Indirect effects of parental education polygenic score on offspring educational attainment via parental educational attainment, income, and parenting were tested using the MODEL INDIRECT command in Mplus, which provides a test of specific indirect effects in addition to the total indirect and direct effects of parental education polygenic score on offspring educational attainment. In cases where multiple indirect pathways are examined simultaneously, specified indirect effects reflect each of the specific pathways (e.g., parental education polygenic score → parental educational attainment → offspring educational attainment) while also accounting for the shared associations between them. Indirect effects were evaluated using bias-corrected bootstrapping (5,000 times) 95% confidence intervals (CI; MacKinnon et al., 2004), with CI not including zero indicating statistically significant indirect effects.
