When the sample size gets small enough, there are obviously opportunities for gleaning non-statistical information by using carefully crafted querys to read between the lines. I remember somebody telling me that they worked pretty hard to make sure this couldn't happen. Now I think it fairly easy to see that the capacity to put group survival ahead of self-interest is an important genetic trait and that tribes of people that had this trait would be more likely to survive that tribes that didn't. That is not to say that this moral capacity doesn't vary greatly from one person to the next or that even that it may not be more fully realized in one person than another because of upbringing. It is even possible that, because of some genetic error, some people may be born without a moral capacity, just like they might be born without arms or legs.
Moral progress means the evolution of survival customs more appropriate to the current context.
The trouble in recent centuries has been that our ability to evolve new technology has outstripped our capacity to evolve the appropriate morality for it. Evolution is being used with its Darwinian meaning but with an interpretation that includes the more ordinary progress of mankind. Until disaster strikes the adapted and unadapted survive undifferentiated.