In Proceedings of the Royal Society B: Biological Sciences, British and Danish researchers stress that the relationship between the amount of Facebook friends and human brain structure is a correlation-not a causal relationship. In other words, it has not been shown that by adding more Facebook friend, your brain will grow in size.
“Our findings support the idea that most people use Facebook to support, maintain or strengthen their existing social relationship. This in stead of using these networks to create a whole new set of virtual friends”, says reasearcher Geraint Rees of University College London (UCL).
The researchers studied brain scans of 125 students, who were all active Facebook users. They also examined how many online and real world friends the participants had. As a result, the researchers found a strong correlation between the number of friends on Facebook and the amount of gray matter in certain brain areas. One of these areas was the amygdala, where emotional responses are processed. A previous study published in Nature Neuroscience shows that people with a lot of “real” friends have a greater amount of gray matter in the amygdala area.
Researcher Ryota Kanai from UCL concludes: “We know that the brain is plastic and can change over time. The exciting question now is whether this also applies to brain areas such as the amygdala. This helps us in determining whether the Internet is changing our brains.”
R. Kanai1, 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
Bickart KC, Wright CI, Dautoff RJ, Dickerson BC, & Barrett LF (2011). Amygdala volume and social network size in humans. Nature neuroscience, 14 (2), 163-4 PMID: 21186358