Which factor does the theory of planned behavior consider as influencing an individual's intention?

The theory of planned behavior posits that an individual's intention to engage in a behavior is influenced by three primary factors: attitudes towards the behavior, subjective norms, and perceived behavioral control.

Attitudes refer to the individual's positive or negative evaluations of the behavior in question. If a person believes that a behavior will lead to positive outcomes, they are more likely to intend to engage in that behavior. Subjective norms involve the perceived social pressure to perform or refrain from a behavior, which can be shaped by the beliefs about what significant others think. Finally, perceived behavioral control reflects the individual's perception of their ability to perform the behavior; greater perceived control often leads to stronger intentions.

In contrast, while environmental constraints can influence actual behavior, they are not part of the internal mechanisms that the theory focuses on for intention formation. Genetic predispositions and physical attractiveness are not directly addressed in this theory, as it primarily centers on cognitive and normative influences rather than biological or superficial traits. Thus, the combination of attitudes, subjective norms, and perceived control forms the foundation of the theory and collectively contributes to an individual's behavior intentions.