Thomas D. Parsons Ph.D.

This Is Your Brain on Technology

Does Online Social Networking Change Your Brain?

New research relates the size of brain regions to online social network size.

Posted May 11, 2018

Gerd Altmann/Pixabay
Source: Gerd Altmann/Pixabay

How many friends do you have on Facebook? The answer is probably more than the number of friends you have offline in your everyday life. Social neuroscientists have found that our brains facilitate, make use of, and are partially affected by a broad array of social interactions. In fact, research has found a relationship between the size of our brain regions and the number of friends we have offline. Does the enhanced ability to connect via online social networks amplify the changes in our brains?

Source: WikiImages/Pixabay

According to the social brain hypothesis, the size of the primate neocortex (as compared to the whole brain) is related to multiple aspects of our social activities (e.g., social learning, coalitions, mating strategies, deceptions, and social network size). The social brain hypothesis aims to explain the expansion of the human brain throughout the course of evolution. Within this framework, humans who worked collaboratively had a survival advantage. Social neuroscientists contend that our brains may have evolved to interact with one another in ways that allow us to work collectively and thrive in our everyday environments.

Recent studies support relations between human social group size and the size of the brain areas involved in social cognition. Oxford University’s Robin Dunbar has proposed that the number of friends we can have in our social network is limited to the size of our brain areas implicated in social cognitive processes. According to Dunbar, humans typically have a limit of 150 stable relations. It should be noted that this number excludes people we just generally know and includes friends with whom we have social contact. Dunbar hypothesizes that our neocortical processing capacity limits the number of people we can have in our social network.

While Dunbar’s number is an interesting hypothesis for understanding our offline social networks, it was developed prior to the advent of online social networks like Facebook. An obvious question is whether the enhanced opportunities for connecting to others and our regular use of social media have changed the relevance of Dunbar’s number. It may be the fact that online social networks allow us to maintain more “stable” relations. If that is the case, does it mean that there will be an even stronger correlation between the size of our brain areas and associated online social networks (e.g., Facebook, Twitter, Instagram)?

Studies have found relations between a person’s involvement in online social networks and the anatomical structure of brain regions that are believed to be involved in social cognition. For example, Kania and colleagues (2012) looked at the relations between a person’s sociability (e.g., number of Facebook friends and the results of a social network size questionnaire) and the brain’s amygdala volume, as well as the volume of several cortical brain regions. These brain regions (left middle temporal gyrus, right superior temporal sulcus, right entorhinal cortex) were ones that had been identified previously for their associations with theory of mind. They found that a person’s number of online social connections was strongly related to the structure of these focal brain regions. Specifically, the variation in the number of Facebook friends significantly predicted grey-matter volume in the left middle temporal gyrus, right superior temporal sulcus, and right entorhinal cortex. Moreover, they found that the grey-matter density of the amygdala (shown previously to be linked with offline social network size) was also significantly related to online social network size.

In another study, Von der Heide and colleagues (2014) examined both the number of Facebook friends and two real-world measures (Dunbar’s number and Norbeck Social Support Group). They found that brain volume differences predict social network size across a range of measures. Moreover, their findings proffer support for left and right amygdala involvement, as well as the orbital frontal cortex and entorhinal/ventromedial anterior temporal lobe.

Wikimedia Commons
Source: Wikimedia Commons

Support for Dunbar’s number in online social networks has been found in studies that ask the participants to report information about their online networks. For example, Nicole Ellison and colleagues (2011) at the Michigan State University asked undergraduates about their Facebook use and found that although their median number of Facebook friends was 300, the number of those they actually considered friends was around 75. Dunbar (2016) also surveyed social media users and found that the number of Facebook friends who are actual friends is similar to that of offline face-to-face networks. For Dunbar, this suggests that the neurocognitive limits on the number of friends is the same for both offline or online social networks.

A challenge to these results is that the studies asked people to report the number of friends they thought they had. Often, social connections are not necessarily reciprocal. Someone may report that you are a friend, but you may consider that person to be more of an acquaintance. New findings are emerging from studies that compare information beyond individual self-reports of friendships to regional brain volume. Kwak and colleagues (2018) looked at the social networks of an entire village and found that social ties identified by a person’s actual social connections (rather than those reported by the person) significantly correlated with larger social brain regions. Interestingly, the person’s self-reported (i.e., self-perceived) connections showed no associations. These results suggest that future studies may want to look more at global social networks, instead of just a person’s self-report.

The answer to the question of whether online social networks amplify the changes in our brains is "maybe." It is important to remember that correlation does not equal causation. We do not know whether the correlation found between brain structure and online social networking arises over time through friendship-dependent brain plasticity. We also do not know whether persons with particular brain structures are predisposed to have more online friends. That said, the emerging work in cyberpsychology and the brain does show promise for extending our knowledge of the connection between our brains and social media.