Are humans getting better? | New Europe ;.. We might think that evolution leads to the selection of individuals who think only of their own interests, and those of their kin, because genes for such traits would be more likely to spread. But, as I argued then, the development of reason could take us in a different direction.
On the one hand, having a capacity to reason confers an obvious evolutionary advantage, because it makes it possible to solve problems and to plan to avoid dangers, thereby increasing the prospects of survival. Yet, on the other hand, reason is more than a neutral problem-solving tool. It is more like an escalator: once we get on it, we are liable to be taken to places that we never expected to reach. In particular, reason enables us to see that others, previously outside the bounds of our moral view, are like us in relevant respects. Excluding them from the sphere of beings to whom we owe moral consideration can then seem arbitrary, or just plain wrong.