Expanding the environment: gene × school‐level SES interaction on reading comprehension

Abstract

Background Influential work has explored the role of family socioeconomic status (SES) as an environmental moderator of genetic and environmental influences on cognitive outcomes. This work has provided evidence that socioeconomic circumstances differentially impact the heritability of cognitive abilities, generally supporting the bioecological model in that genetic influences are greater at higher levels of family SES. The present work expanded consideration of the environment, using school-level SES as a moderator of reading comprehension. Methods The sample included 577 pairs of twins from the Florida Twin Project on Reading, Behavior and Environment. Reading comprehension was measured by the Florida Comprehensive Achievement Test (FCAT) Reading in third or fourth grade. School-level SES was measured by the mean Free and Reduced Lunch Status (FRLS) of the schoolmates of the twins. Results The best-fitting univariate G × E moderation model indicated greater genetic influences on reading comprehension when fewer schoolmates qualified for FRLS (i.e., “higher” school-level SES). There was also an indication of moderation of the shared environment; there were greater shared environmental influences on reading comprehension at higher school-level SES. Conclusions The results supported the bioecological model; greater genetic variance was found in school environments in which student populations experienced less poverty. In general, “higher” school-level SES allowed genetic and probably shared environmental variance to contribute as sources of individual differences in reading comprehension outcomes. Poverty suppresses these influences.

When does socioeconomic status (SES) moderate the heritability of IQ? No evidence for g × SES interaction for IQ in a representative sample of 1176 Australian adolescent twin pairs

“…It has been suggested that failures to find gene × SES effects are due to either sample selection -for instance twin pairs pre-selected for passing IQ criteria for admission to the US Armed Forces (Grant et al, 2010) or low sample size. This cannot explain, however, unpublished data in a representative sample of Florida children which failed to find gene × SES interaction (Soden-Hensler, 2012), although a significant gene interaction with a measure of school quality based on number of deprived students in the school was reported (Hart, Soden, Johnson, Schatschneider, & Taylor, 2013).…”

“…These data indicate that parental SES is not an obligate moderator of genetic variance in IQ. Along with other results (Hanscombe et al, 2012;Hart et al, 2013), the findings thus constrain and inform bioecological models which suggest a monotonic increase in heritability across varied environmental resources (Bronfenbrenner & Ceci, 1994).…”

“…The finding that attending preschool reduces SES-linked achievement differentials suggests that school provides the substantive environment underlying differences in the expression of genetic potential in achieved intellectual capacity (Tucker-Drob, 2012). It is possible that, in comparison to the US, aspects of the funding or management of Australian education act to provide educational environments more similar to those that, in the US also, act to reduce SES interactions on heritability (Hart et al, 2013). The nature of these factors is currently, however, unclear.…”

Genetic and Environmental Influences on Literacy and Numeracy Performance in Australian School Children in Grades 3, 5, 7, and 9

“…Finally, there are numerous studies that find no significant sex-effects in various measures of reading and math (e.g. Davis et al Behav Genet 2008;Hart et al 2013;Wadsworth and DeFries 2005).…”

Familial Risk Across Three Generations and Psychosocial Correlates for Developing Psychopathology in a Changing World

“…There are several types of rGE that play a substantial role in influencing environmental risk exposure, but their impact is best understood through the effects of parent and child behaviors in shaping and selecting environments [14]. Studies exploring the role of family social economic status (SES) as a moderator of genetic and environmental influences on general cognitive ability have provided evidence that socioeconomic circumstances differentially impact the heritability of cognitive abilities [15]. Furthermore, as SES is correlated with differences in life stress and family resources (e.g.…”