Why is organizational behavior a multidisciplinary subject?

Why is organizational behavior a multidisciplinary subject?
The purpose of organizational behavior is to gain a greater understanding of those factors that influence individual and group dynamics in an organizational setting so that individuals and the groups and organizations to which they belong may become more efficient and effective. The field also includes the analysis of organizational factors that may have an influence upon individual and group behavior. Much of organizational behavior research is ultimately aimed at providing human resource management professionals with the information and tools they need to select, train, and retain employees in a fashion that yields maximum benefit for the individual employee as well as for the organization.