This paper reviews the literature on human attitudes to animals, and postulates the existence of two primary motivational determinants of attitudes labelled ‘affect’ and ‘utility’. It also proposes that the relative strengths of these key attitude dimensions are affected by various modifying variables including the specific attributes of the animal, the individual characteristics and experience of the person evaluating the animal, and a range of cultural factors. The role of science as a cultural modifier of human attitudes to animals is also discussed.