The Genetics of Sexuality and Aggression sample is a population‐based cohort of Finnish twins and siblings of twins. The subsample used in the present study stems from the second data collection completed in 2006 (for data collection procedure, see Johansson et al. 2013). DNA was extracted from saliva samples (for characteristics, see Table 1). Some genotyping failure was seen for each of the analyzed SNPs resulting in a slight variation in n. The genotypes were imputed in cases where only one of the monozygotic twins was genotyped. A number of subjects with at least one successfully genotyped SNP in the resulting sample were 4161 subjects from a total of 1756 families (581 monozygotic and 380 dizygotic twin‐pairs, 910 siblings and 1329 singletons).
