The theory of transactions, along with ego states, lies at the core of understanding Transactional Analysis. In fact both ideas are intrinsically related.
All interactions between people can be broken down into a series of transactions, comprised of a stimulus and a response. For example as I left my home this morning I saw my neighbour hanging out washing. I smiled and shouted “hello” (the stimulus) and she smiled and waved in return (the response). As you can see transactions are not just verbal, they include body language, gestures and tone of voice.
Each transaction can be seen as coming from a specific pair of ego states. It is important to understand that different stimuli can invite different responses from others. In this way understanding and changing our own behaviours can change the nature of our interactions with others.
Transactions theory has clear applications in all 4 fields for building powerful relationships.
Example of Adult-Adult parallel transaction
Example of Parent-Child parallel transaction
Example of crossed transaction