Studies have established a link between antisocial behaviour and heart rate.  It was found out that teens that have low resting heart rates earlier in life are likely to manifest antisocial behaviours later in life. 

According to a Swedish study published Wednesday in JAMA Psychiatry, researchers suggest that a low resting heart rate which is less than or equal to 60 beats per minute is associated with antisocial behaviour and can be an indicator who among young men are more likely to commit violent crimes later in life.  In the study, researchers analyzed information from more than 710,000 men who had their heart rate measured when they were 18 years old, as part of a test for military service in Sweden. 

According to Newsweek, researchers at Karolinska Institutet, Stockholm and University of Helsinki looked at data from military enlistment of Swedish men born between 1958 and 1991 with an average of 18 at the time of enlistment.  The data included were their heart rate and blood pressure.  A total of 40,043 men in the group who had a violent conviction at some point later in life based on the follow-up data collected after three decades. 

The researchers then divided the men into five groups according to their hear rates.  Men in the group with lowest resting heart rate (60 beats per minute or less) were 39 percent more likely to be convicted with violent crime compared to men in the group with the highest heart rate (83 beats per minute or more).  These crimes can probably be murder, assault, robbery, arson among others.  Those men whose hear rates were lowest are also found to have a 25 percent higher chance to be convicted for a nonviolent crime such as drugs or traffic offense.

The researchers also considered factors that might affect heart rate such as the men's height, weight, cardio-fitness level and factors that might influence a person for committing a crime such as his socioeconomic status.  Previous studies have also linked low resting heart rate to antisocial behaviour in children and adolescents.  It was suggested that teens are seeking stimulating experiences or that they fail to recognize danger as opposed to their peers with normal hear rate.

"It is obvious that low resting heart rate by itself cannot be used to determine future violent or antisocial behavior," Antti Latvala, one of the researchers said by email to Reuters. "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."