Dale Carnegie (born November 24, 1888) was an American writer and teacher renowned for his courses in self-improvement, salesmanship, corporate training, public speaking, and interpersonal skills. He is the author of the enduring bestseller "How to Win Friends and Influence People" (1936) and "How to Stop Worrying and Start Living" (1948), among other books. A core idea in his work is the ability to change others' behavior by altering one's own behavior towards them.