deviated from Hardy-Weinberg equilibrium (p = .062, ns). For tests of the G×E hypotheses, DRD4 status was dummy coded; participants carrying at least one l allele were assigned a code of 1 (48.28% of the sample), and participants carrying two s alleles were assigned a code of 0 (51.72% of the sample). Of the participants in the total sample who carried an l allele, 8.52% carried two copies of 7-repeat alleles, 89.1% carried one allele with 7 or more repeats and one with 6 or fewer repeats, and 2.37% carried two alleles with 8 or more repeats. Of the participants in the total sample who carried an s allele, 74.78% carried two copies of the 4-repeat allele. As is conventional in the literature (van IJzendoorn et al., 2011), carriers of one or two copies of an l allele were combined because the number of participants carrying two copies was too small to analyze.
