Discuss the role of genetics & cultural differences in the development of intelligence.

‘Culture’ refers to the rules, morals and methods of interaction that bind a group of people and which are determined through the process of socialization. Socialization is achieved largely through parents, school and peers, as well as members of one’s culture in general. These individuals may influence IQ. Cultural factors are also apparent in differences in the desire to succeed. In an investigation into home background, the Rochester Longitudinal Study (Sameroff et al. 1993) that began in the 1970s has followed several hundred children from birth to adolescence. It has identified 10 environmental factors that were found to affect the children’s IQ. The more factors a child had, the lower their IQ. In fact, IQ decreased at a rate of about 4 IQ points per factor, and together the factors were found to account for almost half the variability in children’s IQ scores. However, these data are correlational. It may be that low parental IQ was the cause of the risk factors (e.g. ‘mother did not go to high school’) and also the cause of low IQ in the child (child inherited low IQ). A study by Hart and Risley (1995), focusing on parental involvement, also conducted a long-term investigation of children’s development. They looked in particular at the verbal interactions between parents and children, analyzing tape recordings taken during the children’s first three years. All the children started speaking at about the same time, but by the age of three there were significant differences in vocabulary, which were associated with home background. Children from professional families had about 1,100 words, children from working –class families had 750 words and those from families on welfare had just above 500 words. These differences were related to language use in parents. Hart and Risley identified five parent behaviours that were strongly related to vocabulary developments in children. There were: using a wide vocabulary, high rates of approval, language with a high information content, asking children about things rather than being directive, and responding to children. There was a correlation of 0.78 between IQ at age 3 and these parenting behaviours. Research by Shuey (1966) found that on average, black Americans score 15 points lower than white Americans on IQ tests. Goddard (1929) stated that ¾ of the Italians, Jews and Russians tested were feeble minded. This lead to mass deportation and the introduction of the 1917 immigration act. Jensen (1969) argued that the difference between the two groups was the result of genetic differences. Scarr & Weinberg (1976) showed that for black children adopted into white families, IQ scores were 25 points higher than the mean for black children in general.