Vested interest (Crano, 1983; Crano & Prislin, 1995; Sivacek & Crano, 1982) is a communication theory that seeks to explain how an attitude of self-interest can affect behavior; or, in more technical terms, to question how certain hedonically relevant (Miller & Averbeck, 2013) attitudinal dimensions can influence and consistently predict behavior based on the degree of subjective investment an individual has in a particular attitude object.
As defined by William Crano, vested interest refers to the degree to which an attitude object an idea, concept, or value with potential emotional interest is deemed hedonically relevant by the attitude holder. According to Crano, "an attitude object that has important perceived personal consequences for the individual will be perceived as highly vested. Highly vested attitudes will be functionally related to behavior" (Crano, 1983). Simply put, when people are more emotionally or psychologically invested in the results of an object (like a law or policy that may greatly affect them), they will behave in a way that directly supports or defies the object to protect their own self-interest.
For example, a 30-year-old learns that the legal driving age in his state is being raised from 16 to 17. While he may not agree with this proposed change, he is not affected as much as a 15-year-old would be and is unlikely to protest the change. A 15-year-old, however, has much more to lose (waiting another year to get a driver license) and is more likely to strongly oppose the proposed law. To gather support for his position, the 15-year-old might tell other soon-to-be drivers about the new law, so that they collectively have a vested interest in perhaps changing the law. This example illustrates how highly vested attitudes concerning issues depend on the individual's point of view.
Another example of vested interest can be found in a study conducted by Berndsen, Spears and van der Pligt, which involves students from a University in Amsterdam where the teaching faculty proposed the use of English to teach the curriculum instead of Dutch. Vested interest, in this case, suggests that students would be opposed to the use of English rather than Dutch simply based on the potential impact lectures conducted in English might have on their grades. Organizations who strive for collaborative success benefit from understanding vested interest and that of other collaborators in order to maintain a supportive level of involvement. In a study conducted by John Sivacek and William D. Crano, they prove the aforementioned statement that ego involvement and vested interest are indeed separate. Sivacek and Crano state, Essential to social judgment theory is the idea of ego thus actions or ideas with a varying degree of ego involvement carry a commensurate amount of vested interest to the individual as detailed by Sherif, Kelly, Rogers, Sarup, and Tittler. Sherif, et al. in 1967 who stated that individuals with little to no options have corresponding vested interest indicating low ego involvement. who defined this concept by stating that “central, ego-involved, and salient attitudes” often include attitudes significantly important to individual interests. In politics, for example, voters have a vested interest in candidates whose values (policy) align with their own to include attitudes toward these values. Due to the nature of politics, voters come to conclusions about one candidate over another based on perceived attitude importance (object) on these policies rather than vocal support alone placing a high value on this concept as it pertains to vested interest. Initially, outcome relevant objects retain a high degree of vested interest while not appearing to be. Secondly, outcome relevant involvement suggest interest ends once the goal is achieved whereas vested interest suggests a self-perpetuated interest. The following sections explain each of these variables in greater detail.
Stake
Stake refers to the perceived personal consequence of an attitude that is directly related to the intensity of vested interest and influences components that contribute to attitude-behavior consistency. In its basic form, the more that is at stake concerning a particular issue, the stronger the attitude will be. Consequently, as attitude strength increases, the consistency of attitude-based actions also increases. In a situation where stake is operationalized using certainly and immediacy, one found the likely effect of this was behavior relative to the immediate consequence, positive or negative. Mortality, for instance, would become salient when faced with a situation where death was probable or the known death of a friend, relative or an experienced event which resulting in someone's death. This death salience would then influence behavior for a short amount of time following the event.
Certainty
Certainty refers to perceived likelihood of personal consequences as a result of an attitude or action. Certainty must be a concept which is pushed onto us much like truth is a certainty beyond our immediate control. This is seen in a mechanism which allows people to agree to donate organs in the event of their death (i.e. drivers licenses). An example of this would be physical fitness, in that, elevated or decreased self-efficacy will cause one to accept or deny a strenuous task daily. created high and low vested interest groups by identifying whether upper- or lower-classmen would pay a surcharge to subsidize lost funding from the government. The class who was selected to pay the surcharge had a high degree of vested interest while the student body not required to pay exhibited a lower degree of vested interest. The study then determined the participants estimate of what percentage of the student body would support their beliefs regardless of impact. Crano found that vested interest influenced assumed consensus and students believed that a majority of the university's population would support their plight even though only half would be affected. conducted this study utilizing 81 male and female students at the University of Yale. In this experiment the objective was for half of the participants to show their own attitude toward smoking policies and the other half to show their thoughts on others attitudes toward smoking policies. The group with the questionnaire regarding their personal attitude about smoking were asked: 1. if they were a smoker or a nonsmoker, 2. how heavy or light a smoker they were, 3. whether they would support an increase on cigarette tax, 4. would they do away with smoking advertisements, and 5. their thoughts on smoking restrictions in public places. The second half of the participants were asked what percentage they thought smokers would support the previously mentioned policies for smokers or nonsmokers. They were not asked whether or not they smoked. The results of this study replicated Green and Gerkin's 1989 study that nonsmokers had more support for smoking restrictions than did those that smoke. If people tend to overestimate the number of others who share their beliefs, this tendency should be exacerbated in situations involving personally consequential, or highly vested, beliefs. Research supports this expectation.