The Social Network

Over the past years, we have learned more and more about the brain than we ever thought we could. Every so often, a new brain area becomes attached to a particular aspect of human functioning. One of the latest findings revolves around friendship. Is there a friendship area of the brain? What do the brains of people with high quality friendships look like? Researchers were curious to study how brain development across childhood and adolescence may be linked to individual differences in social capabilities.

We all know how crucial friendships are for our mental health. All the more at a young age, when we are developing our capacities to integrate socially into the “real world”. With the rapidly growing imaging technology and understanding of the structural brain, we gain the opportunity to answer questions once clouded in mystery.

The “social brain” consists of the medial prefrontal cortex [mPFC] (an area near the front of your brain), temporal parietal junction [TPJ] (near the back), and the posterior superior temporal sulcus [pSTS] (near the bottom). The study was based on using MRI (magnetic resonance imaging), a popular brain imaging technique that uses magnetic fields to generate structural images.

First, the researchers aimed to highlight the structural development of the brain, and then focused on analyzing whether differences in development were related to friendship quality. These goals were consistent with the recent trend in literature of defining neurological changes to predict indicators of mental health. Understanding who may be prone to experiencing low friendship quality allows for preventative measures and support to reduce future mental health risk.

The analyses showed that the mPFC and TPJ parts of the social brain were shown to be linked to friendship quality across adolescence. Higher decreases in mPFC dimensions over time were linked to this higher quality friendship trait. This may appear counterintuitive. Why? Cortical thinning (the decrease in surface area) is actually an indicator of the brain making its processes more efficient and integrated. Think of it as the brain fine tuning itself.

As for the TPJ, lower baseline dimensions were correlated with higher quality friendships later on in adolescence. In contrast to the previous finding with the mPFC, the researchers concluded that this lower baseline meant increased opportunity for growth over time and thus potential for high quality friendships. So whether it be through shrinking or growing, the brain certainly finds intriguing ways to develop!

These findings tie in nicely with what we know about these two brain areas - both have an established role in social cognition, contributing to: empathizing, understanding social cues, and prosocial behaviours.

From this study, it’s clear that specific parts of the social brain are more heavily involved in determining how friendships play out. By mapping out these areas, we are once again reminded of the importance of brain health, and the need to pursue healthy environments, diets, and lifestyles to sustain it in order to maintain our ability to thrive in all aspects of life.

Understanding these subtle nuances are incredibly important for not only our growing knowledge of the brain, but also to identify individuals who may benefit from early intervention. This study serves the narrative we’ve been seeing lately in healthcare, of shifting from reactive to preventative practice.

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Source:

• Becht, A. I., Wierenga, L. M., Mills, K. L., Meuwese, R., van Duijvenvoorde, A., Blakemore, S. J., ... & Crone, E. A. (2021). Beyond the average brain: individual differences in social brain development are associated with friendship quality. Social cognitive and affective neuroscience, 16(3), 292-301. https://academic.oup.com/scan/article/16/3/292/6024637