Continuing with my running commentary on Meng Hu’s Re-analysis of Jensen’s study of Capron and Duyme adoption data post, I looked at the correlation between g-loadings and sibling correlations in the Texas Adoption Study. Loehlin et al. (1994) reported father, mother — biological, adopted offspring correlations. I correlated these with the g-loadings reported by Kan (2011), as in the previous analysis. Below: (1) r average adoptive father + mother – adopted offspring, (2) r adoptive father – adopted offspring, (3) r adoptive mother – adopted offspring, (4) r average biological father + mother – reared biological offspring, (5) r biological father – reared biological offspring, (6) r biological mother – reared biological offspring, (7) r biological mother — reared apart biological offspring, (8) average Wechsler g-loadings, (9) average of the g-loadings for the tests used. There was an initial assessment and a 10 year follow up; correlations were averaged across both times. The Jensen Effect on r average adoptive father + mother – adopted offspring was 0.18/0.14. For comparison, the Jensen Effect on r average biological father + mother – reared biological offspring was 0.49/0.47.
These results are basically consistent with what I mused prior: “While shared environment probably doesn’t induce strong positive Jensen Effects and therefore probably can’t explain the Jensen Effects on ethnic group differences, the effects that it seems to induce i.e, a weak to modest positive one…..”
Loehlin, J. C., Horn, J. M., & Willerman, L. (1994). Differential inheritance of mental abilities in the Texas Adoption Project. Intelligence, 19(3), 325-336.