Data from Australian adolescents were collected in twin family studies conducted at the Queensland Institute of Medical Research. Participants were mainly recruited through primary and secondary schools in Queensland for studies of melanocytic naevi (moles).45 NEO personality data (NEO-PI-R or NEO-FFI) were collected as part of the cognition study (in-person testing, 1996-ongoing)46, as well as a health and wellbeing study (a mail/phone study 2002-2003)46, and a study of borderline personality disorder (online/paper survey 2004-2006).47 For the current study, personality and genotypic data were available for 1 090 individuals (616 females), of whom 254 were monozygotic twin pairs (for whom average phenotypic data were analyzed). Participants ranged in age from 16 to 27 (M=19.4; SD=3). The mean ages in men and women were very similar (M=19.2, SD=3 in men versus M=19.4, SD=3 in women).
