That kind of "human nature" that comes as a conclusion from the fact of what's hardcoded in a newborn baby is only a trivial kind, and not generally what people mean when they talk about "human nature" any more than the fact that babies are born with different eye colours tells us about human nature. Human nature, by definition, is found common to all humans, so a difference in "skills and aptitudes" does not say anything with regards to human nature (or the essence or appearance of it) other than "humans have skills, aptitudes and personality traits hardcoded" (which seems like a very strong claim to me anyway), but that itself would only be a trivial statement. It wouldn't tell us whether it's human nature (in the transhistorical, transsocietal sense) to be cooperative or greedy, violent or peaceful, etc.

Even so, understanding the fact that there is a human nature does not bring us much closer to what that human nature entails. Anthropologists, historians, economists, philosophers, and (some) evolutionary psychologists have a lot to say on the topic. To say that something is "just human nature" requires more evidence than "human nature is unchanging, applicable to all, and transhistorical".