Moral behavior is a survival adaptation. 50,000 years ago there were several human species roaming the world. Homo Sapiens were but one of those species, but they survived due to the most remarkable of their adaptations; a highly socialized brain. Whereas Neanderthal man's brain was just as big but ideal for the visual acuity necessary to be a good hunter, Homo Sapiens' brain was ideal for making social connections with other Homo Sapiens. In other words, humans are HARDWIRED FROM BIRTH TO WORK TOGETHER AND HELP EACH OTHER OUT. Being altruistic toward one another is precisely why Homo Sapiens are still alive today, whereas all those other human species like Neanderthal man have gone extinct.
The person who adapts to the world gets more done because they have learned how to navigate society and culture. Unreasonable people usually spend a lot of time banging their heads against walls instead of walking through doors.
