People throughout history have been intrigued by the question, “What is human nature?” Psychology’s approach to this topic is aimed at understanding basic patterns of thought, emotion, and behavior. It uses a variety of scientific methods, including interviews, case studies, field observations, neurophysiological recordings, and controlled experimentation. Psychology’s fund of knowledge has grown very rapidly over the past century. We now have a much clearer understanding of how people learn, how childhood experiences affect adult personality, how people influence one another during normal social relations, how to treat emotional and behavioral problems, how the brain’s biochemistry influences behavior, and many other significant topics.