We report here the results of the largest GWAS conducted to date for personality assessed using the TCI. The lack of genome-wide significant associations in our meta-analysis of more than 11 000 subjects, and the lack of replicated associations for personality measured by the NEO-PI-R in an even larger meta-analysis15 suggest that it will be challenging to identify such associations using standard approaches for studying personality traits. Although we find modest association of the top findings of de Moor et al.15 to some of our phenotypes, the statistical evidence is well below the level required for replication. Additionally, we find no association evidence to support the suggestion of Cloninger16 that NS, HA and RD would be influenced by genes directly affecting the dopamine, serotoneric or noradrenaline systems, respectively. Two previous studies have identified genome-wide significant linkage to HA36 and NS.37 None of our top association signals (P<10−5) for these phenotypes were on the same chromosomal arms as these linkage findings.
