Power analyses showed that the genome-wide significant variants could not have been detected in any of the individual studies at the genome-wide significant level (power to detect these effects at α=5 × 10−8 in sample sizes smaller than 4 000 is less than 1%), but the power to detect these effects in the current meta-analytic study with a sample size of 17 375 is 77% for the top SNP for Openness to Experience and 72% for the top SNP of Conscientiousness. Additional power analyses showed that with a power of 80%, the meta-analysis could detect much smaller effect sizes than any of the individual studies (0.23% explained variance versus 1% to 6.5% explained variance for sample size of individual studies between 600 and 3 972; explained variances correspond to standardized betas of 0.05 versus 0.1 to 0.25).
