alt Hacker News> unique among animals in that we have a genocidal tendency
That's an unsupported generalization.
The article describes "behaviors" that include "perhaps even genocide", and notes that wiping out populations exists in chimps and wolves too.
So not unique, there's a "perhaps", and it's not a tendency. There's no evidence we have a "gene" for it or anything.
In the vast, vast, vast majority of conflicts between two groups, we don't exterminate the "enemy". Otherwise, the human race would have gone extinct a long time ago. Wiping out entire populations is by far the exception, not the rule, of human societies. It happens, but the situations are notable precisely for their extremity, precisely because they're not the norm.
We are far more subtle and targeted about it as a whole, possibly due to our social structures.
As vapid as the movie (intentionally) is, "Mean Girls" does a really good break-down of things, and perhaps the main issue is that unlike some other animal groups, people don't always stop.