Mind & Body

How many friends can your brain handle?


How many is too many when it comes to friendships? Well, apparently there’s a magic number and neuropsychologist Dr Hannah Korrel reveals all here.

Ever felt pressure to be perfect? To be living your best life, surrounded by smiling friends, and ‘winning’?

The growth of technology means we are more socially connected and more exposed than ever, so the pressure to appear perfect and popular is also higher than ever. It also means we’re more likely to compare ourselves to others.

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Social misconceptions about friends

Society has this thing called ‘norms’ but not all of them are correct – ‘a woman’s place is the kitchen’, ‘big men don’t cry’, ‘people should just ‘snap out’ of depression’. Some, like these, are now being challenged and slowly broken down by society.

Friendships also have norms, for example, ‘once a friend, always a friend’, ‘cool people have lots of friends’, and ‘it’s better to give than to receive’. Norms like these can cause us to keep friends in our lives who are less than nice to us, to value quantity over quality, and give-give-give while expecting nothing in return. But new research is showing us what’s actually ‘normal’ for friendship…

Dunbar’s number: The science of friendship

Think of the size of your brain compared to, say, a squirrel. You can do a lot more stuff than a squirrel because your bigger brain has more cognitive real estate.

Prominent researchers investigating relationships are showing that the size of our neocortex may actually correspond to how many close relationships you can handle at any one time.

They theorise the closer, and more complex, the relationship, the fewer people you can handle on that level.

The number of very close relationships that our brains can handle is theorised to be… drum roll… a very reasonable, five.

This is called the Dunbar number and it includes family members, too. Your mum, dad, your child, a sibling and maybe one or two close friends are the people you interact with pretty much daily, or at least weekly. This makes sense because there are literally only so many hours in the day to interact with other people, so our ‘relationship real estate’ is limited.

The next level of friends expands to about 15. These are less close, but still considerably close relationships, which includes the friends and family we see one to two times a month.

Then you can have about 50 people in your ‘active network’ – the less close friends you have ‘drinks’ with every three months.

And the maximum capacity you brain can handle is 150 acquaintances. These are the people you’d place in the ‘I’d recognise at a house party’ category.

People can move up and down these relationship levels as time goes by and as we go through different life stages. So while at university, all five of your ‘really close’ positions maybe have been university friends.

When you hit marriage, parenthood and career growth, these closer slots maybe switched to family or business partners.

We may float in and out of each other’s lives depending on how similar or different our life stages are (they may be down for the daiquiris but not at the diaper stage – and that’s OK!).

What does this mean for friendship?

It’s perfectly normal to have a few friends and for the number of ‘really close friends’ to fluctuate overtime as life naturally ebbs and flows. Some months it may feel like 20 super close buds, other months it might be two. The key is to not be too hard on yourself if you’ve been busy with uni, work and building a new family because they probably have been, too!

The important take home message is that you pay attention to the quality of friends you share your precious time and energy with, not the quantity.

Epidemiological research tells us that strain friendships are associated with greater chronic illness, negative health effects on par with obesity and smoking, and shorter life spans.

Conversely, good quality friendship is associated with longer life, better health, happiness, more success and even staving off dementia. This research showed it wasn’t the number of friends that causes this affect; it was all about the quality, so even ONE good friend can have this positive effect.

Don’t get sucked into believing the ‘norms’ that you must have hundreds of friends to be happy – and certainly don’t keep toxic people around just for the sake of having ‘more friends’. Save your valuable brain real estate for the penthouse, baby.

Neuropsychologist Hannah Korrel is the author of How to Break Up With Friends (Impact Press, $24.99) and has spent over a decade becoming an expert in why the brain makes us do the things we do. Visit her website or follow her on Instagram @nobullpsych.