Recall what you know from Unit 2 on the biological approach to behaviour, and say how the eects of poverty on cognitive development link to the following ideas and research studies.

● Adoption studies of heritability of intelligence

(Kendler et al, 2015; Scarr and Weinberg, 1983):

adopting into a higher-income family increases the IQ of the child, but by the age of 18 the correlation of IQ with that of biological parents is stronger.

● Behavioural epigenetics (Weaver et al, 2004): less nurturing in early childhood is associated with greater methylation of the glucocorticoid receptor gene, which results in fewer glucocorticoid receptors in the brain and higher stress levels later in life.