Transactional analysis is a theory that analyzes human behavior and communication. It was developed by Eric Berne and uses a model of ego states to explain how and why people think, act, and interact. The three ego states are the parent, adult, and child. The parent ego state is programmed by childhood experiences and role models. The adult ego state processes information objectively. The child ego state involves emotions learned from childhood. Effective communication involves complementary exchanges between people's adult ego states, while crossed or ulterior transactions are less direct.