Occupational mobility and cognitive ability: A commentary on Betthäuser, Bourne and Bukodi

This commentary critiques Betthäuser, Bourne and Bukodi's (2020) paper which finds that cognitive ability does not substantially mediate class of origin effects on educational and occupational outcomes. From these results, they conclude that cognitive ability is only of minor importance for social stratification, reasserting their view of the primacy of class origins for social stratification. The central issue surrounding cognitive ability in social stratification is its effects on socioeconomic attainments vis-à-vis socioeconomic origins, not the extent that cognitive ability mediates classorigin effects. Their analytical strategy of estimating the extent that cognitive ability mediates class origineffects is misleading because: it ignores the only moderate associations of socioeconomic origins with educational and occupational outcomes; the stronger direct effects of cognitive ability; the associations of parents' ability with their own socioeconomic attainments; and the genetic transmission of cognitive ability and other traits relevant to social stratification from parents to their children.