Numerous studies have linked poverty to low IQ scores and poor school performance. New studies offer insights into why.

“Early life experiences influence a child’s brain development,” Martha Farah told scientists who gathered at the “Poverty and the Brain” symposium at the 2008 annual meeting of the American Association for the Advancement of Science (AAAS) Feb. 15. Farah, director of the Center for Cognitive Neuroscience at the University of Pennsylvania, reported on new studies of 110 children born to mothers receiving public assistance.

In past work, Farah and her colleagues found links between socioeconomic status (SES) and differences in children’s language, memory, and “executive functions” such as working memory and self-control. In the new research, children’s home lives were studied extensively at ages 4 and 8. At middle-school age, the children’s cognitive abilities were tested.

Farah found a positive correlation between toys and activities in the home and a child’s language development: The more stimulating the environment, the better the child’s language skills.

More surprising, she found that parental nurturing affected memory. The more loving, attentive, and accessible the parent(s), the better the child’s memory.

“We know that the lower a family’s SES level, the higher the level of stress on everyone, children included,” Farah says. “So poor children are especially vulnerable to the effects of stress on brain development. Good parental nurturance buffers against this risk.”