While I applaud the work that is looking at the biochemical correlates of aggressive and delinquent behavior, it is important to emphasize that environmental factors still predominate when we are searching for the roots of violence. Although there is no single factor underlying aggressive behavior in children, my own 30-plus years looking into the relationship between excessive parental discipline and delinquency has convinced me that the violent, recidivist, male juvenile delinquent who was not raised on the belt, board, cord, or fist is nonexistent.

Ralph S. Welsh
Danbury, Conn.