The evolutionary struggle for survival is really a self-serving series of blows and stabs, and yet it can lead to extremely social animals like dolphins, wolves or, for that matter, primates.

We start out postulating sharp boundaries, such as between humans and apes, or between apes and monkeys, but are in fact dealing with sand castles that lose much of their structure when the sea of knowledge washes over them. They turn into hills, leveled ever more, until we are back to where evolutionary theory always leads us: a gently sloping beach.

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.

The intuitive connection children feel with animals can be a tremendous source of joy. The unconditional love received from pets, and the lack of artifice in the relationship, contrast sharply with the much trickier dealings with members of their own species.

Darwin wasn't just provocative in saying that we descend from the apes - he didn't go far enough. We are apes in every way, from our long arms and tailless bodies to our habits and temperament.

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

We, who think like animals living in small groups, must structure a global world. We believe in universal human rights and believe racism and war are wrong. On the other hand, it is our nature to be cooperative and loving almost exclusively with the members of the group to which we feel we belong.