The Nature of Things·Article

Why do we have friends? What makes dogs our best friends? Scientists decode the mysterious world of friendship

Judith Pyke set out to answer these questions and more in new documentary The Secrets of Friendship. Now streaming on CBC Gem.

Judith Pyke set out to answer these questions and more in new documentary The Secrets of Friendship

Two children sit across the table from each other, doing a puzzle-type activity. They are both wearing caps with wires coming out of them, which are used to monitor brain activity.
At the ToddlerLab in London, researchers are testing kids to see who will get most in sync when completing an activity together: siblings, friends or strangers? (Judith Pyke/Curious Features)

By Judith Pyke, director, The Secrets of Friendship

At some point in our lives, we all need someone to lean on. I've been there and I suspect you have too. I've also been the shoulder to cry on. But just as importantly, my friends and I turn to each other when good things happen or when we're just looking to have fun. My friends have been an essential part of my life. They've had an incredible influence on what I've done and who I've become. 

Remember back in the early days of COVID when we were cautioned against seeing our friends? I missed them — and that's when I started to think about friendship more and wondered what science had to say about it. 

The documentary The Secrets of Friendship is the result of our team's fascinating journey to find answers. We followed researchers observing dolphins and monkeys, peered into people's brains and personal lives, and filmed cutting-edge experiments while asking questions like: 

  • What exactly is a friend?

  • Do dogs think humans are nothing more than a meal ticket? 

  • Is there any connection between human and animal friendship? 

  • At what age does our social brain kick in? 

  • What can men do to create closer friendships?

In The Secrets of Friendship, you'll meet some amazing scientists as they investigate the social lives of humans and other animals in the hunt for clues and patterns to decode the mysterious world of friendship. 

Dolphins 'dance' together and macaques make friend requests

Travel to the turquoise waters off the coast of Australia where bottlenose dolphins whistle to stay in touch with their group, and "dance" a synchronized tango together in a display of the male-male bond. With global warming threatening their habitats, biologists Richard Connor, Stephanie King and Simon Allen are closely tracking the behaviour of these animals — documenting what they describe as the most complex social network outside of humans.

An underwater photo shows three dolphins clearly, and several more in the background.
Researchers have been studying dolphins in Shark Bay, Australia for decades. Male dolphins in Shark Bay, Australia have elaborate friendship networks and behaviours. (Kay Burn Lim/Curious Features)

On Cayo Santiago, a small island in Puerto Rico, rhesus macaques have a code for a friend request: a "lip smack." Lauren Brent, a scientist who studies animal behaviour, says usually when you see a female do it to another female, they will come closer together and might start grooming each other.

Brent is making fascinating discoveries about the power of friendship in rhesus macaques — for example, those with close and stable relationships, as well as a large number of weaker connections, have better biological outcomes. They live longer and have more babies throughout their lifetime. 

How (and when) humans make friends

Evolutionary psychologist Robin Dunbar believes that finding a shared activity can help us connect with our friends — and perhaps even make new ones. Laughing, singing and dancing together may all help strengthen bonds. 

"A friend is somebody fun to be with for you — you enjoy their company; you want to spend time with them," he says in the documentary. "But they're also the people that you would like and are willing to exchange favours with. You'd help them out if they needed help. They would help you out."

Supportive social relationships have been associated with a lower risk of health problems and increased longevity, so scientists are working on ways to understand our social development, and potentially help children develop social skills. Sarah Lloyd-Fox at the University of Cambridge's BabyLab is investigating how early our social brain 'kicks in.' At ToddlerLab in London, researchers test tykes with high-tech gear to unlock clues about empathy in children.

Who's most in sync: siblings, friends or strangers? | The Secrets of Friendship

2 months ago
Duration 2:52
At the ToddlerLab in London, England, a new study testing synchrony in young children is starting up. They monitor the brain activity and body movement of each pair of kids closely to see who will get most in sync: siblings, friends, or strangers? Watch The Secrets of Friendship on CBC Gem

At UCLA, social neuroscientist Carolyn Parkinson is investigating if brain scans can predict who will become friends. At the University of Winnipeg, psychologist Beverley Fehr has been studying friendship for decades. She's searching for the secret to creating strong male friendships. 

Are dogs really our best friends? 

Behavioural scientist Clive Wynne puts the bond between human and dog to the test to answer questions like can a canine companion really be our friend?; do dogs like humans more than food?; and would your dog rescue you if you were in trouble? 

I found myself deeply engaged with the work of the "friendship detectives" featured in this film. Even after working on the documentary for months, their discoveries and observations about friendship behaviour in humans and other animals still fascinate me. But of course it's interesting! Turns out we humans are innately social. 

Watch The Secrets of Friendship on CBC Gem.

Add some “good” to your morning and evening.

A variety of newsletters you'll love, delivered straight to you.

Sign up now