Correlations with culture are always difficult to interpret because of the numerous, often unmeasured, differences between groups, but the finding that Asian children sometimes display better EF than age-matched Western children is consistent with reports that Chinese parents expect their children to master impulse control at a relatively young age (e.g., Ho, 1994; Wu, 1996; Chen et al., 1998), and that impulse control in daycare settings is more highly valued in China than it is in North America (Tobin et al., 1989). It is also consistent with the finding that the 7-repeat allele of the dopamine D4 receptor gene (DRD4), which has been linked to behavior problems involving EF (e.g., Swanson et al., 1998; Faraone et al., 2001), is extremely rare in individuals from East and South Asia (Chang et al., 1996).