Male chimpanzees have an extraordinarily strong drive for dominance. They're constantly jockeying for position.

Male bonobos really don't fit the human male ideal.

I have often noticed how primate groups in their entirety enter a similar mood. All of a sudden, all of them are playful, hopping around. Or all of them are grumpy. Or all of them are sleepy and settle down. In such cases, the mood contagion serves the function of synchronizing activities.

When someone brutally kills someone else, we call him "animalistic." But we consider ourselves "human" when we give to the poor.

Studies of reconciliation in primates have demonstrated that if the relationship value increases between two parties they are more willing to make peace.

If we look straight and deep into a chimpanzee's eyes, an intelligent self-assured personality looks back at us. If they are animals, what must we be?

Male chimpanzees have an extraordinarily strong drive for dominance. They're constantly jockeying for position.