An increasing body of research work has made it clear that, while Felis catus can survive in the solitary state, social groups with an internal structure, are formed whenever there are sufficient food resources to support them. Most people who have cats have two or more cats. Failure to understand what will promote either friendly or aggressive behavior can lead to various behavior problems, including aggression and conflict over resources, such as food, resting sites and litterboxes. An understanding of the natural social organization, relationships and communication between cats is therefore essential, and is the subject of this paper.

Familiarity and relatedness are significantly associated with allogrooming and proximity of another cat. This may be important when considering adoption of 1 or more kittens and when adding a new cat to a household in which other cats are present. Adopting small family groups may result in higher rates of affiliative behavior, stronger bonding, and lower incidence of conflict than periodically adopting single unrelated adult cats.

Factors influencing dominant-subordinate relationships are of interest for understanding and treating behavior problems such as aggression and resource control. The outcome of agonistic interactions away from food was related to, but not perfectly correlated with, the outcome of interactions at the food bowl, although winners of those agonistic interactions tended to have control of food.