Here's another question for you: Why do most humans avoid killing, stealing, telling lies, and breaking promises? In other words: why are most of us moral agents? There are basically three competing hypotheses. All three assume that morality is ultimately a brain activity.
The "Good-Natured Hypothesis" (GNH) argues that beginning in the Pleistocene era, (3 million years ago) biological evolution (natural selection and sexual selection) endowed us with a "natural" set of mental mechanisms that facilitate living in small, cooperative groups. Some of these mechanisms are "rational" (located in the outer layers of the brain) some are "emotional" (located in the outer layers of the brain). Despite these mechanisms, it's also obviously true that, today, some of us modern humans still act like Chimpanzees, that is: kill, steal, lie, and break promises? (The question of whether Chimpanzees are good-natured or bad-natured is open to debate.) In fact, some human groups are literally "infected" with immoral behavior: organized crime syndicates, some inner-city neighborhoods, and the Afghan military and police forces. How do these infestations of immorality take root and how can we "cure" them? Based on the GNH, there is a "mismatch" between slow-paced biological evolution (genes) and fast-paced cultural evolution (ideas). If we want to "restore" natural communal cooperation, we need to cure those cultural viruses (bad ideas) so our good nature can shine through again.
On the other hand, the "Bad-Natured Hypothesis," argues that biological evolution has endowed us with a set of mental mechanisms that promote self-interest, predation, and "dog-eat-dog" competition. Cooperation, they argue requires a degree of altruism, which is naturally limited to within families and kin groups. These "selfish genes" tend to impede the formation of cooperative groups, so if we want to improve communal cooperation, we must overcome our bad nature via cultural evolution (good ideas). Our "bad nature" is most clearly evident in the universal persistence of human warfare, murder, theft, lying etc. Despite our best cultural efforts, major parts of the world remain locked in intractable warfare (think: Israelis v. Palestinians, drug lords v. drug lords, democrats v. republicans). Based on the BNH, morality is unnatural, in the sense that it is the product of cultural evolution, or ideas. In other words, at some point in human history, human beings "discovered" that we can overcome these selfish genes via teaching and learning. Imagine the revelation: "Hey you all, listen up...if we really work at it, we can resist our natural impulse to kill, steal, lie, and break promises. Then we can reap the benefits of living in large cooperative communities. Just think: We can free ourselves from incessant hunting and gathering and buy our food at Kroger. No more warfare either! In short, despite our bad nature, we really can 'get along!' "According to the BNH, when we revert back to our "bad nature" all we have to do is develop cultural institutions that can keep them in check, things like: educational institutions, criminal justice systems, political parties etc.
So the "Good-Natured Hypothesis" says that morality is primarily the product of biological evolution, and the "Bad-Natured Hypothesis says that morality is fundamentally the product of cultural evolution. The third hypothesis, which I call the "Good and Bad Natured Hypothesis," GBNH is a hybrid of both, with many variations. Here are two variations.
GBNH Variation #1 argues that human beings have two sets of genetically programmed brain mechanisms. One set constitutes our good nature (genes for: intelligence, reciprocity, feelings of sympathy, etc.); the other our bad nature (genes for: stupidity, predation, lying, cheating, stealing, etc.). Although the good nature mechanisms for cooperation within families tend to be more powerful than the mechanisms cooperation between strangers, both are at least possible. But there's really not much we can do about it, other than discover how those brain mechanisms work and perhaps re-program them via genetic therapy, drug therapy, or maybe brain surgery. Hence, "You scratch my back and I'll scratch yours" can only be enhanced by increasing serotonin and reducing testosterone levels within specific populations either via eugenic programs, drug therapy, or by brain surgery (most likely targeting the limbic system).
GBNH Variation#2 argues that although we have both "good" and "bad" brain mechanisms, we can increase the manifestation of good mechanisms by deliberately altering the environment in which we live. For example, we could move out of those large cities into smaller kin groups of about 150, make sure there enough healthy food to go around (but not too much!), and keep cooperative human males engaged in good groups (such as: schools, churches, sports teams, police and fire departments) and away from bad groups (such as: gangs, organized crime, the military, and the banking industry).
Now here's that initial question again! Are human beings "good natured" or "bad-natured?" Are those "natures" the product of biological evolution, cultural evolution, or both? What, if anything, can we do individually or collectively to maximize our "good nature" (if there is one) and minimize our "bad nature" (if there is one)? As soon as I figure it all out, I'll post in on this blog. It could take a while...