Social and cultural factors
Another class of explanation also holds that the differences are real, but asserts that they are created by the environmental context. These explanations focus on the effect of educational opportunity, socio-economic status, culture, nutrition and child-rearing practices, among others (Nisbett et al., 2012), on individual differences. These explanations are psychological in nature and focus on the interaction between the individual and the environment. As is true of the genetic explanations, the interactions between the genotypes and environment are too complex to pinpoint the exact impact of the environment on individual differences.
One example of this approach is Cottrell and colleagues’ (2015) model of the factors impacting score differences between African-Americans and Whites on cognitive ability tests.
Their model focuses on a sequential process over time and includes variables related to maternal education, household income, availability of learning materials in the home, parental style, birth order and the physical environment (e.g., overcrowding in the home, safety). In the first step, their model posits that race predicts a number of concepts under the umbrella of ‘maternal advantage’. These include the socio-economic variables of income and maternal education level, as well as maternal verbal ability/ knowledge, due to historical factors such as housing, educational and occupational segregation. In turn, these maternal advantage variables predict a host of parenting factors, including maternal sensitivity to children, acceptance behaviours, the child’s physical environment (e.g., access to healthcare, living in a safe neighbourhood), access to learning materials and birth order and weight (i.e., greater maternal education leads to smaller family size and heavier birth weight, which contribute to a child’s cognitive ability). Finally, these parenting styles proximally predict cognitive ability test scores in the last step. These authors also posit distal relationships between race and parenting factors, and maternal advantage factors and cognitive ability scores. In a longitudinal study of children (five measurement points from age 54 months to 15 years), Cottrell and colleagues found support for their model as a whole and that the score differences between African-Americans and Whites is established by 54 months of age.