Can Facebook Boost Your Social Brain?

This is your brain on Facebook

Posted Jan 31, 2012

To understand these findings, it would help to know about the amygdala, the brain structure that's related to social network size. The amygdala is an interesting little part of the brain that is ordinarily thought of as involved in fear, anxiety, anger, and even the personality trait of psychopathy involved in antisocial personality disorder. People who have explosive anger outbursts are thought to have overly large amygdalas, for example.  Conversely, people with antisocial personality disorder have ones that are too small making it hard for them to learn to associate negative outcomes with the criminal behaviors that may land them in jail.   

At any rate, the amygdala is in fact usually associated with negativity, but it also plays a role in positive social relationships. A Boston University research team headed by Kevin Bickart wrote in a recent Nature Neuroscience article (Bickart et al., 2011) that the "corticobasolateral complex" within the amygdala connects with other structures known in popular terms as the brain's "social network."

Most of the research studying relationships between the brain's social network and social behavior has been conducted on primates in the lab. Bickart and his collaborators decided to test the hypothesis on "a single primate species, humans." They compared the size of this region of the amygdala with two measures of social network: size and complexity.  As you might expect, size equaled the number of regular contacts that a person maintains. Complexity equaled the number of different groups these contacts belong to.  

The Social Network Index that Bickart and colleagues used was developed in 1997, well before Facebook came about. It assesses participation in 12 types of social relationships including those with spouse, parents, parents-in-law, children, other close family members, close neighbors, friends, workmates, schoolmates, fellow volunteers (eg, charity or community work), members of groups without religious affiliations (eg, social, recreational, or professional), and members of religious groups. One point is assigned for each type of relationship (possible score of 12) for which respondents indicate that they speak (in person or on the phone) to someone in that relationship at least once every 2 weeks. The total number of persons with whom they speak at least once every 2 weeks (number of network members) was also assessed. The social network measures, then, included both in-person and virtual relationships.

The main analysis in the Bickart et al. study consisted of assessing the relationship between amygdala size and these two social network measures, controlling for such factors as head size, and the size of other brain regions. They also examined other social relationship measures, including perceived social support and life satisfaction. To their credit, the researchers also separated the participants into groups based on their age because older adults actually have lower amygdala volumes than do younger adults.

There was a strong positive relationship between amygdala size and social network size and complexity but the findings varied by age and gender of participants. Among the older adults, only the left amygdala showed the positive relationship. For women, left amygdala size correlated only with social network complexity.  Men showed a more positive relationship between right amygdala size, both with network size and complexity. These differentiations don't change the overall results, but add some tantalizing ideas that would require further testing.

It wasn't just the amygdala that seemed related to social network size and complexity. The rest of the brain's social network was larger in people who had more friends and more complex groupings among their friends.

Now that you've heard the results, the refrain "Correlation does not equal causation" must be playing in your head though probably not in your amygdala. If you've been properly raised to think critically about psychological findings, you've already started to think about alternative explanations. Of course, this distinguished group of researchers had the same thought. It's possible that larger social networks help the brain grow in size and connectivity over a person's life. It's also possible that people who have larger social brain networks seek out more and deeper relationships with other people. There could also be a third factor such as social intelligence that may lead individuals with larger social brain networks to be more adept at managing complex relationships.

To summarize, knowing about Facebook's possible benefits for your brain, here are the 3 takeaway tips:

1. An extensive social network can benefit your brain's social circuitry, so don't feel guilty as you add new Facebook friends or Twitter contacts.

2. Other primates don't use online social media, so some of the effect of relationships on the brains of these other primates by necessity involved face-to-face not facebook-to-facebook time. Try to balance your online with your in-person friendships.

3. Keep an open mind to the online activities of your children, friends, co-workers, and other relatives and how they affect them. On the other hand, it's important to remain vigilant against social media addiction and related problems such as cyber-bullying and other Facebook "sins."

We need more studies on humans such as the one conducted by Bickart et al.  If those studies continue to produce supportive evidence, we may find that the best way to boost your brain's social power is by boosting your online social relationships.

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Copyright Susan Krauss Whitbourne, Ph.D. 2012


Bickart, K. C., Wright, C. I., Dautoff, R. J., Dickerson, B. C., & Barrett, L. (2011). Amygdala volume and social network size in humans. Nature Neuroscience14(2), 163-164. doi:10.1038/nn.2724

Miller, G. (2011). The brain's social network. Science334(6056), 578-579. doi:10.1126/science.334.6056.578