@article {SARRAF2023111969, title = {The anti-Wilson effect: The decrease in heritability of general cognitive ability, as proxied by polygenic expressivity, with advanced age}, journal = {Personality and Individual Differences}, volume = {202}, year = {2023}, pages = {111969}, abstract = {Polygenic expressivity on general cognitive ability (GCA) declines with increasing age in a cohort of 5,236 individuals born from 1916 to 1955 sourced from the Health and Retirement Study. The effect is detected with a two-way interaction between participant birth year and an educational attainment polygenic score (PGS) predicting GCA, and is robust to controlling hierarchically for population stratification and the main effects of the PGS and participant birth year, in addition to interactions involving all of these factors. The effect can also be recovered using the continuous parameter estimation model, an alternative method for detecting moderation/interaction effects. These findings suggest that the true relationship between the heritability of GCA and age is (likely) best captured by a negative quadratic model, with the Wilson effect beginning to give way to the anti-Wilson effect in the 50{\textendash}69 years age range. This anti-Wilson effect is likely a function of broad age-related cognitive decline (which is also found in the current study), reflecting reduced phenotypic system integrity associated with accumulating somatic mutations and phenotypic insults. These likely depress cognitive performance (e.g., accuracy and processing efficiency), causing a reduction in apparent heritability due to increased error.}, keywords = {Age-related cognitive change, Anti-Wilson effect, Wilson effect}, issn = {0191-8869}, doi = {https://doi.org/10.1016/j.paid.2022.111969}, author = {Matthew A. Sarraf and Michael A. Woodley of Menie and Mateo Pe{\~n}aherrera-Aguirre} }