Genetic and Environmental Influences on the Individual Differences of Temperament in Primary School Children

The current study estimated the contributions of genetic and environmental influences into the variability of temperament specifics in primary school children. We assessed the temperamental traits with the use of Russian-language parent version of M. Rothbart's questionnaire. The sample included 170 children (85 twin pairs) aged 7 to 10: 49 monozygotic twin pairs and 36 same-sex dizygotic twin pairs. Contributions of genetic and environmental influences were estimated by means of structural equation modeling. Factor analysis revealed three common factors: "Attention -control", "Extraversion - Positive Emotions", "Fear - Negative Emotions". The most significant contributions of the genotype were found for the following scales: "Fear", "Inhibitory Control", "Shyness" and "Depressive Mood". Common environment contributions were most significant for the scales "Activation Control", "Aggression", "Frustration" and "High Intensity Pleasure". Two common higher level factors corresponding to control and positive emotions were associated with the influences of "common environment", whereas negative emotions factor is influenced by genes. (C) 2013 The Authors. Published by Elsevier Ltd.