Personality could be regulated by the immune system

The study of Personality types it is one of the main areas of research in psychology.

Several proposals for personality tests and systems have emerged from it, very useful both in applied psychology and in research. However, still very little is known about what causes the appearance of the personality itself. We realize that there are differences in people's behavior (and thinking) patterns, but we do not know what their origin is. ¿Genetics?, ¿learning differences? The answer to this topic, in addition to being a mystery, seems to be very complex.

However, recent research has shed some light on the matter, and it has done so from a possible answer that is surprising. One aspect of our personality could be controlled by our immune system.

The origins of the gregarious personality

The conclusions of the study, which have been published in the journal Nature and are signed by several researchers from the University of Virginia, point to the possibility of that part of our social behavior has appeared under the influence that the immune system has on Our brain.

The research was carried out from the study of several laboratory mice in whose body there was a shortage of a molecule called gamma interferon (IFN-y). This element has a very important role in the immune response to pathogens, so it could be said that it fights against diseases.

But its relevance does not just stop there, judging by what was observed in the mice. These rodents se were significantly less sociable than the rest, and its behavior resembled what happens in cases of autism.

Furthermore, by placing these animals under observation using the functional magnetic resonance imaging technique, It was seen that some areas of the prefrontal lobe were much more activated than is normal in individuals of their species. This was illuminating, because the prefrontal lobe is known to play an important role in regulating behavior. social, and also calms the orders that reach the cortex from the limbic system, which is the part of the brain responsible of the appearance of emotions.

The immune system and molecules to be more social

Once this was observed, the researchers injected IFN-y into this group of animals and, right after, they watched his demeanor change to that of one more sociable mouse, completely normal.

In addition, they found that after introducing this type of molecule into the body of the mice, the amount of a neurotransmitter called GABA, responsible for, among other things, inhibiting the activation of many neurons in the prefrontal lobe. This caused the level of activity in this area to drop until it was within normal limits.

More studies, more evidence in favor

The same researchers conducted another type of study, this time from an evolutionary perspective, to see if the role of gamma interferon was as relevant as it appeared. To do this, they analyzed the genome of several animal species. In this way they discovered that those animals that had been sharing space with other members of their species were more predisposed to make the gene responsible for the manufacture of IFN-y to be expressed more, while the opposite happened with those that had been more isolated.

In other words, these different animal species were genetically programmed to produce more IFN-y to find themselves in social situations, even though they were not infected.

The implications of the study

The discovery made in this study is highly relevant for two reasons.

The first of them is that the most intuitive and apparently logical thing would be to think that it was social behavior that, increasing the spread of diseases, had effects on the immune system of our ancestors, and not the reverse. This research breaks with this idea by placing the immune system as a possible trigger for the onset of the sociable personality.

What's more, according to Jonathan Kipnis, one of the study's co-authors, the brain and immune systems were believed to function each by his account, and when immune activity was appreciated in the brain it was interpreted as a sign of disease. Therefore, knowing that certain immune components can have such significant effects on the brain opens the door to future lines of research that allow us to know more and better about human behavior and animal.