 Though in its strictly literal sense, “anthropomorphism” simply makes reference to the attribution of human-like characteristics to animals, in its common usage in comparative cognition it has a very negative connotation, such that it is used to make reference to the mistaken attribution of human-like characteristics to animals. Thus understood, anthropomorphism is connected to humans’ well-documented tendency to over-attribute mental states. This was already demonstrated in the 1940s, in a famous study by Fritz Heider and Marianne Simmel (1944). In this study, human participants were shown a video that depicted animated geometric shapes moving around the screen (see Heider and Simmel (1944) animation in  Other Internet Resources  for the video). Although the shapes make no sounds and have no facial expressions, the participants couldn’t help but interpret their movement in intentional terms and construct a narrative regarding their “interactions”. This is a particularly egregious example of our anthropomorphic biases, which lead us to be inclined to interpret the behavior of entities (human, non-human, and beyond) in human-like terms. Scientists studying animal cognition are well aware of this problematic tendency, and they attempt to counter it by stressing the importance of avoiding anthropomorphism.