This article is more than 5 years old. Information may no longer be current.
Genetic mental ability suppressed by socioeconomic disadvantage
Tucker-Drob EM. Psychol Sci. 2011;22:125-133.
Click Here to Manage Email Alerts
Children who are raised in socioeconomically disadvantaged environments experience suppression of their genetic mental abilities by age 2 years, researchers found.
Using the Bayley Short Form – Research Edition (BSF-R) for infant mental ability, researchers studied the mental abilities of 750 pairs of twins from across a range of socioeconomic strata. Participants were evaluated at age 10 months and 2 years of age.
At 10 months of age, the mean score was 71.14 (standard deviation=9.09; range, 33.84-112.58), with a reliability of 0.81. At 2 years of age, the mean score was 122.57 (SD=10.80; range, 92.61-159.04), and the reliability was 0.88. The correlation between monozygotic twins was 0.80 at 10 months of age and 0.76 at 2 years of age. The correlation between dizygotic twins was 0.77 at 10 months of age and 0.68 at 2 years of age. All correlations were P<.001.
Socioeconomic status was measured by surveying parents during the first data-collection wave and included the level of parents’ education, their occupations and their total family income. Each variable was standardized to a mean of 0 and an SD of 1. The correlation between socioeconomic status and BSF-R scores was 0.05 at 10 months of age and 0.32 (P<.001) at age 2 years.
The key findings of the study, according to researchers, were that socioeconomic status was unrelated to mental ability at 10 months of age, but was related to mental ability changes between 10 months and 2 years of age; that at the population level, genes’ influence on mental abilities are in the ascendant between 10 months and 2 years of age; and that genetic influence on mental development is attenuated by disadvantaged socioeconomic status.
“These findings are consistent with the hypothesis that the emergence of genetic variation in complex behavioral phenol-types depends on reciprocal interactions between the child and his or her environment. … According to this perspective, poor socioeconomic contexts constrain children’s opportunities to engage with supportive environments that foster cognitive growth, and this constraint results in the suppression of genetic influences on mental ability,” researchers wrote.
 |
Follow the PediatricSuperSite.com on Twitter. |