Are we born with moral values or we acquire it over time?

Someone claims that to think raping a little child is right is like accepting 2+2=5 is right... so from this he proves that moral values are things that we're born with rather than acquired over time, with that, we understand why an animal mourns over the death of its child, why animals defend one another against predators, even risking their lives at times... animals surely haven't acquired these moral values, therefore, we're born with these moral values just like animals are... this is my view about it, what about yours?