Children who grow up in poor families may have smaller
brains than their more well-off peers, says a new study. But good parenting may
help overcome that disadvantage.
Researchers found that kids who grew up poor tended to have
smaller hippocampus and amygdala volumes. Those areas of the brain are partly
responsible for regulating memory and emotions. "Generally speaking, larger
brains within a certain range of normal are healthier brains," Dr Joan
Luby, the study's lead author, said. "Having a smaller brain, within a
certain range of normal, is generally not healthy. It's associated with poorer
outcomes," Luby told Reuters Health.
She is a professor of child psychiatry at the Washington
University School of Medicine in St Louis. Prior studies looking at poverty and
brain size found similar patterns. But Luby and her colleagues also wanted to
look at what may bring about brain changes.
They found kids tended to have smaller brains when they had
experienced stressful life events or when their parents were hostile or unsupportive.
The new findings give parents and researchers a "very specific and
changeable" target, Luby said.
For their report, published in JAMA Paediatrics, she and her
colleagues used data from an existing study of 145 children from in and around
St Louis. The children were between the ages of six and 12 at the time their
brains were imaged. They had been followed since preschool with annual
The screenings included tests for stress and whether or not
the children had entered puberty. At one session, parents and their children
were observed together and the researchers assessed parenting styles. They
found children from poor families tended to have smaller brains. But stressful
life events and a lack of parental support in family interactions explained
some of that link.
The study can't prove poverty or parenting caused the
changes in brain size. But the findings suggest that the chance poor children
will have smaller brains may be reduced with supportive parenting, Luby said.
She added that kids would do best with parents who are
sensitive, nurturing, attentive and emotionally available. "It's not as if
those affluent families are protected from these same (parenting) issues,"
Charles Nelson, who wrote an editorial accompanying the new study, said.
"The reason it's probably more common in poorer
families is that they're lacking in resources and trying to make ends
meet." There is a level of background stress... that may keep them from
being the parent they want to be," Nelson told Reuters Health. He is a
professor of paediatrics at Harvard Medical School and Boston Children's
Nelson said the findings are limited by the fact that many
children in the study were depressed or at high risk of depression. That may
influence the results. But he said the new study adds to what is already known
about poverty and childhood brain development.
Luby said it will be important to find out what
interventions – such as early preschool programmes, for instance – may encourage
a healthy environment for the developing brain. "Biology is very much
influenced by the environment," she said. "The question is what period
might be the time when the brain is most sensitive to influence."