Hoping this doesn't come off as an aggressive creationist "If evolution is true, then why am I such a good person?" post. I'm an agnostic atheist. I believe that morality is like science or math--already there, waiting to be discovered through trial, error, and hard thinking. I want to know if there's some evolutionary evidence which explains why people usually have consciences. Is it because not murdering fellow members of your race tends to improve your species' ability to continue existing? Or social self-preservation, since consciences are largely rooted in cultural values? What circumstances might have made having a conscience beneficial for survival? Are other intelligent Earth species known to have consciences? Is there a scientific, rather than philosophical, way to address the question of whether intelligent life on other planets would have similar morality to our own?

 

Is it because not murdering fellow members of your race tends to improve your species' ability to continue existing?

 

I think that is part of it. But also, just being able to trust others, which means you must be (at least partly) trustworthy yourself. Evolution has probably worked like game theory to reach a Nash Equlibrium.

 

At one extreme we have psychopaths who have no conscience at all. There is a genetic basis for that, which suggests that not only has morality/conscience evolved but perhaps that psychopathy can sometimes be useful and so it hasn't been eliminated completely...

At one extreme we have psychopaths who have no conscience at all. There is a genetic basis for that, which suggests that not only has morality/conscience evolved but perhaps that psychopathy can sometimes be useful and so it hasn't been eliminated completely...

 

I can be genetic without being inherited (mutation), or it can be recessive, with some positive trait conferring an advantage with one copy (as with sickle cell & malaria, Cystic Fibrosis & cholera, or Tay-Sachs & tuberculosis) rather than the recessive trait being the advantage.

Well, recent studies suggest that empathy has developed at least in social mammals quite early on. One assumption is that this is necessary to form any social structure (i.e. to be able to identify yourself to some degree with someone else). As in many species social behaviour has a number of advantages, it can be assumed that elements such as neuronal elements involved in evoking empathy are under positive selection in many cases.

The development of morality is, potentially an abstraction of these biological foundations.