Dogs likely were the first animals to be domesticated and as such have shared a common environment with humans for over ten thousand years. Only recently, however, has this species' behavior been subject to scientific scrutiny. Most of this work has been inspired by research in human cognitive psychology and suggests that in many ways dogs are more human-like than any other species, including nonhuman primates. Behavior analysts should add their expertise to the study of dog behavior, both to add objective behavioral analyses of experimental data and to effectively integrate this new knowledge into applied work with dogs.