A link between social network size and brain structure?

A macaque grooming her offspring. An image that illustrates how macaques form relationships. Noah Snyder-Mackler The more social relationships we have, the more certain structures in our brain are developed. This has been the hypothesis of various neuroscience research projects for several years. With previous findings having highlighted the role of our social environment as one of the key factors behind the expansion of the cerebral cortex, researchers from Inserm and Université Lyon Claude Bernard Lyon 1, in collaboration with the University of Pennsylvania, went one step further in elucidating this link. They were more specifically interested in a species of macaques whose brain architecture is comparable to that of humans. By observing these non-human primates in their natural state and by analyzing images of their brains, they discovered that the number of companions they have is predictive of the size of certain brain regions associated with social cognition and empathy.