Aggressive boy behavior: 'epigenetic changes may be a cause'

Researchers say that chronic aggressive behavior found in some boys may be a result of epigenetic changes during pregnancy and early childhood, according to two studies published in the journal PLOS ONE.

Both studies were led by Richard E. Tremblay of the University of Montreal and Moshe Szyf of McGill University.

For the first study, the team analyzed the blood samples of 32 male individuals from Quebec with a disadvantaged background, who had suffered from chronic physical aggression since childhood.

The males were selected from two longitudinal studies, conducted by Prof. Tremblay's team, that spanned almost a 30-year follow-up period, following the participants from childhood to adulthood.

Alongside this group, the team also examined the blood samples of a group of males from the same background, but who did not suffer from chronic aggression.