The amount of friends could be predicted by the size of our amygdala, a part of the brain in the form of small almond. So says an article published in the journal Nature Neuroscience. Thanks to previous studies, it is known that the amygdala is involved in personal issues such as the interpretation of emotional facial expressions, visual or react to threats in the trust given to strangers.
Comparisons between different species of nonhuman primates have shown previously that amygdala volume is associated with the number of individuals in the group, suggesting that this region of the brain supports the skills needed for complex social life.
Based on these results, the psychologist Lisa Feldman Barrett, Northeastern University in Boston, Massachusetts, has studied whether it also the case in humans. To that end, his team measured the volume of the amygdala in 58 healthy adults, using brain scans taken during MRI sessions and asked for specifics about the social networks to which they belonged.
Feldman Barrett’s team found that participants with social networks larger and more complex had large tonsils. According to these scientists, this effect does not depend on the age of the volunteers, their own perception of their social or life satisfaction, suggesting that happiness is not the underlying causal factor linking the size of this brain structure an individual to his many friends.
However, it remains a mystery how the amygdala contributes to social networks. Brad Dickerson, a cognitive neuroscientist at the Massachusetts General Hospital in Boston and helped lead the study, said it is likely that social behavior is based on a much wider broad regions of the brain.
Another important issue is whether a large amygdala is a cause or a consequence of having a wide network. Kevin Ochsner, a cognitive neuroscientist at Columbia University in New York, believes it is likely that there may be both.