Polygenic scores for smoking and educational attainment have independent influences on academic success and adjustment in adolescence and educational attainment in adulthood.

Brian M Hicks,Jonathan D Schaefer,Seonkyeong Jang,Mengzhen Liu,Scott I Vrieze,Wendy Johnson,D Angus Clark,C Emily Durbin,Matt Mcgue,Joseph D Deak,William G Iacono,Sylia Wilson,Edelyn Verona

doi:10.1371/journal.pone.0255348

Abstract

Educational success is associated with greater quality of life and depends, in part, on heritable cognitive and non-cognitive traits. We used polygenic scores (PGS) for smoking and educational attainment to examine different genetic influences on facets of academic adjustment in adolescence and educational attainment in adulthood. PGSs were calculated for participants of the Minnesota Twin Family Study (N = 3225) and included as predictors of grades, academic motivation, and discipline problems at ages 11, 14, and 17 years-old, cigarettes per day from ages 14 to 24 years old, and educational attainment in adulthood (mean age 29.4 years). Smoking and educational attainment PGSs had significant incremental associations with each academic variable and cigarettes per day. About half of the adjusted effects of the smoking and education PGSs on educational attainment in adulthood were mediated by the academic variables in adolescence. Cigarettes per day from ages 14 to 24 years old did not account for the effect of the smoking PGS on educational attainment, suggesting the smoking PGS indexes genetic influences related to general behavioral disinhibition. In sum, distinct genetic influences measured by the smoking and educational attainment PGSs contribute to academic adjustment in adolescence and educational attainment in adulthood.

Highlights

Educational success is important for a variety of important life outcomes including wealth accumulation, health and longevity, and happiness [1,2,3]
Our analyses demonstrated that genetic influences on smoking provide incremental prediction of educational attainment, even after accounting for a polygenic scores (PGS) designed to predict educational attainment
This indicates that PGSs calibrated on different phenotypes can provide additional information about genetic influences on a target phenotype, even ones that have already been the subject of large gene discovery analyses

Summary

Introduction

Educational success is important for a variety of important life outcomes including wealth accumulation, health and longevity, and happiness [1,2,3]. Externalizing problems are manifestations of these poor inhibitory abilities and include impulsivity, aggression, rule breaking, oppositionality, hyperactivity, and inattention They are associated with lower grades, poor academic motivation, and more disciplinary problems, and predict lower educational attainment [20, 21], with most of the overlap attributable to shared genetic influences [9]. We took a developmental approach and examined associations between the PGSs for smoking and educational attainment and several intermediate phenotypes that contribute to educational success including grades, academic motivation, and disciplinary problems in childhood and adolescence We operationalized these intermediate academic phenotypes using the stable variance across multiple occasions (ages 11, 14, and 17-years old), which removed time-specific influences and unsystematic measurement error from these measures. We examined whether the expressed phenotype of cigarettes per day from ages 14 to 24 years old accounted for the association between the smoking PGS and educational attainment, or if the effect of the smoking PGS was mediated through the academic variables, which would be more consistent with a general effect of behavioral disinhibition

Participants

Results

Discussion