"Think Again" is a book by Adam Grant, an organizational psychologist and a professor at Wharton. The book is about the ability to rethink and unlearn. Grant argues that in a rapidly changing world, it is crucial to regularly question one's beliefs. He suggests that people tend to adopt the style of a preacher, prosecutor, or politician when making decisions and engaging with others, which hinders their ability to reassess their views. Grant proposes that thinking like a scientist, which involves questioning assumptions, conducting experiments, and adjusting strategies based on outcomes, can lead to more informed decisions and less biased thinking.