Nature or nuture? Understanding the underpinnings of childhood resilience

Many children who grow up in poverty have higher levels of behavioral problems and lower IQ scores than children who grow up in middle class families. However, some children from poor family backgrounds are resilient — that is, they behave better and score higher on intelligence tests than might be expected given the level of social and economic deprivation they have experienced.

Researchers have identified several protective factors that promote children’s resilience, including a child’s easy, sociable personality, a mother’s warmth toward her child, and a stimulating home environment. However, we still don’t know to what extent these protective factors and children’s resilience might be associated with a common genetic factor. It may be that the genes involved in promoting the protective factor are the same genes that promote child’s positive development under conditions of poverty. For instance, the genes that contribute to a mother’s emotional warmth could be the same genes she passes onto her child, which promote the child’s resilience. In this study, we tried to determine the degree to which genetic versus social-environmental influences explain children’s resilience against poverty.

We interviewed 1,116 mothers and their 5-year-old twins in the United Kingdom to assess the family’s level of socioeconomic hardship, the twins’ antisocial behavior at home, and their IQ. We also received reports from teachers about the twins’ behavior at school.

We identified children as “behaviorally resilient” if their actual score on antisocial behavior was unexpectedly lower (i.e., better) than the score predicted by their family’s level of socioeconomic deprivation. Additionally, we identified them as “cognitively resilient” if their IQ score was unexpectedly higher (i.e., better) than the score predicted by their family’s level of socioeconomic deprivation. Studying twins allowed us to compare the similarities between identical twin pairs, who share all their genes, and fraternal twin pairs, who share about half their genes. If the similarity in resilience between identical twins is greater than the similarity between fraternal twins, it suggests that genes influence resilience.

And that is just what we found–that children’s behavioral and cognitive resilience to poverty was influenced by their genetic makeup. This suggests that children themselves are agents in rising above their experience of poverty. For example, we found that children with a genetic disposition to be friendly, sociable, and outgoing had the most resilience against poverty.

Importantly, however, children’s resilience was also affected by their rearing environment. After controlling for genetic effects, we found that mothers who engaged in more stimulating activities with their twins helped promote their children’s resilience against poverty. This finding suggests that encouraging parents to engage in activities with their children (e.g., a long walk or a museum visit) can help protect children’s intellectual development from the damaging effects of socioeconomic deprivation.

Thus, both genetic and social-environmental sources of protection are involved in helping children overcome the hardship of growing up poor.