People who have a larger amygdala – the part of the brain that controls emotions – have a richer and more varied social life than people with smaller amygdala sizes, according to a study published in the journal Nature Neuroscience.
Such conclusions were reached by researchers from Massachusetts General Hospital (MGH) and Harvard University in Boston, who studied 58 healthy people aged 19 to 83 years. By means of questionnaires, information was collected on the number of friends they have and their affiliation to various social groups. They then measured the volume of different parts of the brain using MRI, including the amygdala.
It is an tonsil-shaped structure included in the so-called the limbic system – the oldest part of our brain in evolution. The amygdala controls emotional responses that are beyond our conscious control. It also includes negative emotions like anger and fear.
It turned out that people with a larger amygdala had a more extensive and varied network of social contacts. This relationship was independent of the age and sex of the respondents – comments Bradford C. Dickerson, who participated in the study. Moreover, it was specific to the amygdala – the volume of any other structure examined did not correlate with the number and complexity of social contacts.
However, it was not observed that the volume of the amygdala was related to other elements of social functioning, such as, for example, subjectively assessed support from others or satisfaction with social life.
These results are in line with the hypothesis that the amygdala has evolved with the development of human social life so that we can deal with increasingly complex group relationships, emphasizes Dr Lisa Feldman Barrett, lead researcher. It is also confirmed by previous observations that primates, which create more complex social relationships, have a proportionally larger amygdala in relation to the entire brain and body.
Humans, like other primates, are social animals by nature – we play, work, eat, and fight with each other. The larger amygdala allowed us to identify, learn, and recognize social and emotional cues in other members of our species, allowing the development of complex cooperative and competitive strategies, the authors wrote.
The researchers also hope that in the future their research will help to develop ways to help people with neurological or mental diseases who suffer from social behavior disorders. (PAP)