António J. Santos

Ethological research traditions consistently provided valuable insights that have informed many child development conceptual frameworks and programs, evidently not without some limitations and challenges in effective translation into real-world interventions. Despite these challenges, the core principles from ethological research remain highly valuable and continue to inspire innovative approaches to supporting research on child social development. Addressing these limitations through interdisciplinary collaboration, rigorous evaluation, and contextual adaptation can help unlock the full potential of ethological contributions. Such an approach should provide a solid foundation for exploring the intersectional hallmarks of ethological research on developmental psychology, particularly in the areas of parenting and peer relations. Overall, the original fields of primate and child ethology have continued to evolve, leveraging technological and theoretical advancements to deepen our understanding of the complex interplay between biology, social bonding, and social development. The methodological sophistication and expanded scope of contemporary research offer valuable insights for informing real-world applications on supporting healthy social-emotional development and improving therapy conditions outcomes for children, families, and communities.

The increase in women’s labor market participation emphasizes the importance of understanding maternal separation anxiety, that is, the unpleasant maternal emotional state, due to the actual or anticipated short-term separation from the child. Drawing on the insights of the attachment and psychoanalytic perspectives, the Maternal Separation Anxiety Scale was developed to overcome existing measurement gaps. However, prior research did not replicate its original three-factor structure in the contemporary context and in other cultural settings, using large samples composed of mothers of preschool children. This study aimed to examine the factorial structure of the MSAS in a sample of 597 Portuguese mothers of children aged 5–84 months who completed the questionnaire. The exploratory factor analysis conducted in subsample 1 revealed a four-factor structure: Maternal Negative Feelings, Beliefs about Exclusive Maternal Care, Need of Proximity, and Perceptions of Separation Benefits for Children. Confirmatory factor analyses conducted in subsample 2 revealed that the original three-factor structure revealed a poor fit, whereas the four-factor solution revealed an acceptable fit. As in previous studies, our findings report deviations from the original three-factor structure of the MSAS. Three of the newly identified factors seem to reflect specific sub-dimensions that originally guided item development in the MSAS, namely, maternal negative feelings, maternal attitudes about the value of exclusive maternal care, and the need of proximity with the child. The last factor appears to represent a refinement of original items pertaining to perceptions about separation effects for children.

Recent studies of school-age children and adolescents have used social network analyses to characterize selection and socialization aspects of peer groups. Fewer network studies have been reported for preschool classrooms and many of those have focused on structural descriptions of peer networks, and/or, on selection processes rather than on social functions of subgroup membership. In this study we started by identifying and describing different types of affiliative subgroups (HMP- high mutual proximity, LMP- low mutual proximity, and ungrouped children) in a sample of 240 Portuguese preschool children using nearest neighbor observations. Next, we used additional behavioral observations and sociometric data to show that HMP and LMP subgroups are functionally distinct: HMP subgroups appear to reflect friendship relations, whereas LMP subgroups appear to reflect common social goals, but without strong, within-subgroup dyadic ties. Finally, we examined the longitudinal implications of subgroup membership and show that children classified as HMP in consecutive years had more reciprocated friendships than did children whose subgroup classification changed from LMP or ungrouped to HMP. These results extend previous findings reported for North American peer groups.

Describing and explaining the benefits and costs of sociality have occupied the attention of political, social, and economic philosophers and social, behavioral, and developmental scientists for over 400 years. The fundamental questions have been why and how it is that self-interest becomes subordinated (or not) to the interests of group comembers and why or how group norms, values, and structures change as a consequence of the actions of their constituent members and/or the embedding contexts of the group. Whereas philosophical treatments emphasized broad questions about "human nature" (e.g., egoist vs. communal) and the functional attributes of the groups (e.g., task-oriented or norm-enforcing), scientific approaches have tended to be pragmatic and problem focused (e.g., What sorts of structural features characterize different kinds of groups? Do groups have a "developmental" history? To what extent do group structures create affordances and/or impose constraints on the actions and developmental trajectories of members?). Wherever the emphasis was placed and whichever questions were asked, not until the last 80+ years have transactions within children's groups been considered relevant to those questions. In the first half of the 20th century, something of an intellectual sea change appears to have occurred in the behavioral sciences, and several researchers initiated studies of children's groups. This chapter reviews studies of affiliative structures and dominance structures in preschool children's groups.

Parental and peer socialization experiences provide crucial, formative inputs during infancy and early childhood, and by 6 years of age, the child’s brain develops into its full size; the brain’s basic connectivity architecture is laid out, both within and between 'regional' brain areas. Peer affiliation and play, in particular, are extremely important for learning reciprocity and other social and social-cognitive skills; unfortunately, there is a major disparity in the relative inattention to affiliation and play in infancy and early childhood by both society and science. Rather than simply focusing on the individual or peer group as the analytic unit, a complete understanding of human development implies consideration of its multiple contexts, starting with evolutionary history, passing through social dynamics and relationships, to arrive at social ecologies and cultural settings. More than ever, the interdisciplinary field of behavioral biology has great relevance for students of developmental science. Only through concerted effort can we hope to begin the gradual construction of a conceptual and empirical basis for exploring how 'qualitative differences in affiliative relationships and social roles in the stable peer group should be explored in relation to more traditional developmental assessments of individual status and competence'. Future ethological studies must necessarily expand their sociostructural consideration of group processes to include the network of affiliative relations within stable peer groups. Only such a balanced and open-minded approach to cohesive and dispersive activity will permit furthering our understanding of how the peer group may have an impact on children’s social adaptation.

The problem of interpersonal aggression and trait aggressiveness has festered within the social and behavioral sciences as well as in psychiatry for more than a century. Whether the source of the problem is located in the person, as external to the person, or in the contexts that relate the person to environments, most clinical and/or developmental explanations of aggressive behavior and trait aggression have in common the underlying beliefs that aggressive behavior and trait aggressiveness are undesirable, bad, maladaptive, and probably evil. Those beliefs are challenged in this chapter and an account of aggressive behavior and trait aggressiveness that considers the ecological and evolutionary contexts of aggressive behavior and trait aggressiveness is offered as an alternative explanation for these phenomena. On this account, both aggressive behavior and trait aggressiveness are characterized as adaptive solutions to a range of challenges faced by human (and primate) ancestors. As such, aggressive behavior and trait aggressiveness can be considered as normal and expectable in many interpersonal contexts across the human lifespan. Successful aggression will likely be associated with a wide range of positive outcomes and will also likely be observed among the most competent and successful of individuals. However, unsuccessful aggression is likely associated with a range of negative outcomes and will frequently be observed as characteristic of less competent individuals. A selected review of human and nonhuman primate literatures supports these speculative hypotheses, although the authors acknowledge that arguments supporting the adaptive significance of aggressive behavior and trait aggressiveness do not reduce the potential for disruptive consequences in family, classroom, or community life contingent on the expression of trait aggression in these contexts. Some principles concerning the management of children's aggressive behavior deriving from ecological, evolutionary, and social developmental psychology are presented and discussed.