The differences you perceive between Humans-between groups of Humans-are the result of isolation and inbreeding, mutation, and adaptation to different Earth environments
Octavia Butler...I realized that I knew less about loneliness than I had thought - and much less than I would know when he went away.
Octavia ButlerWe need the stars... We need purpose! We need the image the Destiny to take root among the stars gives us of ourselves as a purposeful, growing species. We need to become the adult species that the Destiny can help us become! If we're to be anything other than smooth dinosaurs who evolve, specialize and die, we need the stars.... When we have no difficult, long-term purpose to strive toward, we fight each other. We destroy ourselves. We have these chaotic, apocalyptic periods of murderous craziness.
Octavia ButlerYou are hierarchical. That's the older and more entrenched characteristic. We saw it in your closest animal relatives and in your most distant ones. It's a terrestrial characteristic. When human intelligence served it instead of guiding it, when human intelligence did not even acknowledge it as a problem, but took pride in it or did not notice it at all... That was like ignoring cancer.
Octavia Butler