Neural Reuse as a Source of Developmental Homology

Neural reuse theories should interest developmental psychologists because these theories can potentially illuminate the developmental relations among psychological characteristics observed across the lifespan. Characteristics that develop by exploiting pre-existing neural circuits can be thought of as developmental homologues. And, understood in this way, the homology concept that has proven valuable for evolutionary biologists can be used productively to study psychological/behavioral development

Trying to Fix the Development in Evolutionary Developmental Psychology

If we agree for a moment that there is such a thing as human nature, we immediately encounter an extraordinarily thorny question: Where does our nature come from? This question drives David Bjorklund and Anthony Pellegrini’s new book The Origins of Human Nature: Evolutionary Developmental Psychology. The question is so challenging, in part, because human nature reflects at least two conceptually distinct processes: evolution and development. The former, which operates across generations, allows the continued existence of characteristics that permitted survival and reproduction in our ancestors; the latter, which operates during a person’s lifetime, contributes to the appearance of all of our characteristics. The problem of facing students to human nature is how to understand the relationship between these processes and how they contribute to the appearance of our traits

Integrating Development and Evolution in Psychology: Looking Back, Moving Forward

This work is the editorial for a special edition of New Ideas in Psychology titled Integrating Development and Evolution in Psychology

Individuals and Populations: How Biology\u27s Theory and Data have Interfered with the Integration of Development and Evolution

Research programs in quantitative behavior genetics and evolutionary psychology have contributed to the widespread belief that some psychological characteristics can be “inherited” via genetic mechanisms. In fact, molecular and developmental biologists have concluded that while genetic factors contribute to the development of all of our traits, non-genetic factors always do too, and in ways that make them no less important than genetic factors. This insight demands a reworking of the Modern Evolutionary Synthesis, a theory that defined evolution as a process involving changes in the frequencies of genes in populations, and that envisioned no role for experiential factors now known to play essential roles in adaptive trait development. Furthermore, since evolution has been taken to be strictly a population-level phenomenon while development affects individuals, the two have been understood to require different levels of analysis; this understanding has given rise to incompatible research programs. This state of affairs is untenable because development and evolution mutually influence one another in fundamental ways, several of which are detailed in this article. The balance of this paper considers the conceptual problem that has arisen because understandings generated by developmental scientists cannot be enhanced by studies designed merely to account for variation across populations. Because the theoretical conceptions and methodological tools used to study development and evolution have produced non-corresponding sets of information about these closely related and mutually influential biological processes, these conceptions and tools are interfering with the establishment of a unified theory of biology that encompasses both phenomena

A Very Little Bit of Knowledge: Re-Evaluating the Meaning of the Heritability of IQ

There is a deeper assumption underlying adoption studies that is often not acknowledged by either adoption study researchers or their critics, and it is an assumptions that is at least as important as the two considered by Richardson and Norgate: the assumption that the heritability statistics generated by adoption studies are informative about something of consequence. Although Richardson and Norgate’s paper presents several valid criticisms of adoption studies of IQ that lead them to suggest a ‘radical reappraisal’ of such studies, a reappraisal even more radical than the one they suggest might, in fact, be warranted

Espousing Interactions and Fielding Reactions: Addressing Laypeople\u27s Beliefs About Genetic Determinism

Although biologists and philosophers of science generally agree that genes cannot determine the forms of biological and psychological traits, students, journalists, politicians, and other members of the general public nonetheless continue to embrace genetic determinism. This article identifies some of the concerns typically raised by individuals when they first encounter the systems perspective that biologists and philosophers of science now favor over genetic determinism, and uses arguments informed by that perspective to address those concerns. No definitive statements can yet be made about why genetic determinism has proven so resilient in the face of empirical evidence pointing up its deficiencies, but conveying the essential interdependence of ‘nature’ and ‘nurture’ to the general public will likely require deployment of the arguments that systems theorists ordinarily use to reject genetic determinism. In addition, the elaboration of new metaphors that focus attention on the dynamic nature of trait construction will likely prove valuable, because re-conceptualizing notions like ‘genes’ and ‘nature’ will probably be one of the most effective ways to help students and the general public abandon the genetic determinism that biologists now recognize as indefensible

Probing Predispositions: The Pragmatism of a Process Perspective

As J. P. Spencer et al. (2009) argue, the theories of some developmental psychologists continue to be nativistic, even though nativism is an inherently nondevelopmental school of thought. Psychologists interested in development study the emergence of human characteristics—including predispositions—and are not content to simply catalogue competences that characterize human newborns; instead, they recognize that all human characteristics, including those present at birth, reflect the circumstances of development. A truly developmental science of behavior requires rejecting the nativism–empiricism debate outright, abandoning ideas such as “core knowledge” and psychological “endowments,” and adopting a process perspective that focuses on how traits emerge from the co-actions of biological and experiential factors. Unlike nativism, the process perspective advocated by J. P. Spencer et al. encourages research that can reveal the developmental origins of psychological characteristics of interest

Sex Differences in Normal Fetuses and Infants: A Commentary

Sex differences in infants warrant attention, not because they clarify the extent to which such differences reflect nature or nurture, but because studying them is likely to illuminate the origins of sex differences later in life and thereby yield manipulations that could influence the development of important competences. It is not yet clear how male and female infants come to differ. Testosterone is influential, but because of the complexity of the developmental systems in which it operates, its effects are not straightforward: Testosterone does different things in different contexts. Simple explanations invoking hormone exposure should not be expected to satisfactorily answer questions about the origins of sex differences, but standardizing protocols to allow meaningful meta-analyses would help bring coherence to the research literature in this domain