U of the restriction enzyme BsrI (New England Biolabs, Cat#R0527L). The products were electrophoresed through 10% Polyacrylamide gel(Acrylamide/bis-Acrylamide ratio 19:1) at 150 V for 40 min. 10bp marker was used to measure the fragments size. The A allele yields 164bp, 136bp and 8bp. The G allele yields 164bp, 101bp, 34 and 8bp. All genotypes were scored by research assistants who had no knowledge of the phenotypic data. This genotyping yielded three groups of girls: 86 girls carrying two G alleles (GG), 41 girls carrying one A and one G allele (AG), and 2 girls carrying two A alleles (AA). Because OXTR rs2254298 SNP exhibits a different allele frequency in Asian and Caucasian populations (www.hapmap.org), and the sizes of the minority samples in this study do not allow for reliable comparison, we report findings only for the Caucasian girls (n=92), who comprised 72.1% of the overall sample of GGs (n=62), 70.7% of AGs (n=29), and 50% of AAs (n=1). The allelic frequencies for OXTR SNP rs2254298 were in the Hardy-Weinberg equilibrium, χ2= 1.44 (df=2, n=92), ns. The single AA Caucasian girl was excluded from the remaining analyses. Thus, we present results below for the Caucasian girls: 38 low-adversity GGs, 22 low-adversity
