"We think that when the difference is actually less than it usually is among boys -- but not girls -- this contributes to some mental health problems and, perhaps, aggressiveness," he said.
"But there's relatively little research -- almost none -- that shows a relationship between brain structure and actual behavior," Allen added. "So we can't say what the direction of causation is. It could be that environment has influenced teen brain structure. Or that brain structure is influencing their relationship behavior with the parents. Or it could be both. More and more, I think we are realizing that it's not a matter of a simple equation. It's a question of an interaction of both environment and biology. But we don't yet know how these two areas interact."
Elliott Albers, director of the Center for Behavioral Neuroscience at Georgia State University in Atlanta, agreed that many key questions remain.
"This study is very interesting and consistent with prior animal studies which support the concept that there are changes in limbic structures that can potentially relate to aggression," he said.
"However, we still don't know if conflict causes physical changes -- whether the social experiences of boys and girls cause different changes in their limbic system that can affect aggression -- or whether it's the other way around. Frankly, we still don't know much about what causes the neuroscience of aggression," Albers said.
For more on the adolescent brain, visit Bryn Mawr College.
SOURCES: Nicholas Allen, Ph.D., associate professor, Orygen Research Centre, University
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