Temperament in Domestic Cats: A Review of Proximate Mechanisms, Methods of Assessment, Its Effects on Human—Cat Relationships, and One Welfare

SIMPLE SUMMARY: Temperament can be understood as an animal’s individuality or character. In addition, the terms ‘personality’ and ‘individual differences’ has also been reported. This article presents a literature review of more than three decades of research on temperament in domestic cats, emphasizing its origins and development, methods of assessment, and how the structure of temperament in cats was deciphered. The effects of temperament on human–animal relationships and welfare are also included. Advances in cat temperament research are presented and discussed, identifying possible gaps in knowledge, as well as opportunities for future research. ABSTRACT: Temperament can be defined as interindividual differences in behavior that are stable over time and in different contexts. The terms ‘personality’, ‘coping styles’, and ‘behavioral syndromes’ have also been used to describe these interindividual differences. In this review, the main aspects of cat temperament research are summarized and discussed, based on 43 original research papers published between 1986 and 2020. We aimed to present current advances in cat temperament research and identify potential gaps in knowledge, as well as opportunities for future research. Proximate mechanisms, such as genetic bases of temperament, ontogenesis and developmental factors, physiological mechanisms, and relationships with morphology, were reviewed. Methods traditionally used to assess the temperament of cats might be classified based on the duration of procedures (short- vs. long-term measures) and the nature of data recordings (coding vs. rating methods). The structure of cat temperament is frequently described using a set of behavioral dimensions, primarily based on interindividual variations in cats’ responses toward humans and conspecifics (e.g., friendliness, sociability, boldness, and aggressiveness). Finally, cats’ temperaments have implications for human–animal interactions and the one welfare concept. Temperament assessment can also contribute to practical aspects, for example, the adoption of shelter cats.