Thread by @Brahamvakya

Brain is formed by life experiences & since an individual doesn't keep doing what doesn't work (learns through trial and error), evolution has reinforced the behavior, values that help us survive and reproduce. This behavior must be the behavior that was adaptive in environment

in which humans spent most of their evolutionary history. The qn then becomes: What was the operating environment in which human brain evolved?
Human evolution started about 5-7 mln yrs ago & today's "modern" human brain appeared on the scene some 150,000 to 200,000 Yrs ago

For most of that time our ancestors lived in primitive hunter-gatherer societies as agriculture evolved some 12-15000 years ago. meaning over 99% of human evolution journey has been as hunter-gatherer & what made our fore bearers survive and evolve?

What enemies, predators, and dangers existed? What behavior has been natural during 99% of our history? Since natural selection is about survival and reproduction, and individuals either survive or die and reproduce or not, it makes sense that individuals are predisposed to act

in ways that enhance their own prospects for survival and reproduction.Altruistic individuals are at a disadvantage. They are always vulnerable to some mutants that take advantage of them. Altruistic behavior cannot evolve by natural selection since

natural selection favors individuals that are best at promoting their own survival and reproductive success. If that has been the empirical history then why are Hindus jumping over each other's heads to be altruistic,benevolent.. sacrificing self for others? Think, learn, adapt

Only behavior that is selfish or for the mutual good is in an individual's self-interest and therefore favored by natural selection.