Transactional analysis (TA) is a theory of communication that views interactions between people in terms of ego states and transactions. TA was developed in the 1960s to understand behavior. It analyzes exchanges between two or more individuals (transactions) and examines personality structure (ego states). The ego consists of three parts - parent, adult, and child - that influence transactions. TA is used to understand behaviors, improve communication, and address dysfunctional relationship patterns like "games." While popular in therapy, TA lacks scientific evidence proving some of its key concepts.