Are humanism and the principle of reciprocity (the Golden Rule) compatible with evolution? This is a topic had I planned on covering in this series but I got busy and forgot until the good doctor, JW reminded me. So let’s consider how these piece together.

If you look at our closest extant relatives, bonobos and chimpanzees, then we will see that they are very much social creatures. They live in rather large groups with a social hierarchy and, to a limited extent, division of labor with hunting parties going out while some stay behind to care for the band’s young. They have found that their survival is improved by communal cooperation.

The driving force in natural selection is whether or not something increases the likelihood of surviving to pass on ones genes. This kind of social structure they have developed has increased the likelihood of procuring food, increased the likelihood of driving away predators, and improved the availability of mating partners.

So how does this relate to humans? Let’s assess the Golden Rule’s implication on survival. Let’s imagine two men in a nomadic band, we’ll call them Gog and Mog. If on the first hunt Gog succeeds in killing the deer, then Mog would hope that he would share with him. On the next hunt, if Mog killed the deer then he likely want to share with Gog.

If instead Gog and Mog constantly yelled and bickered, withheld resources from each other, and in no way helped each other out, they would likely reach the point of trying to kill each other or parting ways.

So say they part ways and each take half the band with them, due to the smaller size of the group there are fewer mouths to feed, but also a smaller group to find food and hunt animals. If all they had were clubs to kill their prey, then each group’s hunting success rate would lower at a faster rate than the decreased demand for resources. As such, they would more likely to starve.

Of course there is more to evolution than just survival, we have to pass on our genes for it to matter. What woman in this nomadic band would want to mate with a jack ass like we’re describing. This guy would be almost as likely to deny her and their children resources as he is everybody else. Also if he’s only looking out for himself then what would keep him from just leaving her to raise their children alone if times got tough.

Instead imagine that Gog and Mog go out and hunt and each time they catch something they share equally. They treat each other with respect and do to each other what they would want done to themselves. They would be more likely to have food to eat, thus more likely to survive. The women in the nomadic band would also see this and feel more sure that to mate with one of them would mean security for herself and her offspring.

As it turns out, the Golden Rule carries with it a high selective advantage, thus it is compatible with evolutionary theory.