Your Facebook Profile Reveals More Than You Think

I recently attended a science writing seminar at Yale University led by Carl Zimmer, in which we were asked to read and write a summary regarding the article "Online social network size is reflected in human brain structure" by Kanai et al. (2011, published in Proc. R. Soc. B). This article brings up some interesting questions regarding how the new age of social networking technology might be affecting us; here's what I wrote:

The recent surge in social networking websites, with over 750 million subscribers to Facebook worldwide, has allowed people to rack up lots of online friends and make visible to others how large their networks are. But who would have thought that the number of Facebook friends you have could reveal more about you than just your popularity?

A group of neuroscientists and anthropologists in London and Denmark were curious to know if there is a biological basis for how people participate in online social networking. They thought that regions of the brain involved in social cognition and behavior could be important in determining the size of a person’s online social network. The researchers also thought that brain regions linked to memory capacity would affect network size, as the number of online friends a person has is usually much higher than the number of “real world” friends. 

 

Just a few months ago, Dr. Kanai and colleagues published their findings in the Proceedings of the Royal Society. Their report is the first scientific study to show a relationship between an individual’s online social network size and the size of parts of the brain that control social perception and associative memory.

The researchers came to these findings by studying magnetic resonance imaging (MRI) brain scans of over 100 volunteers from University College London, where the average participant age was around 23 years old. Dr. Kanai and colleagues measured the gray matter (the part of the brain containing all the neurons) density across the brain of each individual. The scientists focused on three regions: the right superior temporal sulcus, left middle temporal gyrus and entorhinal cortex, which are the parts of the brain that control social perception and associative memory. The density values for each participant were compared to his or her number of Facebook friends, and the scientists observed a trend between gray matter density in these three regions of the brain and the number of Facebook friends an individual has. So, if someone has a lot of Facebook friends, the gray matter density of his or her brain should be larger than someone who has fewer Facebook friends. 

 

But does this mean that you have a larger brain because you have more Facebook friends, or rather that you have more Facebook friends because you have a larger brain? This cause-and-effect distinction is still not clear to the scientists.

The scientists were also curious about comparing the size of an individual’s online and “real world” social networks. To do this, they gave a Social Network Size Questionnaire to a subset of the study participants, which asked details like: “How many people were present at your 18^th or 21^st birthday party?” and “What is the total number of friends in your phonebook?” From these questionnaires, the researchers saw a trend in which individuals who have a larger “real world” network have more Facebook friends than people with a smaller “real world” social group. The researchers also found that the gray matter density of the amygdala, another region of the brain important for social cognition, is linked to the size of both an individual’s Facebook and “real world” social network.

So how is all of this research useful? One example is that companies interested in hiring an individual will oftentimes examine his or her Facebook or a similar online profile, usually looking for photos or posts that can reveal information about that person’s character and personality. Maybe now companies should focus more on the number of Facebook friends a person has in order to gain insight into his or her social and memory skills.