As is well known, the majority of crimes, including violent ones, are committed between the ages of 15 and 25, after which the criminal activity of individuals declines, if it does not cease entirely. There are even claims that such a link between age and crime is universal across different groups of people and societies, meaning this phenomenon has a strong biological determination. The decline in criminal activity with age is often linked to the formation of the nervous system and the development of emotional control.
For a full understanding of the topic under consideration, it is worth mentioning one important biological factor. The average healthy individual possesses a violence inhibitor, which triggers a rejection reaction toward causing harm to other people. Of course, its function develops with age, but this process can already be observed at the age of 4-7; as an unconditional reflex that automatically activates when observing distress signals (expressions of sadness, fear, pain), the violence inhibitor is present in humans from birth.
Obviously, the commission of violence requires that the violence inhibitor function in a person be impaired or suppressed. However, it is very important to note that such an impairment does not provoke violence on its own. It only means that there is one fewer deterrent against committing violence. And this is where social factors come into play, which mediate the link between age and crime. Their list is as follows:
– over time, criminals begin to realize that their activities do not provide much benefit compared to the risks they take and the effort expended;
– with age, people strive to “settle down,” and the negative influence of peers in youth is later replaced by social disapproval;
– as they age, criminals may lose partners for committing crimes due to death, imprisonment, or loss of trust in them;
– the decline of physical abilities due to aging makes crime a more dangerous and less successful occupation;
– the propensity for crime is reduced by life experience, the loss of aspirations that require it, or the acquisition of legal methods for satisfying those aspirations.
As we can see, many social circumstances make crime less profitable in the eyes of the criminals themselves over time. But there are also circumstances that can bring back violent urges. There is a common belief that in the Rwandan genocide, the bulk of the violence was committed by young people aged 19-20. However, as data shows, the main perpetrators of violence were men over 30. The median age of all perpetrators during the genocide was 34. And only a third of them were involved specifically in violent crimes.
It is also worth mentioning that aging is often associated with neurodegenerative processes, and this can contribute to increased aggression. An example can be found in those suffering from Alzheimer’s disease. Particular attention should be paid to the functioning of their serotonergic system, which is responsible for the violence inhibition mechanism. Research links the impairment of its function to the increased aggression observed in Alzheimer’s patients who have a reduced density of serotonin 1A receptors. Meanwhile, aggression remains at a low level in those patients whose 1A receptor density is not reduced.
It can be concluded that the link between age and criminal activity, including violent activity, is mediated not by biological, but by social factors. Most individuals are not prone to it due to a sufficiently expressed violence inhibitor. But those in whom a deficiency can be observed are dependent on environmental influence in the manifestation of their violence. And certain social factors can incite them to violence at any age. Also, it seems that these individuals risk manifesting increased aggression due to aging and neurodegenerative diseases, however, it should be noted that this can rarely evolve into actual criminal activity due to their condition and age.
