It's summertime. Children are out and about — swimming in pools, swinging at playgrounds, playing ball in the backyard. Given all the activity, someone will inevitably get hurt. One tot will push her way to the head of a line at the slide or another will decide it's his turn on the swing.
In his research on physical aggression, Carnegie Mellon's Daniel Nagin — a criminology expert and associate dean at our Heinz School for Public Policy and Management — has found that physical aggression peaks at about age 3, and then declines.
But a small group — about five percent — will remain highly physically aggressive.
"It's this group that accounts for an inordinate share of violent criminal behavior in adolescences and beyond," said Nagin, who recently won the Edwin H. Sutherland Award, the highest honor awarded by the American Society of Criminology for outstanding contributions to the field.
Nagin, who is fascinated by the question of why criminal and violent behavior is so persistent, developed a trajectory method to study the evolution of criminal behavior, which is described in his book "Group-Based Modeling of Development."
"Many of us have had the good fortune to be raised in families in which at least one parent made big investments in our emotional and cognitive growth." said Nagin. "Research demonstrates that such early investments pay big returns later in life."
For children not born into these circumstances, Nagin says the best way to reduce violent and criminal behavior in adolescence and beyond is to greatly expand the scope and availability of 'early life' programs for at-risk children.
The recipient of a $300,000 grant from the National Science Foundation (NSF), he plans to continue his work on trajectory modeling and on using his research to influence the design of crime-prevention policies.
Nagin has been a faculty member at the university for over 20 years. He earned his doctoral degree from the Heinz School and received his bachelor's and master's degrees from Carnegie Mellon. Both of his parents and three of his uncles are also alums, and he met his wife, Rise, while they were both students here.
Photographed: Dan Nagin, courtesy of the Pittsburgh Post-Gazette