There's actually a lot of evidence in primates and other animals that they return favors.

Science is not inherently good.

Chimpanzees, typically, kiss and embrace after fights. They first make eye contact from a distance to see the mood of the others. Then they approach and kiss and embrace.

I am personally not against keeping animals at zoos, as they serve a huge educational purpose, but treating them well and with respect seems the least we could do, and with 'we' I mean not just zoo staff, but most certainly also the public.

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

Empathy as a complex emotion is different. It requires awareness of the other person's feelings and of one's own reactions. The appropriate reaction may not be to cry when another person cries, but to reassure them, or even to leave them alone.

The primate laugh is given in playful contexts, and as such has a strong similarity to the human laugh.