8 billion people: how different the world would look if Neanderthals had prevailed

[Random Boomer]

5. Unfriendly is such a vague term

A good case can be made for Neanderthals/Denisovans being more aggressive than Homo sapiens, based on the traits that are characteristic of domesticated species. Humans appear to be a self-domesticated species, and one of the facial traits associated with domesticated species in a shorter nose/snout and slighter frame. (There are others, but I don't have time to go look them up right now.) This would certainly be mirrored in the differences between humans and Neanderthals.

Less aggression between individuals leads to greater cooperation and teamwork in all aspects of survival, from food gathering to hunting. This is a powerful competitive edge over other species living in many of the same overlapping ecological niches.

For more on this topic, I recommend The Goodness Paradox: The Strange Relationship Between Virtue and Violence in Human Evolution by Richard Wrangham.