Two studies published this year have made life significantly more difficult for those who continue to be optimists. The first one is by Florida State University's Kevin Beaver and five colleagues, who asked how much effect parenting has on IQ independently of genes. The database they used, the National Longitudinal Study of Adolescent Health, is large, nationally representative and highly regarded. The measures of parenting included indicators for parental engagement, attachment, involvement and permissiveness. The researchers controlled for age, sex, race and neighborhood disadvantage. Their analytic model, which compares adoptees with biological children, is powerful, and their statistical methods are sophisticated and rigorous.