Dr Carolyn McNabb is the Margaret Mead Award Lecture winner for Social Sciences. This Award is in recognition of their cutting-edge work and committed public engagement efforts. Full details of the 2020 Award Lecture winners can be found here: www.britishscienceassociation.org/news/introducing-our-2020-award-lecturers

The following interview with Carolyn has been written by Alan Barker, freelance writer

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How important is friendship and how can it change the way our brains behave? Drawing on her work using magnetic resonance imaging (MRI) to study the relationships between friendship, stress and the brain, Carolyn McNabb is exploring the ways social networking might help develop healthy adolescent brains. 

What were you looking for in this research? 

My research stemmed from a larger project conducted in the Motivation Science Lab at Reading University, which investigated whether motivation is contagious between schoolchildren. When we make friends, we tend to seek out people like ourselves – people with shared similar experiences and interests. It’s called homophily. But we might also become more similar to our friends just by spending time with them; that’s contagion. In the larger project, we asked whether homophily and contagion might extend to motivation: could what motivates one young person help to motivate their friends? And can we see this effect in the brain? An American research group recently showed that your brain, when it’s watching videos, is more similar to a friend’s brain than it is to the brains of other people further out in your social network.  

And that’s what you call neural homophily? 

Yes. We were also interested to know where the limitations of this pattern are; for instance, whether friends’ brains are also similar when they’re at “rest” – not engaged in some shared activity. Our brains are never really resting. Even when we’re thinking about nothing, the different regions of our brains communicate with one another. When you look at this activity over time (using MRI, for example), you start to see patterns: networks of areas communicating with each other. And these networks – we call them resting state networks – look similar in all brains. We were interested to know whether resting state networks are similar between friends. We measured the similarity in resting brain connectivity patterns across three different groups of schoolchildren, and we found no evidence for a relationship between friendship and resting brain similarity. Interestingly though, if you get these kids to do a motivational task in the MRI scanner, you start to see that neural homophily again. 

So there needs to be some social motivation for friends’ brains to behave in similar ways?

Well, we need to be careful. What we can say from these findings is that neural homophily does occur in the context of motivation, but doesn’t occur when brains are at rest. I’m sure other areas of behaviour would also exhibit neural homophily among friends if they were measured – we just haven’t measured them.  

Why are you interested specifically in young people? 

With young people – teenagers especially – lots of research has focused on the negative aspects of social influence: especially risk contagion. When teenagers are with their friends, they tend to take greater risks than when they’re by themselves. Our group is looking at other kinds of contagion: positive experiences like enjoying physical activity, or being keen on maths.  

So this research could help teenagers, with things like health outcomes… 

And educational outcomes. Maybe, if one pupil in a group of friends is enthusiastic about a subject, their enthusiasm might brush off on their friends. We know that being motivated to study something predicts higher educational performance just as well as intelligence – and sometimes better. So, we studied groups of teenagers two or three years running, asking them about their attitudes to motivation and mapping out their friendship networks – which can be quite volatile at this age. If we saw a particularly motivated student creating new friendships, and if we saw those new friends becoming more motivated, that would be evidence of contagion. We’ve seen that friendship can influence grit – a measure of determination – and also influence an interest in studying English. The next step would be to see if contagion extends to the way our brains function. 

How could MRI help you take that step? 

So far, we’ve looked at people’s brains just at one point in time. We’re planning to compare neural homophily over time – to see if we can find evidence of neural contagion.  

What’s the broader significance of this work? 

Teenagers are increasingly suffering from psychological problems. And we know that levels of friendship can predict levels of resilience. OIder people, for instance, can withstand adversity and bounce back after setbacks more effectively if they have strong friendship networks. We’re now planning to look at data from a huge MRI study called the Adolescent Brain Cognitive Development study – the ABCD study. It’s a long-term study of brain development and health in over 11,000 young people, including data about all sorts of things: parental history, sleep patterns, technology use, and most importantly, structural and functional brain data. We’re planning to interrogate the data in this study to find out whether having a large group of friends – or a small group of close friends – can protect the growing brain from the impacts of stressful life events.  

You make friendship sound really important. 

It is really important. I think sometimes we forget that play time is just as important for development as going to class and doing your homework. Friendship during adolescence can influence the developing brain in all sorts of ways – positive as well as negative. The more we learn about adolescent friendships – how friendship affects kids knowingly or subconsciously – the more we might be able to help them become great adults.

Alan Barker is a writer, trainer and coach specialising in communication skills. He has been working with the British Science Association since 2015. Alan’s webinar, Storytelling for Scientists, is on the 3M YouTube channel.