People have free will, that is, subjective judgments, personal preferences, and choices. From the perspective of psychological research, the harder you succeed, the happier you are; the more success you need to think about, the happier you are. ; The more satisfied you are through self-control, the happier you are. The tracing experiments of psychologists have found that the more able to endure their impulsive children, the easier it is to get into college, get married, and get a doctorate. Children who cannot help meeting their desires immediately are more likely to drop out of school, more likely to divorce, and more likely to be frustrated. The text is intended to explain:. ["People's efforts to succeed are directly proportional to their happiness.", 'The degree of control over free will determines how happy people are.', 'Happiness as a subjective experience can be explored with psychological methods.', "Cultivating a child's self-control ability from an early age is essential for his growth."]