The neurological basis of aggressive behavior

What neurobiological indicators are consistent with violent behavior?

Every day in the media there are scandalous cases of crimes, aggressions and excessive violence. crimes, aggressions and disproportionate violence. Today we know that the environment in which a person grows and evolves and the same systems that shape it directly condition their development, but what if we ask ourselves what happens at the neurological level for a person to develop more aggressive behavior than another raised and educated in the same environment? In this article we answer this question

An aggressive person shows activity in certain areas of the brain

The hypothalamus, testosterone and serotonin have been the main avenues of research in relation to aggression for years, but today we can say that the following are some of the most important ones different works have shown how the stimulation exerted on the amygdala activates aggressive emotional reactions in the subject, as well as their inhibition when acting on the prefrontal cortex.and inhibition of these reactions when acting on the prefrontal cortex.

At the ontological level, the maturation of the prefrontal cortex is later than that of the amygdala, which means that the individual acquires the necessary skills for abstract reasoning, for changes in the attentional focus or even for developing the capacity to inhibit inappropriate responses, such as the control of aggression, among others.

The greater the volume of the prefrontal cortex, the less aggressive behavior.

Already in the late 1990s it was suggested that increased activity in the amygdala led to increased negative behaviors, including increased aggression, whereas decreased activity in the prefrontal cortex offered less ability to exert control over one's emotions.

It was a study conducted by Whittle et al. (2008) in adolescents, which finally concluded that the greater the volume of the prefrontal cortex, the less aggressive behaviors were perceived in the boys and conversely in the case of the amygdala, a larger volume responded to more aggressive and reckless behaviors at the same time.

When Anthony Hopkins plays the character of Hannibal Lecter in Silence of the LambsThe white matter in the prefrontal cortex, shows an unusual temperament for a murderer, far from transmitting an impulsive and emotional personality, stands out for having a calculating, cold and extremely rational profile, which escapes the explanation we are offering.

The white matter in the prefrontal cortex and its relation to aggressiveness

So far we have seen how an increase in amygdala activity and a decrease in the prefrontal cortex is ideal to describe a more impulsive personality, not very reflective and even with little capacity for emotional management, but how can we explain the typical characteristics of Hannibal?

In 2005, Yang et al. found that a decrease in the white matter of the prefrontal cortex corresponded to a decrease in one's own cognitive resourcesThe results of this study show that Hannibal's behavioral characteristics are not only a result of a decrease in the white matter of the prefrontal cortex, but also of a decrease in the ability to persuade or manipulate others, and to make decisions at specific moments. Keeping the white matter intact would explain why Hannibal and other killers with the same characteristics are able to control their behavior so masterfully, to make the right decisions in complex situations, always for their own benefit and even to the point of outwitting authority.

Serotonin is key to understanding aggressive behavior

As we said at the beginning, serotonin also plays a fundamental role in this subject, in particular, a decrease in its activity is directly related to aggression and the initiation of aggressive behaviors. and with the initiation of risky behaviors. In 2004, New et al. showed that treatment with SSRIs (selective serotonin reuptake inhibitors) increased the activity of the prefrontal cortex, and after one year the aggressive behaviors of individuals were considerably reduced.

In summary, we can remark how an increase in serotonergic activity would increase the activity of the prefrontal cortex, which would cause the inhibition of amygdala activity and consequently aggressive behaviors.

We are not slaves of our biology

Although we know that the brain is not the determining factor in the modulation of aggression and these behaviors by itself, it is thanks to advances and numerous studies that we can explain its mechanism as far as the neurological process is concerned. Guido Frank, scientist and physicist at the University of California points out that biology and behavior are susceptible to change and that, by combining and that, by combining a good therapy process and adequate individualized control, the progress of each individual can be modified.

Ultimately, as the neurologist Craig Ferris of Northeastern University in Boston, USA, points out, we must keep in mind that "we are not completely slaves to our biology".