John Steiner is a person who studies how people think and feel. He helps them understand why they act the way they do. Imagine if you have a big puzzle in front of you, and you have to figure out how all the pieces fit together. John Steiner does something similar, but with people's thoughts and feelings. He asks them lots of questions and listens to what they say. He wants to help them understand what makes them happy, sad, and scared. It's like he's solving a puzzle in their minds!