Presented here are three research studies examining psychological characteristics underlying attitudes toward the use of nonhuman animals: beliefs and value systems; their comparative impact on opinions; and empathetic responses to humans and to animals. The first study demonstrated that the attitudes of laypeople are context dependent: different sets of beliefs underlie attitudes toward various types of animal use. Belief in the existence of alternatives (“perceptions of choice”) was especially important, accounting alone for 40% of the variance in attitudes. The second study compared the opinions, beliefs, value systems, and empathetic responses of scientists, animal welfarists, and laypeople. Results demonstrated that laypersons are most similar to the science community, not the animal welfare community. Scientists and laypeople differed on very few measures, whereas animal welfarists differed on most measures. The third study demonstrated a causal link between belief and attitude: manipulating “perceptions of choice” led to a significant change in support for animal use. These studies explain how individuals and groups can have dramatically different attitudes toward animal use and demonstrate how opinions can be changed.