Ankur Desai

Things were going swimmingly.

quite well for them, and that's one of the things that makes this study hard for me to understand and come to grips with.

They were actually benefiting in so many ways by living in this large group, but they probably reached a breaking point where, in a sense, they became victims of their own success.

The group grew so large that they couldn't hold together anymore.

Feeding competition intensified, reproductive competition among the males intensified, and a few males died just before hostilities broke out in 2015.

And as a result of that, there could have been changes in social dynamics elsewhere.

leading to hostilities that weren't there before.

There was a change in the alpha male right around the same time.

That often leads to increased levels of aggression.

There was this combination of factors that came together that led to the split.

And can we learn anything about our own human capacity for violence or conflicts from times when it seems that it's peaceful and then suddenly things erupt?

Can we learn anything at all?

I've studied chimpanzees now for a very long time, and if there's one thing I've come to learn is not how similar they are to us, but that they're different.

We've known for a very long time that chimpanzees will kill and attack their neighbors.

The surprising finding reported in this paper is that they will do so even when those neighbors are former friends and allies.

So chimpanzees appear to consider outsiders as the enemy, no matter who they are.

We typically don't act in this way.

One stark difference that exists between chimps and humans is that we're an unusually pro-social and cooperative species.

We go out of our way to help and aid neighbors, some of whom may be total strangers.

And this ability to get along with others is unusual, if not unique.