But perhaps more startling, and disturbing, was the tendency for aggression and violence within chimpanzee troops. Goodall observed dominant females deliberately killing the young of other females in the troop in order to maintain their dominance, sometimes going so far as cannibalism. She says of this revelation, “During the first ten years of the study I had believed […] that the Gombe chimpanzees were, for the most part, rather nicer than human beings. […] Then suddenly we found that chimpanzees could be brutal—that they, like us, had a darker side to their nature.” These findings revolutionized contemporary knowledge of chimpanzee diet and feeding behaviors, and were further evidence of the social similarities between humans and chimpanzees, albeit in a much darker manner.