Policy and Complex Systems
al intent are founded on an underlying set of beliefs . Individuals associate different outcomes with performing behaviors and weight those outcomes as either positive or negative in some way . Individuals also believe that people in their social network — their social referents — have expectations for the their behavior and the individual associates some motivation to comply ( or not comply ) with those referents ’ expected norms . Last , individuals hold beliefs about the presence or absence of factors that either facilitate or impede the performance of the behavior in question . Depending on how all of these beliefs come together , people formulate some level of behavioral intent that Ajzen contends is indicative of behavioral action ( see Figure 1 ).
Formally , TPB is constructed as follows . An individual ’ s behavior can be approximated by one ’ s behavioral intent BI , which is defined as the sum of one ’ s attitude ( AB ) toward the behavior , the one feels to perform the behavior , and one ’ s over the behavior .
Each of the three components are in turn functions of the individual ’ s underlying beliefs relative to the behavior in question . That is , individual j ’ s attitude toward behavior is given by the sum product
where is the strength of j ’ s belief in outcome and is j ’ s evaluation of outcome 0 . The overall attitude toward the behavior
is the sum of this product over all outcomes
associated with behavior . Simultaneously , individual j ’ s SN regarding behavior is given by
where is the individual j ’ s belief that referent r wishes j to perform behavior , and is individual ’ s motivation to comply with referent r . The overall subjective norm is the sum of this product over all the rele-
Figure 1 . Components of the TPB .
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