To explore the relation between childhood sexual behaviour and adolescent sexual behaviour, and possible mechanism underlying this relationship (e.g., the roles of childhood gender-typed behaviour, childhood victimisation, childhood and adolescent intimate friendships, and pubertal development).

Middle childhood--conventionally defined as between 6 to 11 years of age--provides rich contexts in which sexual orientation might develop. It nurtures intimate same-sex friendships [1], and coincides with adrenarche--a potential biological catalyst for the emergence of sexual attraction [2]. Sexual behaviour (e.g., masturbation) in middle childhood may be related to adolescent sexual orientation in at least 2 ways: The pleasure resulting from genital stimulation during adrenarche may involve same-sex friends in intimate interactions, which may lead to adolescent same-sex sexual attraction and activities.

Also, childhood gender atypicality may be involved in the link between childhood sexual behaviour and adolesent sexual orientation: for example, gender atypicality in middle childhood may increase victimization, which could be associated with increased childhood sexual behaviour, perhaps to offset negative emotions [3]; in addition, childhood gender atypicality is directly linked to same-sex sexual orientation [4].