Here's why:

* Sociology is the study of human society, its structures, functions, and interactions. Sociologists examine how individuals behave within groups, how groups interact with each other, and the social forces that influence these interactions.

* Other fields like anthropology might also study human groups, but their focus is often on cultural practices and the evolution of human societies.

* Psychology focuses on individual behavior and mental processes, while social psychology investigates how individuals are influenced by groups and social contexts.

While other disciplines may touch upon the behavior of human groups, sociology is the primary field dedicated to its study.