William Glasser developed Choice Theory and Reality Therapy. Choice Theory explains that human behavior is determined by an individual's choice to meet their basic psychological needs for survival, love, power, freedom and fun. According to Glasser, behavior is purposeful and consists of acting, thinking, feeling and physiology. Students will engage more in school if it allows them to meet their basic needs through interesting activities. Choice Theory includes the concepts of an individual's Quality World of wants and needs, their Perceived World of experiences, comparing the two, and engaging in total behavior to reduce any mismatch.