At the time, scientific models of human and animal behavior virtually never overlapped.[9] Some scientists accused her of excessive anthropomorphism;[9] others suggested that her presence, and her practice of feeding the chimpanzees, had created violent conflict in a naturally peaceful society.[10] However, later research using less intrusive methods confirmed that chimpanzee societies, in their natural state, wage war.[10][11] A 2018 study published in the American Journal of Physical Anthropology concluded that the Gombe War was most likely a consequence of a power struggle between three high-ranking males, which was exacerbated by an unusual scarcity of fertile females.[12]