Violent Offenders: Heartily Calm Before The Storm

2. November 2015
Share article

Young adults with a low resting heart rate, according to one study, have a significantly increased risk of becoming either violent offenders or victims of crime later in life. Will the measurement of heart rate prove to be a new tool in preventing violence?

In a study published in JAMA Psychiatry [Paywall] Dr. Antti Latvala and his colleagues from the Department of Epidemiology and Biostatistics at Karolinska-Institut in Stockholm, Sweden, evaluated data derived from 710,264 Swedish men. They were measured at the age of 18 years during compulsory suitability testing for the Swedish military service for, among other things, resting heart rate. By comparing this data with other official registers on crime, medical treatments and deaths from assaults and accidents, the researchers were able to establish the existence of a link between the heart rate at rest and an increased risk of crime and accidents. Numerous physical, cardiovascular, psychiatric, cognitive and socio-economic factors were taken into account in obtaining these calculations.

The average heart rate at rest was 72.2 beats per minute. Compared to men with a resting heart rate in the top quartile (≥ 83 beats per minute), the men with a pulse in the lowest quartile (≤ 60 beats per minute) had a 39% higher risk of getting sentenced for violent crimes. Moreover, they had a 25% greater likelihood of being sentenced for non-violent offences. Furthermore, men with low resting heart rate showed 39% increased risk of injury, both for injuries caused by a violent assault as well as accidental injuries. With one group of the men data had also been collected on cardio-respiratory fitness, taking this into account however had no significant impact on the results.

Criminals and victims: Two sides of the same coin

The JAMA Study is not the first on the relationship between resting heart rate and aggressive behaviour, however it is by far the most comprehensive of its kind – the number of cases is about 100 times greater than that of all previous studies. In addition, it was previously merely known that a lower resting heart rate among children and adolescents [Paywall] is associated with pronounced anti-social and aggressive behaviour. The theory that we are looking at a predictor for violence occurring more than 30 years later by looking at the heart rate during youth, on the other hand, is a new one.

An explanation for why adolescent resting heart rate is a risk factor for both violence and accidents in adulthood is not something the authors were however able to deliver in their longitudinal study. Basically, two models are presented: according to the so-called fearlessness theory [Paywall] low resting heart rate is a sign that a person experiences less anxiety. “Some people may commit crimes because they have no fear of the consequences of an arrest. A normal level of anticipatory fear keeps many of us from committing a crime”, declares Dr. Adrian Raine, a professor of criminology, psychiatry and psychology at the University of Pennsylvania, United States.

The other hypothesis however assumes that the resting heart rate is an expression of arousal state – individuals with low resting heart rate are therefore searching out stimuli [Paywall] in order to elevate their abnormally low level to a normal level. “Individuals who impulsively seek out stimulation could have a preference for a high-risk social environment and for making reckless decisions which make them vulnerable to assaults”, says Dr. Raine. “For some young people a path to greater arousal might be to join a gang or to instigate a fight”.

Prevention with heart

Worldwide, according to the United Nations Office on Drugs and Crime (UNODC), there occur each year more than four million documented cases of injury and more than 300,000 murders. Effective means for preventing aggressive behaviour are therefore urgently needed. Nonetheless, should essentially all minors be screened for their resting heart rates in order to identify potential perpetrators and victims of violence at an early stage, thus enabling timely preventive measures to be made? The self tracker could in this way unintentionally become a state control instrument.

Mitigating circumstances thanks to genetic testing?

There are indications that resting heart rate is to a substantial extent genetically defined. In addition, it was able to be shown that the association between a low resting heart rate and antisocial behaviour among children and adolescents can be fully explained by genetic covariation. However, the genetic determinants for heart rate are just one of many pieces in the puzzle dealing with the question of the genetic risk factors relating to psychopathological states. An abundance of genes had already been declared to have an impact on antisocial behaviour and aggression, particularly genes with influence on the serotonergic and catecholaminergic system have moved into the focus of research for some time. For example the “warrior gene”, which has acquired familiarity beyond the boundaries of the specialist world and whose X chromosome encodes monoamine oxidase A (MAO-A), plays an important role in the degradation of serotonin and noradrenalin in the central nervous system. Reduced MAO-A activity was ascertained in several [Paywall] studies to have an association with impulsivity and violent behaviour.

This raises the fundamental question of whether an offender’s genetic predisposition should be considered a mitigating circumstance in the determination of a punishment [Paywall], and whether precautionary measures should be taken against perpetrators with a corresponding predisposition so as to protect the society. A 2014 published meta-analysis concludes that none of the previously investigated gene variants is a reliable predictor for aggressive behaviour. It appears, therefore, as though one or a few genes cannot be held responsible for violence and crime. Instead, these are probably complex behaviours involving hundreds or thousands of genes and the environment interacting with each other. The authors of the meta-analysis therefore conclude: “Any approach in which genetic markers are used in order to make a risk prediction, to mitigate the responsibility for a crime, or to treat or define how to deal with certain individuals, is questionable. ”

Original publication:

A Longitudinal Study of Resting Heart Rate and Violent Criminality in More Than 700 000 Men [Paywall]
Antti Latvala et al.; JAMA Psychiatry, doi: 10.1001/jamapsychiatry.2015.1165; 2015

5 rating(s) (5 ø)

Comments are exhausted yet.

1 comment:

Guest
Guest

I know the article said the study claimed to take into account the fitness of the subjects and it made no difference to their conclusions but what about “extreme fitness”? When I was 18 I was running 70-100 miles per week as a competitive distance runner and had a resting heart rate of 54. I still have numerous friends from that time that fit that same category and none of us has fallen into the violent crime/criminal group.

#1 |
  0


Copyright © 2017 DocCheck Medical Services GmbH
Language:
Follow DocCheck: