Robin Dunbar

It exploits a lot of the same machinery, if you like, so causal reasoning and stuff.

But the key to that seems to be that it involves what's become known as mentalising.

It's the capacity to understand what's going on in somebody else's mind, essentially, or at least to be able to predict how they're going to behave in the future and to manage and manipulate that to some extent.

And that is...

extremely expensive in terms of neural processing time.

And that's why you end up having to have this huge bit of the brain essentially dedicated to...

managing social relationships.

A bit of a sniff to figure out... And that's the difference between herding species, like feral goats, who don't have stable relationships and don't have stable groups, because there's no point in learning...

the ins and outs and foibles of a particular individual, because you may never see them again.

All you need to know is, are they a bigger thug than you?

Are they prettier than you?

Have they got a nice red nose?

Or whatever the cues are.

If you're in a stable group, you've got to do much more machinating, really, in order to keep everybody in the same place.

Because the problem is, as I'm sure you all know, if you're too grumpy...

with your friends when you go out, they'll abandon you.

So if you start being too aggressive within the group, you destroy the group.

It's the skills of diplomacy.

And the ones that have stable groups, stable monogamous groups as a pair, invariably have bigger brains than the ones that have a pair mating arrangement but don't live together.

I mean, the answer is yes, if you look at it.