 Philosophical assumptions in animal cognition research are present, most obviously, in how the capacities under study are defined. For instance, when scientists embark on an experimental project to determine whether a certain species has capacities such as altruism, cooperation, or empathy, they assume a certain definition of these terms. These definitions are often operational, meaning that they focus on the behavioral or physiological reactions that one would have to see in an animal to confirm that they possess this capacity. But even operational definitions come with philosophical baggage. For instance, some scientists consider that finding emotional contagion in an animal is enough to claim that that species is capable of empathy. This presupposes that a particular philosophical account of empathy is true, and not others. Some phenomenological accounts of empathy, for instance, do not require emotional state-matching (Zahavi &amp; Overgaard 2012), and so, under these accounts, finding emotional contagion in an animal would not suffice to claim that they are capable of empathy.