This article discusses the Theory of Planned Behaviour (TPB) in social psychology and its application in understanding individual behavior and attitudes. It explores the factors that influence behavior change and the role of attitudes, subjective norms, and perceived behavioral control. The TPB is applied to various areas such as health behaviors, social problems, and behavioral problems in different age groups. The article also discusses the effectiveness of the TPB in predicting intentions and behavior and its practical utility in changing attitudes.