Are we smart enough to remember how smart animals are?

Some theoretical perspectives suggest people overestimate animals’ mental capacities (anthropomorphism), while others suggest they underestimate them (mind-denial). However, studies have generally not employed objective criteria against which the accuracy or appropriateness of people’s judgements about animals can be tested. We employed memory paradigms, in which judgments are clearly right or wrong, in 9 experiments (8 pre-registered; n = 3162). When tested shortly after exposure, meat-eaters’ memory about companion-animals (e.g., dogs) but not food-animals (e.g., pigs) showed an anthropomorphic bias: more information consistent with animals having vs. lacking a mind was correctly remembered (Experiments 1-4). Vegetarians and vegans memory, on the other hand, consistently showed an anthropomorphic bias regarding food and companion animals alike (Experiments 5 and 6). When tested a week after exposure, both those who eat meat and those who do not showed signs of shifting toward a mind-denying bias (Experiments 2, 3, and 6). These biases had important consequences for beliefs about animal minds. Inducing mind-denying memory biases caused participants to see animals as possessing less sophisticated minds (Experiments 7-9). The work demonstrates that judgments about animals’ minds can depart predictably from reality and that such departures can contribute to biased perceptions of their minds.