outcomes) was due to correlation among the phenotypes (Dick, Aliev, et al., 2007; Luo et al., 2005). However, these remarkably consistent early findings have more recently been joined by failures to replicate, with a new study finding no evidence of association between CHRM2 and cognitive ability across three independent samples (Lind et al., 2009). Further, we did not find strong evidence for main effects of CHRM2 on externalizing behavior in the CDP.
