Recent studies have shown that chimpanzees engage in apparently altruistic behaviour within groups,^[21][22] but are indifferent to the welfare of unrelated group members.^[23]

Evidence for "chimpanzee spirituality" includes display of mourning, "incipient romantic love", "rain dance", appreciation of natural beauty such as a sunset over a lake, curiosity and respect towards wildlife (such as the python, which is neither a threat nor a food source to chimpanzees), empathy toward other species (such as feeding turtles) and even "animism" or "pretend play" in chimps cradling and grooming rocks or sticks.^[24] However, whether or not these behaviors are best explained with reference to spirituality is still debated.^{[citation needed]}