Estradiol, testosterone, differential association and aggressive and non-aggressive risk-taking in adolescent girls.

Although the relation between androgens and adolescent risk-taking has been relatively well documented in boys, little is known as to how sex steroid hormones relate to aggressive (ART) and/or non-aggressive adolescent risk-taking (NART) behavior in girls. On the basis of a sample of 298 adolescent girls (mean age: 14.3 years), we examined: (i) the relationship between serum levels of testosterone (T) and estradiol (E2) in relation to ART and NART and (ii) if differential association--having friends who are highly involved in risk-taking--moderates the relationship between relationships between hormones and risk-taking. The sample provided evidence of an association between free estradiol (FE2) and both NART (Beta=0.19; p<0.01) and ART (Beta=0.19; p<0.01), controlling for age and pubertal development. No relationship between T and ART or NART was found. The importance of the relationship between E2 and ART and NART differed between girls at different phases of their menstrual cycle and was significant only for girls in the mid-phase of the menstrual cycle. In addition, significant interactions between differential association and FE2 were found indicating that the relationship between FE2 and NART and ART was particularly strong in girls with high levels of differential association.