Within psychology and neuroscience, some theories examine whether the brain's structure and function can influence criminality. Research has identified links between impairments in frontal, temporal, and subcortical brain regions and difficulties with behavioral control, emotional regulation, and social interaction.
The frontal lobes and executive functions
The frontal lobe is especially important because it helps us plan, make decisions, and control impulses. If this part of the brain functions less effectively, it may become harder to think through consequences and stop impulsive reactions.
The frontal lobes are closely related to executive functions: the ability to plan, maintain attention, control impulses, and adapt behavior to a situation. If these functions are impaired, it may become harder to organize schoolwork, follow rules, or handle frustration.
ADHD, school failure, and crime
Difficulties with executive functions are common, for example, in ADHD. People with ADHD may struggle with attention, planning, and impulse control, which can make school demands and later working life more difficult to manage.
Research shows that people with ADHD are more likely than others to face school failure, unemployment, and addiction-related problems. These factors are in turn linked to a higher risk of criminality. At the same time, this does not mean that most people with ADHD commit crime. The issue is statistical association, not the diagnosis itself causing criminality.
Many of these risks also decrease with the right support and treatment. Researchers further emphasize that people with ADHD often have strengths, such as creativity, energy, and idea generation.
Brain injury and social behavior
There are also theories connecting brain injuries to criminality. Studies have shown that people who commit crimes more often report earlier head injuries or loss of consciousness. But it is difficult to determine cause and effect. People who already display aggressive behavior, for example, may also be more likely to end up in fights and therefore suffer head trauma.
Damage to the frontal lobe can make it more difficult to control impulses, understand social norms, or think through consequences. The temporal lobe also matters because it is linked to empathy and the ability to interpret other people's emotions.
Empathy, dementia, and psychopathy
Studies of frontotemporal dementia show how changes in the brain's frontal regions can affect empathy. When patients with this illness are shown images that normally evoke compassion, the same brain activation seen in healthy people does not appear. This suggests that brain changes can influence how we respond to the suffering of others.
Similar questions also arise in research on psychopathy, where limited empathy and difficulty responding to the suffering of others are central themes.
Intelligence as a risk or protective factor
The link between IQ and criminality is weak. Meta-studies show that intelligence explains only a small part of the variation in criminal behavior. Social factors, such as upbringing and life conditions, often show much stronger relationships.
At the same time, research suggests that high cognitive ability and psychological resilience can function as protective factors. The ability to think clearly, handle stress, and cooperate with others may reduce the risk of criminality, even in vulnerable environments.
Brain changes may affect behavior, but criminality rarely emerges from one neurological factor alone.
Sources: Granhag, P. A., Stromwall, L. A., Ask, K. & Landstrom, S. (2021). Handbook of Forensic Psychology. Liber. Howitt, D. (2002). Forensic & Criminal Psychology. Pearson Education. Karolinska Institutet News, forskning.se, and NeuroPsykologi.org as cited in the source material.
