The Developmental Functions of Emotions: An Analysis in Terms of Differential Emotions Theory

A substantial body of theoretical literature testifies to the evolutionary functions of emotions. Relatively little has been written about their developmental functions. This article discusses the developmental functions of emotions from the perspective of differential emotions theory (DET; Izard, 1977, 1991). According to DET, although all the emotions retain their adaptive and motivational functions across the lifespan, different sets of emotions may become relatively more prominent in the different stages of life as they serve stage-related developmental processes. In the first section, we present a brief overview of relevant aspects of the theory. In the second section, we discuss how emotions play a central role in helping the individual achieve developmental milestones and tasks during four major periods of life: Infancy, toddler through preschool years, middle to late childhood, and adolescence. The underlying thesis of this article is that emotions play a central role in stimulating social cognitive attainments at each stage of development.     

A preregistered study of the relationship between childhood socioeconomic background,life history strategies and conformity

We conducted a high powered pre-registered study to investigate the relationship between childhood socioeconomic status, the adoption of different life history strategies and conformity. Contrary to our expectation we found no direct relationship between childhood socioeconomic background and conformity. However, we discovered a significant association between life history strategies and conformity. People who adopt fast (slow) life history strategies conform less (more) to social suggestions. Furthermore, we found a relationship between childhood socioeconomic background and life history strategies, with people from low (high) childhood socioeconomic backgrounds adopting fast (slow) life history strategies.     

进化发展心理学：发展中的人类本性

进化发展心理学研究社会能力与认知能力发展背后的基因与环境机制,以及基因与环境机制在特定社会文化中的表现。进化发展心理学探讨的主要问题与设计到的主要概念包括：（1）自然选择在毕生发展的早期阶段发挥作用;（2）进化发展心理学特别重视适应在婴儿期及儿童期发展中的作用;（3）儿童期的延长有助于儿童学习人类社会的复杂性;（4）发展背景的方法可以用来理解成人外显行为的进化起源;（5）基因与环境因素相互影响约束个体发展;（6）认知能力与行为活动敏感于早期环境,但二者发展也具有可塑性     

Children,childhood, and development in evolutionary perspective

We examine children, childhood, and development from an evolutionary perspective. We begin by reviewing major assumptions of evolutionary–developmental psychology, including the integration of “soft” developmental systems theory with ideas from mainstream evolutionary psychology. We then discuss the concept of adaptive developmental plasticity and describe the core evolutionary concept of developmental programming and some of its applications to human development, as instantiated in life history theory and the theory of differential susceptibility to environmental influence. We then discuss the concept of adaptation from an evolutionary–developmental perspective, including ontogenetic and deferred adaptations, and examine the development of some adaptations of infancy and childhood from the domains of folk psychology and folk physics. We conclude that evolutionary theory can serve as a metatheory for developmental science.     

Language and life history: a new perspective on the development and evolution of human language

It has long been claimed that Homo sapiens is the only species that has language, but only recently has it been recognized that humans also have an unusual pattern of growth and development. Social mammals have two stages of pre-adult development: infancy and juvenility. Humans have two additional prolonged and pronounced life history stages: childhood, an interval of four years extending between infancy and the juvenile period that follows, and adolescence, a stage of about eight years that stretches from juvenility to adulthood. We begin by reviewing the primary biological and linguistic changes occurring in each of the four pre-adult ontogenetic stages in human life history. Then we attempt to trace the evolution of childhood and juvenility in our hominin ancestors. We propose that several different forms of selection applied in infancy and childhood; and that, in adolescence, elaborated vocal behaviors played a role in courtship and intrasexual competition, enhancing fitness and ultimately integrating performative and pragmatic skills with linguistic knowledge in a broad faculty of language. A theoretical consequence of our proposal is that fossil evidence of the uniquely human stages may be used, with other findings, to date the emergence of language. If important aspects of language cannot appear until sexual maturity, as we propose, then a second consequence is that the development of language requires the whole of modern human ontogeny. Our life history model thus offers new ways of investigating, and thinking about, the evolution, development, and ultimately the nature of human language.     

Differential K theory: The sociobiology of individual and group differences

Differential K Theory is proposed to help systematize individual and group differences in life histories, social behaviour and physiological functioning. K refers to one end of a continuum of reproductive strategies organisms can adopt, characterized by the production of very few offspring with a large investment of energy in each. At the opposite extreme is the r-strategy in which organisms produce a large number of offspring but invest little energy in any one. Between-species comparisons demonstrate that these reproductive strategies correlate with a variety of life history traits including: litter size, birth-spacing, parental care, infant mortality, developmental precocity, life span, intelligence, social organization and altruism. As a species, humans are at the K end of the continuum. Some people, however, are postulated to be more K than others. The more K a person is, the more likely he or she is to come from a smaller sized family, with a greater spacing of births, a lower incidence of DZ twinning, and more intensive parental care. Moreover, he or she will tend to be intelligent, altruistic, law-abiding, behaviourally restrained, maturationally delayed, lower in sex drive and longer lived. Thus diverse organismic characteristics, not otherwise relatable, are presumed to covary along the K dimension. Group differences are also hypothesized, such that, in terms of K: higher socio-economic > lower socio-economic; and Mongoloids > Caucasoids > Negroids.     

A life history assessment of early childhood sexual abuse in women

Life history theory provided a framework for examining the relations among child sexual abuse (CSA), childhood adversity, and patterns of reproductive development and behavior. A community survey that assessed CSA, life history variables (e.g., age of menarche), and social and family background was administered to 623 women (mean age=26.9 years). Independent of social and family background, CSA was associated with earlier age of (a) menarche, (b) first sexual relationship, (c) desire to have children, (d) first childbirth, and (e) lower self-evaluated physical attractiveness. Cluster analyses revealed different patterns of experiential correlates of reproductive development within the group of abused women, suggesting CSA may operate in combination with other childhood circumstances to modify the timing and pattern of individual maturation.     

Play,Precariousness, and the Negotiation of Shared Meaning: A Developmental Research Perspective on Child Psychotherapy

Recent work in developmental psychology and primatology indicates that human infants are distinguished from other primates by the end of the 1st year by their awareness that others have subjective states like their own. This early appearing awareness of the subjectivity of others forms the basis for the subsequent negotiation and elaboration of “we-ness,” that is, of shared orientations toward the world that allow the child to enter into collaborative relations with others. It is argued that this gradual working out of collaborative strategies for the elaboration of shared meanings is a principal function of joint pretend play in early childhood, and this is one of the critical developmental functions addressed in psychodynamic play therapy. Developmental theory and research contributing to this perspective is integrated with excerpts from children's joint pretend play and from play therapy case material to illustrate the precarious and improvisational nature of the negotiation of shared meaning.     

The K-factor: Individual differences in life history strategy

Until recently, variations in life history strategy were studied exclusively at the species level. Although this domain of study has been extended to examine systematic differences in life history strategy among various human ethnic groupings, more recent evolutionary theories of human development and related behavioral genetic work imply substantial within-group individual variation in life history strategy. We constructed a latent variable model identifying a single common factor, denoted as K, which underlies a variety of otherwise disparate life history parameters. This “K-Factor” loaded 0.36 on childhood attachment to the biological father, −0.36 on childhood attachment to any non-biological father figure, 0.38 on adult romantic partner attachment, −0.51 on mating effort, −0.58 on Machiavellianism, and −0.41 on risk propensity. The bivariate correlations of the K-factor with higher-order personality factors were statistically significant, −0.24 with “Big Neuroticism” and −0.67 with “Big Psychoticism”, and approached significance, correlating 0.12, with “Big Extraversion”. The K-factor appears to be an underappreciated individual difference variable of major importance to human development.     

Participatory Action Research (PAR) in Middle School: Opportunities, Constraints, and Key Processes

Late childhood and early adolescence represent a critical transition in the developmental and academic trajectory of youth, a time in which there is an upsurge in academic disengagement and psychopathology. PAR projects that can promote youth's sense of meaningful engagement in school and a sense of efficacy and mattering can be particularly powerful given the challenges of this developmental stage. In the present study, we draw on data from our own collaborative implementation of PAR projects in secondary schools to consider two central questions: (1) How do features of middle school settings and the developmental characteristics of the youth promote or inhibit the processes, outcomes, and sustainability of the PAR endeavor? and (2) How can the broad principles and concepts of PAR be effectively translated into specific intervention activities in schools, both within and outside of the classroom? In particular, we discuss a participatory research project conducted with 6th and 7th graders at an urban middle school as a means of highlighting the opportunities, constraints, and lessons learned in our efforts to contribute to the high‐quality implementation and evaluation of PAR in diverse urban public schools.     

Match fitness: development, evolution, and behavior: comment on Frankenhuis and Del Giudice (2012)

The application of evolutionary thinking to human physical and psychological medicine suggests several pathways through which evolutionary processes affect risk of disease. Among these is the concept of mismatch between an individual and its environment, either because the environment has changed for the whole species (evolutionary novelty) or because the environment has changed for an individual during its lifetime (developmental mismatch). Here we set a discussion of maladaptation and mismatch as a cause of psychopathology (Frankenhuis & Del Giudice, 2012) in the broader framework of developmental plasticity and life history trade-offs.     

早期经验对繁衍策略形成与发展的影响

很多发展心理学家探讨了早期经验与心理行为发展的关系,但这些发展心理学家较少以进化理论为指导来探讨不同发展阶段的心理行为特点。比如,配偶选择、性交往与父母教养等成果颇丰的研究领域均缺少以进化理论为基础的理论解释。与主流的发展心理学研究不同,Draper和Harpending (1982),Ellis (2004),Chisholm (1996) 和Belsky等(1991)以进化理论为基础探讨了早期经验与繁衍策略对儿童心理行为发展的影响。进化观点认为儿童在家庭中获得的早期经验会影响身体发育与未来的繁衍策略。Ellis（2004）已经证实女性青春期确实与早期家庭经验有关     

生命早期环境不可预测性对过度进食的影响:基于生命史理论

在生命史理论的视角下, 本研究通过两个研究揭示了生命早期环境不可预测性对过度进食的影响及其作用机制。研究1招募处于生命早期阶段的91名初中生(年龄12~14岁), 采用饱食进食(Eating in the absence of hunger, EAH)范式, 结果发现生命早期环境不可预测性能够显著正向预测个体饱食状态下的高热量食物选择(即过度进食); 研究2招募新冠病毒疾病(COVID-19)暴发背景下301名武汉市居民(高死亡威胁组)和179名其他省市居民(控制组) (年龄18~60岁)为被试, 通过问卷法回溯性地测量生命早期环境不可预测性并探究其影响当前过度进食的机制, 结果发现生命早期环境不可预测性通过生命史策略的中介作用间接影响过度进食。同时, 死亡威胁(新冠病毒疫情)扩大了环境不可预测性通过生命史策略间接影响过度进食的效应, 而社会支持则能缓冲这一效应。研究结果为COVID-19背景下和灾后居民的健康进食干预提供了依据。     

Children's understanding of the pretence–reality distinction: a review of current theory and evidence

This paper provides an update on the current status of theory and evidence relating to children's understanding of the pretence–reality distinction. The paper starts by highlighting the striking paradox between children's early competence in pretence and their experiences of pretence–reality confusions as late as middle childhood. This is followed by a detailed review of various theories that have been offered to explain this phenomenon. Specifically, theories attributing the paradoxical findings to methodological differences between studies are reviewed and dismissed before considering the transmigration and availability hypotheses ( Harris, Brown, Marriott, Whittall & Harmer, 1991 ; Johnson & Harris, 1994 ), the role of context and the child's emotional involvement in the pretence, and the pretence continuation account ( Golomb & Galasso, 1995 ). It is argued that none of these theories alone can explain pretence–reality confusions and that these are best explained in terms of the combined influences of cognitive availability, empirical evidence of reality, context, affect and individual differences. Further research is necessary to fully explore the nature, cause and developmental trajectory of individual differences in this domain.     

Child well-being in an era of welfare reform: the sensitivity of transitions in development to policy change

This study examined the age-specific pattern of effects of welfare policies on child achievement. Drawing from 7 random-assignment welfare and antipoverty evaluations that provided more than 30,000 observations of children's achievement, this study found that times of developmental transition are the only periods sensitive to the changes in families brought about by these policies. More specifically, small positive effects of welfare and antipoverty policies were found for children making the transition into middle childhood, and small negative effects of these same policies were found for children making the transition out of middle childhood and into early adolescence. Effects were robust across various program groupings and could not be attributed to family characteristics that differ for children of different ages. This research informs the understanding of how changes in employment and income for low-income parents affect development across childhood.     

Links Between Life Course Trajectories of Family Dysfunction and Anxiety During Middle Childhood

Using data from three waves of a large Canadian data set, we examine the relationship between two middle childhood trajectory variables, family dysfunction and anxiety. We draw upon family systems theory and developmental psychopathology, while attempting to expand their boundaries by capitalizing on the strengths within both approaches. Our data treatment strategy, guided by the life course analytical framework, included separate multivariate logits to examine this relationship, with and without the extent to, which selected explanatory risk variables predicted belonging to the highest family dysfunction trajectory. We also explored possible interactions between anxiety and explanatory risk variables. Supporting our hypothesis, a prolonged duration of high doses of family dysfunction was associated with the most extreme developmental trajectories of anxious behavior during middle childhood for both boys and girls. This relationship prevailed above and beyond the influence of other correlates of family dysfunction such as marital transition, socioeconomic status, family size, and depressive symptoms experienced by the informant (mostly mothers). Specific details regarding the sample, characteristics of measures, and unspecified estimates and their standard errors per data source are available from the first author in the form of tables and figures.     

Childhood and advances in human tool use

Human life history incorporates childhood, a lengthy post-weaning period of dependency. This species-specific period provides an opportunity for extensive learning and for sophisticated cultural behaviors to develop, including crucial tool use skills. Although I agree that no individual cognitive trait singularly differentiates humans from other animals, I suggest here that without childhood, the traits that are key to human tool use would not emerge.     

Visual habituation in human infants: development and rearing circumstances

Summary Habituation is a type of learning that reflects changing responsiveness to repeated information. In two longitudinal studies, we examined individual differences, stability, and developmental change in the ontogeny of visual habituation in human infants across the middle of the first year of life. To study this phenomenon in breadth, we tested infants from two social classes within the same culture and infants from two different cultures. Infants demonstrated significant, but comparable, individual differences in habituation across socioeconomic and cultural variations in rearing circumstances; they showed significant, if moderate, stability in habituation; and they habituated significantly more quickly with age. These results are interpreted in terms of developing human beings' increasing efficiency in processing visual information near the beginning of extrauterine life.     

Sex steroids and human behavior: implications for developmental psychopathology

In a variety of mammalian species, prenatal androgens organize brain structures and functions that are later activated by steroid hormones in postnatal life. In humans, studies of individuals with typical and atypical development suggest that sex differences in reproductive and nonreproductive behavior derive in part from similar prenatal and postnatal steroid effects on brain development. This paper provides a summary of research investigating hormonal influences on human behavior and describes how sex differences in the prevalences and natural histories of developmental psychopathologies may be consistent with these steroid effects. An association between patterns of sexual differentiation and specific forms of psychopathology suggests novel avenues for assessing the effects of sex steroids on brain structure and function, which may in turn improve our understanding of typical and atypical development in women and men.     

Importance of developmental theory and investigation to research in clinical child psychology

Focuses on the developmental periods of infancy, childhood, and adolescence to offer illustrations of the advantages of using developmental theory and research to establish targets for research on intervention, assessment and treatment planning, and evaluation of effective strategies for prevention of childhood and later adult disorders. The importance for training clinical graduate students in developmental approaches to research is stressed, and hopes for a future of mutual contributions of developmental and clinical psychology are expressed in light of the fact that, after a troubled history of isolation from one another and even active denigration of one another's goals and methods, developmental and clinical psychology are exhibiting joint recognition of the advantages of collaborative research.