It was important to gauge whether the above developmental findings more closely reflected baseline or follow-up status. Therefore, an exploratory/post-hoc analysis of the baseline and follow-up data was conducted using the same statistical methods as above. We applied a conservative Bonferroni correction of p < .0031 to correct for 16 additional tests. No significant SNP × digit span interactions were detected in baseline analyses (Supplementary Table 2). By contrast, the two significant interactions between DRD1 SNPs rs4532 and rs265978 and digit span backward that emerged during development were also significant at follow-up after correction for multiple testing (Supplementary Table 3). Lastly, no DRD2 × digit span interactions were significant.
