Positive psychology is the scientific study of human strengths and optimal functioning. It has three aspects: positive emotions, positive individual traits, and positive institutions. Positive emotions include happiness and hope, individual traits include strengths like love, courage, and wisdom, and positive institutions refer to strengths that foster better communities. Positive psychology differs from positive thinking in that it is grounded in scientific study and recognizes that negative thinking can sometimes be appropriate. Wealth is weakly related to happiness, while activities like "flow" that people engage in for their own sake can lead to fulfillment. Positive psychology aims to build on individual strengths and informs people about how their choices impact well-being without being prescriptive.