Evolutionary psychology is one of four sciences that are bringing human nature back into the picture.

But the 20th century suffered "two" ideologies that led to genocides. The other one, Marxism, had no use for race, didn't believe in genes and denied that human nature was a meaningful concept. Clearly, it's not an emphasis on genes or evolution that is dangerous. It's the desire to remake humanity by coercive means (eugenics or social engineering) and the belief that humanity advances through a struggle in which superior groups (race or classes) triumph over inferior ones.

For one thing, before the 20th century, there were plenty of genocides. We tend to forget about them, partly because they weren't as well documented and partly because, until recently, people didn't care. We used euphemisms like 'sackings' and 'sieges' instead of calling them 'genocides.'

The European wars of religion were more deadly than the First World War, proportionally speaking, and in the range of the Second World War in Europe. The Inquisition, the persecution of heretics and infidels and witches, they racked up pretty high death tolls.

Something about the topic of consciousness makes people, like the White Queen in Through The Looking Glass, believe six impossible things before breakfast.

... people notice differences and expect every difference in form to convey some difference in meaning.

With violence, as with so many other concerns, human nature is the problem, but human nature is also the solution.