Читать книгу The Wiley-Blackwell Handbook of Childhood Social Development - Группа авторов - Страница 23

The discipline of behavioral genetics emerged during the 1960s and one of its aims was to estimate the heritability of human characteristics or behaviors. Because the human genotype could not be studied directly, genetic influence was investigated indirectly using adoption and twin studies and findings substantiated the heritability of many social characteristics (e.g., temperament, personality, aggression; Rutter, 2006).

As subsequently detailed, theoretical and investigative innovations enabled researchers to address more challenging questions (e.g., How do genetic and environmental influences combine to influence behavior? Scarr & McCartney, 1983; Rutter, 2006), but also generated controversies about the relative importance of genetic versus environmental influences. One such debate revolved around the contention that parental genes made a stronger contribution to children’s development than parenting behavior (Harris, 1995; Vandell, 2000).

As direct approaches to studying genes emerged, disciplines such as genomics and molecular genetics were formed. Innovations such as DNA sequencing techniques and the mapping of the human genome (Collins et al., 2003) made it possible to examine the association between specific genes and phenotypical social attributes.

The likelihood that multiple rather than single genes underlie observable characteristics, and the near‐infinite number of combinations thereof, complicated research on the genetic bases of social characteristics. Nonetheless, evidence began to reveal how specific genes, in combination with particular rearing conditions, were linked with children’s social development. In one such study (Caspi et al., 2002), it was discovered that the effects of parental maltreatment were moderated by children’s genetic susceptibility to that particular stressor. Children with low‐activity MAOA (monoamine oxidase A: a gene that breaks down stress‐linked neurotransmitters) tended to develop higher levels of antisocial behavior than those with high‐activity MAOA. Other findings showed that children who possessed a gene configuration linked to self‐regulation difficulties (i.e., chromosome 7 gene with short 5‐HTTPR) and experienced low‐quality parenting were more likely to develop externalizing problems (Davies & Cicchetti, 2014).