Based on the results of several experimental studies, the article substantiates the serious influence of the presence of dogs and cats on the characteristics of the state and course of human activity, in particular, during testing. It is shown that in a stressful situation, the presence of a cat has a positive effect on the psychological and physiological state of the subjects, especially men. The article also presents the results of a study of people’s subjective ideas about the role and functions of dogs and cats in the modern family. It has been found that the psychological roles and functions of dogs and cats subjectively perceived by people in modern culture are very diverse, and only a small part of these roles can be considered as related to a potentially formal status (“pet”), for the most part these roles are informal and reflect a variety of socialpsychological relationships.