Gene-Environment Correlations in Children's Problems with Peers

On April 10, Professor Ariel Knafo (Hebref University of Jerusalem) took part in the «Culture matters» seminar.

A. Knafo has presented his work on the genetic and environmental influences on interpersonal relationships. The effects of the genes on interpersonal relations has been shown in earlier research (Boldvin; Beinsh-Welsman; Steinberg-Knafo). In his study, Knafo has tested a hypothesis that the relationship between the genes and the quality of interpersonal relationships is mediated by temperament. 268 pairs of monozygotic twins and 526 pairs of dizygotic twins have participated in the study. The design was longitudinal, the testing included the measures of interpersonal problems and temperament and was conducted when the twins were 3, 5, and 6 years of age. Data analysis has shown that interpersonal problems become less pronounced over time, and that both genetic and environmental factors play a role (the scores on interpersonal problems questionnaires correlated stronger among monozygotic than among dizygotic twins). The effects of shared environment faded over time: they were the strongest among the 3 year olds and almost completely disappeared by 6 years of age. The levels of interpersonal problems strongly correlated with the participants’ temperament: positively with negative emotionality and shyness, and negatively with sociability and activity. The temperament scores obtained from 3 year olds predicted their level of interpersonal problems at age 6. A structural model was developed based on the data from the study. The model explains the differences in interpersonal problems through genetic factors that affect children’s behavior which, in its turn, affects peers reactions. The study provided support to the hypothesis on the mediating role of temperament in the relationship between genetic factors and quality of interpersonal relationships.