Anthropomorphism, anthropectomy, and the null hypothesis

We examine the claim that the methodology of psychology leads to a bias in animal cognition research against attributing “anthropomorphic” properties to animals (Sober in Thinking with animals: new perspectives on anthropomorphism. Columbia University Press, New York, pp 85–99, ; de Waal in Philos Top 27:225–280, ). This charge is examined in light of a debate on the role of folk psychology between primatologists who emphasize similarities between humans and other apes, and those who emphasize differences. We argue that while in practice there is sometimes bias, either in the formulation of the null hypothesis or in the preference of Type-II errors over Type-I errors, the bias is not the result of proper use of the Neyman and Pearson hypothesis testing method. Psychologists’ preference for false negatives over false positives cannot justify a preference for avoiding anthropomorphic errors over anthropectic (Gk. anthropos—human; —to cut out) errors.