In 2005, UCLA researchers announced that chimpanzees were “indifferent to the welfare of unrelated group members.” These scientists grouped 18 chimps into pairs of two and presented one from each pair with two options. One action resulted in a presumably tasty snack for both, and the other choice resulted in the same snack for only one chimp—the one making the choice between the two actions. The researchers found that the chimpanzees more often chose to reward themselves, and did not consider the needs of their partner where the situations did not involve the risk of harm from indifference. Sort of like when you pretend not to see someone running to catch the elevator, just because.
Yet, in a new study conducted by the Yerkes National Primate Research Center, scientists found that the average chimp would hold the elevator for you. The 2011 Yerkes study, let by scientist Frans de Waal, refutes the UCLA results and methods as introducing bias and competition between the chimps—thus giving a subtle advantage to choosing selfishness over altruistic behavior.
In de Waal’s study, he and co-authors J. Devin Carter, Victoria Horner and Malini Suchak, presented a group of all-female chimpanzees (eliminating gender-based competitive behavior,) with a container of 30 tokens. In each experiment, de Waal’s group offered two colors of tokens, one of which rewarded only the active participant and the other that resulted in an additional snack for a chimp nearby.
De Waal felt that the UCLA study missed critical factors and that his team, “…explicitly ensured that both [chimps] and partners could see how choices were made and how these choices affected them.” De Waal’s study follows observations of spontaneous altruistic actions in chimpanzee species, including “remembering and returning favors.” De Waal’s study also dispelled the theory that chimpanzees only acted altruistic in response to social pressure—the chimps selecting between token colors did not change their behavior in response to pleading or whining from their partner. The choosy chimps were just as likely to select for a mutual reward whether their partner attempted to influence their choice or not.
From donkeys to dogs, empathy and altruistic behavior isn’t rare in the animal kingdom, and studies like those of the UCLA only show an absence of altruism in specific circumstances (i.e. “hold the elevator.”) This is not equivalent to proving that altruistic behavior never happens in a group of animals—the 2005 study may have only proved that “Heathers” has more in common with “Planet of the Apes” than one may have thought.
For more information on the work of the Emory University Yerkes National Primate Research Center, visit their website at www.yerkes.emory.edu.