypothesis: that there is a curvilinear, U-shaped relation between early exposures to adversity and the development of stress-reactive profiles, with high reactivity phenotypes disproportionately emerging within both highly stressful and highly protected early social environments.