Written by: Stephen Hsu
Primary Source: Information Processing
The working paper below on multigenerational mobility arrives at smaller intergenerational correlations than Greg Clark obtained (e.g., 0.4 vs 0.7). I found Clark’s results hard to explain, at least in genetic terms, because estimates of assortativity in mating are much lower than required.
Correlations as high as 0.7 — 0.8 are implausible from genetic factors alone without highly assortative mating. Traits such as height and IQ have narrow sense heritabilities as large as h2 ~ 0.6, so fraction of variance accounted for is ~ 60%, and midparent-child correlation as high as ~ 0.8, but under even somewhat random mating the parental midpoint is significantly closer to average than the phenotype of the more exceptional parent. This would cause children to regress to the mean much faster in height and IQ than in social status as indicated in Clark’s data. It’s also important to note that social status itself is only imperfectly correlated to observable phenotypes such as IQ, Conscientiousness or Extraversion. See Intergenerational mobility: Bowles, Gintis, Clark for more.
Solon’s results seem to be consistent with Bowles and Gintis.
Michigan State University
“Multigenerational mobility” refers to the associations in socioeconomic status across three or more generations. This article begins by summarizing the longstanding but recently growing empirical literature on multigenerational mobility. It then discusses multiple theoretical interpretations of the empirical patterns, including the one recently proposed in Gregory Clark’s book The Son Also Rises.
… contrary to Clark’s prediction, most group-average studies other than his own – including the surnames-based work by Chetty et al. – have estimated much smaller intergenerational associations.
Clark was recently interviewed on KQED Forum. Michael Krasny was willing to entertain Clark’s Social Darwinistic perspective ;-)