Parts Of Brain Correspond To Facebook Friend Lists

A scientific study has found that people with lengthy or complex friend lists on Facebook have correspondingly larger amygdalas in the brains, along with noticeable differences in parts of the cerebral cortex.

People with large or complicated lists of friends have correspondingly larger amygdalas within their brains, according to a scientific study.

This study, “Amygdala volume and social network size in humans,” appears in the journal Nature Neuroscience.

Kevin C. Bickart of Boston University School of Medicine’s department of anatomy and neurobiology and a team of researchers compared the size of different regions of the brain with the corresponding individuals’ social networks.

One part of the brain that the scientists studied, the hippocampus, didn’t show any correlation with the use of social networks. But the amygdala did. Three subregions of the cerebral cortex also showed some noticeable differences among the socially well-connected.

We found that amygdala volume correlates with the size and complexity of social networks in adult humans. An exploratory analysis of subcortical structures did not find strong evidence for similar relationships with any other structure, but there were associations between social network variables and cortical thickness in three cortical areas, two of them with amygdala connectivity. These findings indicate that the amygdala is important in social behavior.

This research offers a significant breakthrough in scientists’ ongoing effort to figure out exactly what the amygdala does. Google the term and you’ll find that this region of the brain controls memory and emotional reactions. That certainly jibes with having a large or complex friend list.

The cerebral cortex’s connection with large or complex friend lists seems less clear in the study’s findings, but that may be consistent with what this part of the brain does. Wikipedia says this area gets involved in memory, attention, awareness, thought and consciousness. The first of these strikes me as most relevant to Facebook.

What do these findings, including the charts from Nature Neuroscience below, portend for people looking to better leverage Facebook? Do you see anything in this study that might help marketing types in particular?