Genes, interactions, and the development of behavior.

Abstract

Explaining how genes influence behavior is important to many branches of psychology, including development, behavior genetics, and evolutionary psychology. Presented here is a developmental model linking the immediate consequence of gene activity (transcription of messenger RNA molecules from DNA sequences) to behavior through multiple molecular, cellular, and physiological levels. The model provides a level of detail appropriate to theories of behavioral development that recognizes the molecular level of gene action, dispensing with the metaphorical use of such terms as blueprints, plans, or constraints that has obscured much previous discussion. Special attention is paid to the possible role of immediate-early genes in initiating developmental responses to experience, adding specificity to the claim that neither genes nor experience act alone to shape development.The question of how genes affect behavior has been a longstanding focus of both controversy and research within the behavioral and social sciences. It is most directly of concern to the study of behavioral development (Gottlieb, 1998;Wahlsten, 1999) but is also important for behavior genetics (McClearn, Plomin, GoraMaslak, & Crabbe, 1991;Plomin & Rutter, 1998;Turkheimer, 1998) and evolutionary psychology (Buss, 1994;Lloyd, 1999). Although no one today seriously doubts that behavior is influenced in some way by genetic constitution, a general understanding of the mechanisms by which genes exert their influence is still far away. The immediate effect of genes is to specify, through the intermediate stage of messenger RNA (mRNA) synthesis, the polypeptide sequences of various proteins, including those involved in brain structure and function and thus presumably in the organization of behavior. It is, however, a very long step from polypeptide sequences to behavior-a step, moreover, that covers much incompletely understood territory. The aim of this article is to provide a map of that territory, in the form of a model that incorporates genetic influences into a conceptually rigorous account of the development of behavior.This article focuses on the development of behavior. However, genetic activity is involved not only in the developmental transitions between conception and maturity but also in the processes of learning and behavioral plasticity that occur throughout the life span (Robertson, 1992;Tischmeyer & Grimm, 1999). Any account of genetic influences on behavior must include an analysis of the different "causal pathway[s] through which the gene influences the phenotype" (McClearn, et al., 1991, p. 223). Although the techniques of behavioral genetic analysis permit the identification of individual genes with significant effects on behavior (Wahlsten, 1999), understanding how genes influence behavior requires an analysis of the various processes underlying behavioral changes (Gottlieb, 1995).Our analysis extends ideas proposed in earlier articles (Johnston, 1987(Johnston, , 1988 and builds on work done by other developmental theorists working within ...

Genetics and the Social Science Explanation of Individual Outcomes

“…Gene-environment interactions have inspired much recent enthusiasm among social scientists (F. Collins 2004;Johnston and Edwards 2002). Gene-environment interactions imply that the same environmental cause has different effects for individuals who differ in key elements of G. As just discussed, the possible pervasiveness of gene-environment interactions suggests that genetic differences may commonly intrude into explanations specifically in trying to understand why some individuals seem to be more influenced by particular environmental causes than others.…”

Do Schools Moderate the Genetic Determinants of Smoking?

“…Perrin and Lee (2007) argue that gene-environment interaction studies need to understand that "interconnections between individuals and social structures can predict important variations in individual behavior without recourse to individual traits" and thus "environments and genetic potentials must be understood as nested and cross-cutting in potentially complex ways" (311). Nevertheless, the bulk of gene-environment studies continue to focus on the social and demographic characteristics of individuals or families rather than on the composition of larger social contexts such as neighborhoods or schools ) and yet studies at this higher level of aggregation speak more directly to theories of geneenvironment interactions (Johnston and Edwards 2002;Shanahan and Hofer 2005;Perrin and Lee 2007). This perspective is particularly relevant when one considers the social pressures responsible for school and neighborhood segregation by race (Massey and Denton 1993).…”

Three Myths from the Language Acquisition Literature

“…In addition to the numerous studies that have employed experimenter-delivered reinforcement, research has also demonstrated that automatic reinforcement (Vaughan & Michael, 1982) can strengthen vocal behavior in children (e.g., Carroll & Klatt, 2008;Miguel, Carr, & Michael, 2001/2002Smith, Michael, & Sundberg, 1996;Sundberg, Michael, Partington, & Sundberg, 1996;Yoon, 1998;Yoon & Bennett, 2000). Unlike direct reinforcement, which requires the deliberate delivery of reinforcement by another person, automatic reinforcement occurs without the direct mediation of another (Vaughan & Michael).…”

“…More recently, the partitioning of nature and nurture has been eschewed and, in its place, interactionism has become the doctrine professed by many developmentalists (e.g., Anastasi, 1958;Johnston, 1987Johnston, , 1988Johnston, , 2002Moore, 2001) within the life sciences. According to Anastasi, efforts to determine the relative contributions of nature and nurture have not been successful.…”