Means and standard deviations, and the results of regression analyses examining the effects of age and sex on each of the study variables, are presented in Table 1. Maternal and paternal negativity were both negatively related to age indicating that in our sample younger adolescents reported experiencing more negativity than did older adolescents. The experience of negative life events was unrelated to age. None of the environmental phenotypes differed between girls and boys. For the behavioural phenotypes delinquency was positively related to age, whereas anxiety, oppositionality and physical aggression were negatively related to age. Depression was unrelated to age. Girls reported experiencing more depression and anxiety symptoms than boys. Boys reported higher levels of delinquency, and physical aggression than girls. Oppositionality did not differ between the sexes.Table 1Descriptive statistics and tests for sex and age effects on all variables included in the studyBoysGirlsSexAgeMSDMSDβ (95 % CI)β (95 % CI)Maternal negativity7.293.847.723.900.06 (−0.01, 0.13)−0.10 (−0.17, −0.04)*Paternal negativity7.014.507.024.430.01 (−0.06, 0.07)−0.12 (−0.19, −0.05)*Negative life events1.151.371.221.410.02 (−0.04, 0.09)0.03 (−0.04, 0.09)Depression6.705.558.587.290.14 (0.07, 0.21)*0.03 (−0.04, 0.10)Total anxiety20.7812.6925.9714.210.19 (0.13, 0.25)*−0.07 (−0.14, −0.01)*Oppositionality3.942.964.052.980.02 (−0.04, 0.09)−0.08 (−0.15, −0.01)*Delinquency3.292.902.652.43−0.25 (−0.36, −0.13)*0.47
