Future benefits rarely figure in the minds of animals.

The thinking is that we started evolving language not by speaking but by gesturing.

As far as the environment is concerned, I am becoming pessimistic because I do not see anybody stepping up and taking the long view approach. It seems like we're stuck in a tragedy of the commons where everyone is trying to contribute as little as possible to get out of this situation.

People want to work with somebody who feels shame, who worries about the perceptions of others. Dishonesty is something we don't like in others.

A chimpanzee who is really gearing up for a fight doesn't waste time with gestures but just goes ahead and attacks.

I sometimes try to imagine what would have happened if we’d known the bonobo first and the chimpanzee only later—or not at all. The discussion about human evolution might not revolve as much around violence, warfare and male dominance, but rather around sexuality, empathy, caring and cooperation. What a different intellectual landscape we would occupy!

In humans, the family prevents infanticide. Next to language, the core family, consisting of a mother, a father and children, is the greatest difference between us and other primates.