Development of the behavioral repertoires of animals is often affected by interaction with conspecifics. Consequently, innovative behaviors can spread through a population and result in stable differences in the behavioral repertoires of geographically separate populations of a species. Although traditions in animals and culture in humans serve similar functions, they often result from quite different underlying behavioral processes. Humans speak, teach, and imitate. Although there is considerable evidence that apes sometimes imitate, even our closest phylogenetic relatives do not teach using signals as we do. Propagation of traditions in animal groups results not only from signals evolved to communicate, but from social learners acquiring information by observing the life-sustaining activities of others.