Theory of Planned Behavior
summary of TPB relationships
-TPB has better predictive power than TRA -attitude, PBC, and subjective norm are better predictor of intention than behavior -relationships with intention: -attitude (large) -perceived behavioral control (large) -subjective norm (weaker relationship than attitude or PBC)
main difference between TRA and TPB
-TRA does not have control beliefs/PBC
constructs
-attitudes -subjective norms
belief based structures
-behavioral beliefs -normative beliefs -control beliefs
perceived behavioral control
-degree of personal control the individual believes they have over the behavior -informed by control beliefs (expectancy x value) -expectancy: presence of absence of barriers/facilitators -value: ability of barriers and facilitators to impact behavior -influences behavior directly and indirectly (through intentions)
development of TRA/TPB
-long history of poor results using attitudes to predict behavior -FIshbein and Ajzen (TRA:1975; 1980) (TPB: 1985; 1988) -assess attitudes toward specific behavior -added idea of intention preceding behavior -commonly used by 1980s -another value-expectancy theory -expectancy: beliefs about PA -value: relative importance of those beliefs
formation of attitudes
-teen/early adult years -influence by important others -resistant to change
intention
-most proximal determinant of behavior -person's willingness and how much effort they are willing to exert to perform the behavior -function of attitudes, social norms, and PBC (in TPB) -intention and time? -intention and behavior?
assumptions of TRA/TPB
-people weigh consequences and implications of their actions and then decide whether to act -pros vs cons -rational decisions? -intention must be highly correlated with behavior
subjective norms
-perceived social pressure that individuals feel to perform or not perform a particular behavior -informed by normative beliefs (expectancy x value) -expectancy: perceived expectations of important significant others or groups -value: individual's motivation to comply with the expectations of important others
attitudes
-positive or negative evaluation of performing a behavior -informed by behavioral beliefs (expectancy x value) -expectancy: perceived consequences of carrying out a specific action -value: personal evaluation of each of these consequences
attitudes towards PA
-positive: good, beneficial, enjoyable, advantageous -negative: bad, not enjoyable, time consuming, painful
TPB strength and weaknesses
-strengths: -good predictor of short term intention/behavior -frequently used to understand physical activity behavior -used in a wide variety of contexts -weaknesses: -limited by time between intention and behavior -not designed as a theory of behavior change
