Growing up poor can be hazardous to a child's physical and emotional well-being; and those hazards can continue over a lifetime, even if an individual escapes poverty in adulthood.
But while studies have linked childhood poverty to a host of long-term negative consequences -- including poorer physical health, achievement deficits, depression, anxiety, impaired working memory, unstable relationships, elevated aggression, delinquency and substance abuse -- it's not clear what underlying mechanisms are responsible for the discrepancies.
With a grant for $1.4 million over two years from the American Recovery and Reinvestment Act (ARRA), environmental psychologist Gary Evans, the Elizabeth Lee Vincent Professor of Human Ecology, and collaborators James Swain and Israel Liberzon at the University of Michigan are examining whether being under chronic stress or having less responsive parents, two common features of growing up in poverty, lead directly to differences in brain structure and function in adulthood.
That information could help researchers and policymakers craft interventions to give children who live below the poverty line more of the advantages of their middle-class peers.
The study will examine a group of 52 young adults -- a subset of a group that Evans has been following closely over more than 15 years for another study. Of the subjects, half grew up below the poverty line and half grew up in working- or middle-class homes.
For the new study, the researchers will use functional magnetic resonance imaging (fMRI) and psychological and physiological tests to examine three key brain areas -- the hippocampus, prefrontal cortex and amygdala -- that are thought to be affected by childhood poverty.
If they find differences in the brain regions between subjects who grew up in poverty and those who didn't, the physiological and psychological data Evans has collected over the years will allow them to look specifically at the stressors each subject has been exposed to since childhood, and examine whether individual or cumulative stressors are linked to anatomical or functional differences.
The researchers will also use subjective reporting and physiological tests to examine whether parental responsiveness in childhood is linked to brain changes.
"There's a huge amount of data linking poverty to achievement, to mental health and to physical health; and some work showing that early chronic stress affects the brain," Evans said. "And there are certainly suggestions that parenting can affect the brain. So what we are doing is putting those together and looking at areas in the brain that have been shown or are suspected to be sensitive to chronic stress, as well as to parenting that's not ideal."
If the results indicate that the stressors of poverty do cause specific brain changes in early childhood, Evans said, policymakers could use that information to target social programs more effectively.
The results could also have cultural implications, he added.
"There is this widespread American belief that you can pull yourself up by your bootstraps; that you're responsible for what happens to you," he said. "This potentially challenges some of these notions, because if in fact you have had biological changes -- it's not necessarily that they're irreversible, so it doesn't mean you're doomed -- but it just means that maybe we have to think about these kinds of issues in a different manner."
Evans estimates that the stimulus funding will support about five jobs over two years. To date, researchers at Cornell's Ithaca campus have received 131 ARRA grants, totaling more than $105 million.