I've argued that many of what philosophers call moral sentiments can be seen in other species. In chimpanzees, gorillas, orangutans and humans, you s… - Frans de Waal

To endow animals with human emotions has long been a scientific taboo. But if we do not, we risk missing something fundamental, about both animals and us.

It is true that the chimpanzee is dominance-oriented, violent, territorial. But it's also cooperative in many ways, and so that side is sometimes forgotten. The bonobo is sensual, sensitive, sexual, a peacemaker, but also can have a nasty side, and that's sometimes forgotten. So both species are sort of the ends of the spectrum, and we fall somewhere in between. Clearly, we have both of these sides in us, and that's why I sometimes call us "the bipolar apes."

In 1879, American economist Francis Walker tried to explain why members of his profession were in such "bad odor amongst real people". He blamed it on their inability to understand why human behavior fails to comply with economic theory. We do not always act the way economists think we should, mainly because we're both less selfish and less rational than economists think we are. Economists are being indoctrinated into a cardboard version of human nature, which they hold true to such a degree that their own behavior has begun to resemble it. Psychological tests have shown that economics majors are more egoistic than the average college student. Exposure in class after class to the capitalist self-interest model apparently kills off whatever prosocial tendencies these students have to begin with. They give up trusting others, and conversely others give up trusting them. Hence the bad odor.