Evolution and morality

Objective morality may not exist, but morality does exist as a feature of human cultures and the human minds that underlie them. Scientists have documented reciprocity as a human universal that benefits everyone. Let's scratch each other's backs, but if you don't scratch mine after I've scratched yours, I'll notice and punish you for it. We humans aren't generally so good at solving logical puzzles, but if you find one that can be framed as a "cheating detection" problem, we're very good at it. Mutual aid helps us survive and reproduce, and refusing to aid others if they don't aid us keeps them from taking unfair advantage of us.

Humans are wired to identify with a group, belong to the group, and care passionately for its success independent of their own individual success. This started out as adaptive for the hunter-gatherer band, but has extended to larger units of organization as well. The ease and passion with which we modern humans can care deeply for the success of the local sports franchises shows how strong a tendency this is in us. It's not that people are willing to sacrifice all their personal interests for the group (think of the failure of collective agriculture most places it has been tried), but they will invest something in the group.

A popular position of moral philosophers is consequentialism or utilitarianism, whereby we should seek the greatest good for the greatest number. This would suggest that people in rich countries should give almost all of their resources to improving the lot of people in poor countries. But in fact, this very rarely happens. Humans tend not to share with people who are "other". Not many people give money to people far away. The nation-state is a very important unit of organization in today's world, and indeed Americans will often give to charities specific to America. But we're even more likely to give to our own community -- and most likely of all to save the bulk of what we have for our families. This suggests that morality as practiced by real people is more in line with evolution than abstract philosophical considerations.

Another prominent moral philosopher was Kant. His key insight was the categorical imperative, "Act only according to that maxim whereby you can, at the same time, will that it should become a universal law." I think one implication of that would be that in (say) 1980, when you could predict that the sum total of carbon emissions had a significant chance of making the earth a much worse place, each citizen of the earth would be obligated to reduce our carbon emissions to a level whereby we would have avoided this scenario. Obviously this didn't happen. It's hard to think of any cases where large numbers of people have followed this rule when it was counter to their own selfish interest. Once again, morality as actually practiced was shaped by evolution and is mostly impervious to philosophical argument.