Study Links Crime, Low Arousal Level

Some youngsters may be just a few steady heartbeats away from a life of crime, according to a USC study that links lower physical arousal traits with future lawlessness.

The study of juvenile delinquents found that if it takes more to make them sweat or speed their heartbeat, they are more inclined to continue a life of crime than juvenile delinquents with normal arousal rates.

“We think if you have low levels of arousal, you’re seeking out levels of stimulation to bring levels to normal. Some kids join a gang, burgle a house,” said USC psychologist Adrian Raine.

The study, which appears in the November issue of the American Journal of Psychiatry, focused on the autonomic nervous system, which controls functions such as heartbeat and perspiration.

Raine and two other researchers followed 51 English boys, beginning in 1978 at age 15. Two-thirds were juvenile delinquents, considered antisocial by their teachers while lacking criminal records. The remaining third were not considered delinquent.

Follow-up surveys showed that by age 29, 17 of the delinquents had criminal records and 17 delinquents had straightened out. The 17 non-delinquents had remained on the straight and narrow path.

Raine found that delinquents who turned to crime had heartbeats that were slower by an average of nine beats a minute than the delinquents who straightened out and the non-delinquents. They also had sweat rates that were three times slower than non-delinquents.

Raine said it was unknown whether the results stemmed from genetic or environmental factors. He suggested that “some sort of biofeedback training” could be used to raise arousal levels.

Dr. Dorothy Otnow Lewis, a psychiatrist and violence specialist at the New York University School of Medicine, called Raine’s work interesting but cautioned against using it to predict criminal behavior.

“That’s a very dangerous way to interpret these kinds of data because there are a lot of reasons why people’s autonomic nervous systems are more or less sensitive to the environment,” she said.