I'm the author of the Psychology of the Masses: Why You Believe What You Believe and Do What You Do. My book is about how and why people are so groupish. We get our ideas and habits mainly from the people we know. We fall easily under the spell of what has authority or prestige. The book explores the relationships between crowd psychology and a number of other fields, and develops a general theory of human nature. The subject matter can be and has been effectively applied to practical purposes.