Economists assume that people act on their self interest. So why do we sometimes see people act altruistically? It might have something to do with helping others who share your genes, like family members. This helps your character traits make it to the next generation. That also assumes that what genes want to do is replicate and spread themselves. Here is an excerpt from the article:
"Altruism has always been a bit of a problem. Every altruist has their own motives, of course—some are emotional, responding to fellow humans in desperate straits, while others are more rational, thinking about the kind of society they’d like to live in and acting accordingly. Does that imply a level of self-interest? Even if it did, it shouldn’t undo the goodness of altruism, and yet people can be deeply suspicious of those who apparently willingly put others’ interests before their own. Selfless acts often attract accusations of hidden selfishness, suggesting they’re not really altruistic at all.
This wasn’t the problem for Darwinism. After all, humans have culture and religion and moral codes to live by—maybe our altruism was more to do with that than biology. Unfortunately, altruism was not only a human trait—it was everywhere. There were birds that nurtured other pairs’ fledglings, vampire bats that regurgitated blood for those who’d failed to feed in the night, monkeys that put themselves in danger by raising the alarm when a predator approached the rest of their troop.
It was altruistic ants that posed a particular problem for Charles Darwin. Natural selection is often described as “survival of the fittest,” where fitness means how successful an individual is at reproducing. If one individual has a trait that gives them a fitness advantage, they will tend to have more offspring than the others; because the advantage is likely to be passed on to their offspring, that trait will then spread through the population. A fundamental part of this idea is that individuals are competing for the resources they need to reproduce, and fitness includes anything that helps an individual reproduce more than the competition.
But as Darwin observed, ants and other social insects are not in competition. They are cooperative, to the extent that worker ants are sterile and so have literally zero fitness. They ought to be extinct, yet there they are in every generation sacrificing their own reproductive ambitions to serve the fertile queen and her drones. Darwin suggested that competition between groups of ants—queen, drones, and workers together—might be driving natural selection in this case. What was good for a nest competing against other nests would then outweigh what was good for any individual ant.
Group selection, as this idea was known, was not a very good solution, though. It didn’t explain how the cooperative behavior evolved in the first place. The first altruistic ant would have been at such a huge disadvantage compared to the rest of its group that it would never have got the chance to breed more altruistic ants. The same was true of humans—natural selection was intrinsically stacked against any altruistic individual surviving long enough to pass on their altruism.
This left a rather embarrassing paradox: The evolution of altruism was impossible, yet clearly altruism had evolved. If the biologists couldn’t resolve this, would they have to throw out the whole idea of natural selection?
Luckily, a young man called Bill Hamilton spared biology’s blushes with a slightly different solution in 1964. He proposed that altruism could have evolved within family groups—yes, an individual altruist would seem to be at a disadvantage, but that was not the whole picture because other individuals who shared the same genes associated with altruism would all influence each other’s “inclusive fitness.”
Discussions of human altruism are often framed in terms of someone drowning in a pond. Do you put your own life at risk to try and save them? If you do, that’s altruism. Hamilton’s idea, which became known as kin selection, acknowledged that compared to a selfish person who never got their feet wet, someone who went around jumping into ponds to save drowning people would be at a greater risk of dying before they managed to reproduce and pass their altruistic genes on to their children. However, if they happened to save a relative who shared the same genes, our altruist would have indirectly helped to get those genes passed on to the next generation after all. If the total benefit derived from having altruistic genes in the family, so to speak, was greater than the cost, then the evolution of altruism was no longer paradoxical."