Back in August 2007 I was thrown into a small circle of people who were combating each other using something they referred to as 'Facebook zombies'. People worldwide were apparently biting each other online to increase their zombie armies. But the competition was a local one, too. Newcomers like me who had never heard of Facebook, let alone Facebook zombies, presented excellent opportunities for the local competitors to increase their online militia. To humor them I accepted the invitation to join Facebook and the zombie war.
That was my Facebook baptism. Soon enough I became a highly competitive zombie warrior and habitual Facebook user. As I sank my virtual teeth into people to amplify my armed forces, the number of my Facebook friends increased. At first Facebook was just fun and games: I would build snowmen, fight zombies, buy people fish for their aquariums, purchase furniture for my online apartment. Few people I knew had joined Facebook back then. Some signed up only because of my zombie invitations. I am sure most of the people I invited only enlisted to humor me. But I didn't really care. It was an enjoyable way of wasting a couple of hours late at night.
The newness and excitement of the puerile games slowly subsided. If you ask me today, I would honestly say that I have no idea whether these game and gift apps still exist. I stopped using them. But I stayed on Facebook. In the years to come philosophers I knew, old class mates and distant relatives joined the rapidly growing social networking site like crazy. The number of my Facebook friends grew steadily into the hundreds. My reasons for being on Facebook changed. It became a good way to share photos and stay in touch with people without having to do too much work.
When I reflect on my "chance entry" into Facebook and the slow development into what is in it for me now, I would insist that my being on Facebook and the size of my Facebook friend list have nothing to do with my personality and certainly nothing to do with my brain. Yet science tells us otherwise. According to a study published in the October 2011 online issue of Proceedings of the Royal Society B: Biological Sciences, there is a significant correlation between the size of certain brain regions and number of Facebook friends. The greater the number of your Facebook friends, the greater the size of the amygdala, the right superior temporal sulcus, the left middle temporal gyrus and the right entorhinal cortex. Previous research has shown a correlation between the size of the amygdala and real-world social network sizes. The researchers chose to look at Facebook friends because there is less of a tendency to friend people here for marketing purposes compared to other popular social networks.
The researchers emphasize that the study does not reveal any underlying mechanisms or causes. Even if the correlations are taken to be indicators of causal relations, it is unclear what causes what. Do parts of your brain grow as your list of Facebook friends get longer? Or do the larger brain regions make you more likely to add friends or accept friend requests?
Though I am somewhat skeptical that the correlations demonstrate any causal relationships, it might be fun to speculate a bit about what kinds of causal relationships the correlations could be indicative of. For starters, we might look at some of the functions typically associated with the implicated brain regions. The amygdala is that little almond-shaped region in the temporal lobe (the thumb of the brain) that typically is associated with fear processing and fear-induced memories. One interesting thing about this region is that it appears to be enlarged in people who suffer from anxiety disorders (see references below). Apparently when the increased activation is allowed to continue over time, it can cause the tissue in the amygdala to grow. There are likely other reasons for enlargement of the tissue in the amygdala than prolonged fear and anxiety, for example depression, stress, autism and bipolar disorder. But it is a real possibility that those of us who accumulate the most Facebook friends have a bunch of anxiety issues. A depressing thought. Another, perhaps more depressing and wildly speculative, interpretation of these data is that people with few Facebook friends are fearless and unemotional creatures with smaller than average amygdalas.
The other three brain regions that were found to correlate in size with the online social network size seem to play some role in social cognition. The right superior temporal sulcus is that fold that separates the middle and superior temporal gyrus in the temporal lobe. That plays a role in interpreting what people are paying attention to on the basis of gaze direction, hand gestures and mouth movement. The left middle temporal gyrus may play a role in the recognition of facial expressions. Finally, the right entorhinal cortex appears to play a role in associative memory. Individuals with an enlargement of these areas may be more efficient than others in detecting the sentiments and fervors of others.
So are people with loads of Facebook friends anxiety-ridden hermits highly attuned to the attitudes and passions of others? Well, perhaps. Perhaps the need for a large online social network is based on a heightened sensitivity to one's status in certain circles of colleagues, friends and acquaintances. This is not an unlikely interpretation. The researchers of the study suggest a different explanation. They speculate that the relatively larger amygdala found in people with scores of Facebook friends is due to the possible role of the amygdala in social cognition. However, I think this is a stretch. It has indeed been shown that people with impaired amygdala function have difficulties recognizing emotional facial expressions. But the likely explanation for this latter correlation is that an inability to process fear impacts the ability to process negative emotions in others. This doesn't demonstrate that the amydala is involved in social cognition, except in a very indirect way.
The researchers hesitantly conclude that the size of your Facebook network may be indicative of good social cognitive skills. But as they themselves point out, there was no correlation between size of Facebook friends and brain regions crucial to social cognition, such as areas involved in mirror mechanisms, perspective-taking and mentalizing. It is also worth emphasizing that friending people on Facebook bears little resemblance, behaviorally speaking, to exercising good social cognitive skills, as we normally understand these skills. My impression is that these virtual friendships in many cases take away the need for real-world friendships and the need for being able to interpret people's intentions on the basis of standard cues, such as facial expressions, body movements and posture. Personally, I find it a whole lot easier to be a social person online than in real-life settings, exactly because I don't have to engage in the interpretive exercises required to understand people in face-to-face settings or provide the subtle cues required to make people avoid misinterpreting my behavior in real-life social settings. If you get sick of looking at someone on Facebook, you close the computer. If you get sick of having your friend hang out on your couch and not getting the hint that you would like her to leave, you don't just discreetly lock yourself into the bathroom until she gets the hint. I suspect interacting with people on Facebook is a bit like interacting with people at a large university reception. You engage in small talk with a few people at a time, then you move on. If you need a break, you can move over to the food bar and talk to the carrots. A bare minimum of social skills will get you through the night. A perfect forum for those (of us) who are socially lazy.
1. R. Kanai, B. Bahrami, R. Roylance, G. Rees. 2011. Online social network size is reflected in human brain structure. Proceedings of the Royal Society B: Biological Sciences, Oct 2011. http://rspb.royalsocietypublishing.org/content/early/2011/10/12/rspb.2011.1959.full
2. Bickart K. C., Wright C. I., Dautoff R. J., Dickerson B. C., Barrett L. F. 2011 Amygdala volume and social network size in humans. Nat. Neurosci. 14, 163–164
3. A.A. Ellen. 2010. Amygdala volume correlates positively with fearfulness in normal healthy girls, Social Cognitive and Affective Neuroscience 5: 424-431
4. C. Lange, E. Irle. 2004. Enlarged amygdala volume and reduced hippocampal volume in young women with major depression, Psychol med 34: 1059-64
5. B.K. Holzel, et al. 2010 Stress reduction correlates with structural changes in the amygdala, Scan. http://scan.oxfordjournals.org/content/5/1/11.full.pdf
6. W. Groen, M. Teluij, J. Buitelaar, I. Tendolkar. 2010. Amygdala and hippocampus enlargement during adolescence in autism, J Am Acad Child Adolesc Psychiatry 49:552-60.7. B.K. Chen, et al. 2004. Cross-sectional study of abnormal amygdala development in adolescents and young adults with bipolar disorder, Biological Psychiatry 56: 399-406