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Brain & Nervous System Health Center

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Is Facebook Changing Our Brains?

Number of Facebook Friends Linked to Brain Variations
By Peter Russell
WebMD Health News
Reviewed by Keith Barnard, MD

Oct. 19, 2011 -- Scientists in the U.K. say they have found a strong link between the number of friends people have on Facebook and how "brainy" they are -- namely, the amount of gray matter in particular regions of their brains.

The researchers from University College London (UCL) also discovered that the more friends people have on the social networking site, the more friends they are likely to have in the "real world."

However, writing in the journal Proceedings of the Royal Society B, they stress the study shows an association and not cause and effect. In other words, are people with more gray matter in parts of the brain more social online and off, or did the brain matter change as a result of getting involved in social media?

Geraint Rees, PhD, a Wellcome Trust Senior Clinical Research Fellow at UCL, says in a news release, "It is not possible from the data to say whether having more Facebook friends makes the regions of the brain larger or whether some people are 'hard-wired' to have more friends."

Social Networking

Facebook has more than 750 million users worldwide. The site allows people to keep in touch online with a network of friends, and the size of these networks varies considerably between individuals. While some people may only have a handful of friends, others have hundreds or thousands.

What has been unclear is whether there is any association between the number of friends a person has in cyberspace and the number of their real-life contacts.

There have been anecdotal suggestions that friends acquired through social networking are of a different character than those acquired through real-world social networks and that people may have more of one type of friend than the other.

Brain Scans

To investigate further, 125 students from UCL -- all active Facebook users -- underwent magnetic resonance imaging (MRI) brain scans. After scanning, the number of online and offline friends was recorded for each volunteer.

"Typically, the student population we studied had, on average, 300 friends on Facebook," says researcher Ryota Kanai, PhD.

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