A new study suggests that young men who have a low heart rate are most likely to exhibit criminal behaviors when they become adults. Antti Latvala, study author and a postdoctoral researcher at the department of public health at the University of Helsinki in Finland, and her colleagues looked at the criminal records of more than 700,000 Swedish men between 1973 and 2009 and compared it to their recorded heart rates at age 18.

Heart rate is the number of times the heart beats per minute. The normal or resting heart rate is between 60 and 100 beats per minute.

Initial analysis showed that the most common violent crimes include murder, assault, kidnapping, robbery and rape, while the nonviolent crimes are drug dealing, theft and some traffic violations. Nearly 40 percent of those with a low heart rate were more likely to commit violent criminal behaviors compared to those with a high heart rate. Those with a lower heart rate are 25 percent more likely to commit nonviolent crimes as well.

The researchers admitted that further study is needed to explain how low heart rate makes one more violent or risk-taking.

"It is obvious that low resting heart rate by itself cannot be used to determine future violent or antisocial behavior," Latvala told Reuters Health by email. "However, it is intriguing that such a simple measure can be used as an indicator of individual differences in psychophysiological processes which make up one small but integral piece of the puzzle."

Adrian Raine, a researcher in criminology and psychology at the University of Pennsylvania in Philadelphia who also wrote an accompanying editorial for the study, agrees that the study provides a strong link between heart rate and criminal behaviors. However, he warned parents not to panic if their children have low heart rate.

"There are many things that contribute to violence, not just biological factors like heart rate," Raine said to HealthDay News. "Yes, having a low heart rate raises the odds of committing a crime, and not just violent crime, all kinds of criminal and reckless behavior. But it doesn't mean that you will."

The study was published in the Sept.9 issue of JAMA Psychiatry.