Psychology includes basic psychology and applied psychology, and its research involves many fields such as perception, cognition, emotion, thinking, personality, behavior habits, interpersonal relationship, social relationship, etc., as well as many fields of daily life-family, education, health, society, etc. On the one hand, psychology tries to explain the basic behavior and psychological function of individuals with brain operation, and at the same time, psychology also tries to explain the role of individual psychological function in social behavior and social motivation; In addition, it is also related to neuroscience, medicine, philosophy, biology, religion and other disciplines, because the physiological or psychological effects discussed by these disciplines will affect the individual's mind. In fact, many humanities and natural disciplines are related to psychology, and human psychological activities are inseparable from human living environment.

Psychologists engage in basic research to describe, explain, predict and influence behavior. Applied psychologists also have a fifth purpose-to improve the quality of human life. These goals form the basis of psychology.

Psychological research involves many fields such as perception, cognition, emotion, personality, behavior, interpersonal relationship and social relationship, as well as many fields of daily life-family, education, health and so on. On the one hand, psychology tries to explain the basic behavior and psychological function of individuals with brain operation, and at the same time, psychology also tries to explain the role of individual psychological function in social behavior and social motivation; At the same time, it is also related to neuroscience, medicine, biology and other sciences, because the physiological functions discussed in these sciences will affect the mind of individuals.

Psychology not only helps to make a descriptive explanation of psychological phenomena and behaviors, but also points out the law of the emergence, development and change of psychological activities. People's psychological characteristics are quite stable, but they also have certain plasticity. Therefore, we can predict and adjust the behavior of ourselves and others within a certain range, and we can also adjust our behavior by changing internal and external factors. In other words, we can try our best to eliminate unfavorable factors, create favorable situations and trigger positive behaviors of ourselves and others. For example, when we find that we have some bad psychological qualities and habits, we can use the law of psychological activities to find out the internal and external factors that induce these behaviors, actively create conditions to change the influence of these factors, and realize the transformation of our own behaviors. For another example, rewards and punishments play an important role in cultivating children's good habits and transforming children's bad behavior habits by using the principle of conditioned reflex.