The Theory of Reasoned Action is a psychological model that explains how individual behavior is influenced by their intentions. It posits that a person's intention to perform a behavior is determined by their attitude toward the behavior and the subjective norms surrounding it. In other words, if someone believes a behavior is positive and perceives that important people approve of it, they are more likely to engage in that behavior. This theory was developed by social psychologists Martin Fishbein and Icek Ajzen in the 1970s. It is often used in fields like health promotion and marketing to predict how people will act based on their beliefs and social influences. Understanding these factors can help in designing effective interventions to change behaviors.