chimpanzee

At that moment there was no need of any scientific knowledge to understand his communication of reassurance. The soft pressure of his fingers spoke to me not through my intellect but through a more primitive emotional channel: the barrier of untold centuries which has grown up during the separate evolution of man and chimpanzee was, for those few seconds, broken down.It was a reward far beyond my greatest hopes.

But let us not forget that human love and compassion are equally deeply rooted in our primate heritage, and in this sphere too our sensibilities are of a higher order of magnitude than those of chimpanzees.

You can't teach calculus to a chimpanzee. So just share your banana.