A long time ago, our evolutionary system made an important choice. It chose to grow our brains. This is how we came to be the dominant species on the planet.
There was a trade-off, though. Having bigger brains meant we also had bigger heads – and bigger heads pose a significant reproductive problem for a species with narrow hip-bones.
The only way to get round this problem was to shortcut the reproductive process, by having our babies delivered before they were equipped to fend for themselves (unlike the baby giraffes and gazelles you see in wildlife programmes, who can run from the moment they’re born).
That’s why human beings are instinctively social animals – because, from our first breath, we depend on the group to look after us.
By the time we reach 18 months old (which might be a more appropriate gestation period), we’re equipped to survive on our own. But we don’t. Most of us continue to live as part of a group for the rest of our lives.
It’s a pattern you only find repeated in our closest animal cousins: apes and chimpanzees. They also form into groups for protection, with very clear hierarchies. There are the alpha males, those who are permitted to groom the alpha males and those who groom the groomers and each other. The grooming is an essential part of establishing each member’s place and their commitment to the group.
Human beings operate in the same way. The difference is that our bigger brains have allowed us to evolve more sophisticated forms of grooming than our simian cousins. Instead of picking nits out of each other’s fur, we establish our place and our commitment to the group through our ability to communicate.
And because language is a more time-efficient form of grooming than nit-picking, it means our social groups can be much larger than the average group of chimpanzees.
They can also be more varied. Most of us operate as part of different groups – family, friends, work, community, club – which can change in make-up and location as our lives evolve. These groups inform the way we think and the choices they make. We do what people like us do.
When there’s a discrepancy between the norms of the different groups we belong to – friends and work, for instance – that can make life confusing and unsettling for us. It makes it hard to decide what we ought to think and what we ought to do.
Which is why organisations that make it simpler – by allowing people to act and think in the same way they would with their friends or family – are the ones that tend to succeed.
You can give people all the rational reasons in the world why they should do something.
But the truth is that they’re much more likely to be swayed by what their friends think.