Cognitive responses to positively and negatively framed health messages: a thought-listing study.

This study compared spontaneous cognitive responses to a positively vs. negatively framed health message. Deakin University students (n = 51) read one of two versions of a message concerning a type of heart disease. In the negative condition, the message focused on the prospect of experiencing heart disease; in the positive condition, it focused on the prospect of avoiding heart disease. Participants completed a thought-listing task, reporting any thought that occurred to them while they were reading the message. Consistent with hypotheses derived from Prospect Theory, the negative condition prompted more extensive processing and more defensive processing. Participants in the negative condition were also more likely to consider taking protective action. Findings are discussed in the context of the health-framing literature.

Perceived likelihood of experiencing a desirable versus undesirable outcome.

In each of 6 studies, some participants were informed that the consumption of certain foods prevents diet-related heart disease; then, they estimated their likelihood of avoiding the disease. Others were informed that failing to consume the same foods contributes to diet-related heart disease; then, they estimated their likelihood of developing the disease. The undesirable outcome was always perceived as less likely than the desirable one. The findings are contrasted with those reported by Bilgin. The difference between the two sets of findings may point to the role event controllability plays in the generation of optimism via motivated reasoning.

When does event valence affect unrealistic optimism?

"Unrealistic optimism" (UO) has been found to be greater for negative (i.e. undesirable) than for positive (i.e. desirable) events. In two studies, we tested whether this "valence effect" is explicable in terms of motivational processes. In each case, participants were students (n = 159 in Study 1, n = 90 in Study 2), UO for the same health event was measured, and valence was manipulated by framing the event either negatively or positively. The degree to which the event would be expected to evoke concern was varied by manipulating the ease with which it could be avoided (Study 1) or the severity of its consequences (Study 2). A similar pattern of results was found in each study: the valence effect was exhibited in the condition where the event would have evoked concern, but not in the condition where it would have evoked little concern. The findings are in accord with an explanation of the valence effect in motivational terms. Implications for health education are discussed.

Trait valence and the better-than-average effect.

People tend to regard themselves as having superior personality traits compared to their average peer. To test whether this "better-than-average effect" varies with trait valence, participants (N = 154 students) rated both themselves and the average student on traits constituting either positive or negative poles of five trait dimensions. In each case, the better-than-average effect was found, but trait valence had no effect. Results were discussed in terms of Kahneman and Tversky's prospect theory.

Event valence and estimates of own, average person's, and randomly chosen person's risk.

People typically believe they have a lower likelihood of experiencing negative events and a greater likelihood of experiencing positive events than does the average person. This effect is greater for negative than positive events. It has been proposed that this is a by-product of a tendency for estimates of the average person's likelihood to increase with the size of the group concerned. If so, event valence should affect estimates of the average person's likelihood, but not estimates of one's own likelihood or estimates of the likelihood of a person selected at random. These predictions were tested for a single event using a student sample (N = 113). Results were not in accord with the proposal. An explanation in terms of motivational processes is offered instead.

Explaining the effect of event valence on unrealistic optimism.

People typically exhibit 'unrealistic optimism' (UO): they believe they have a lower chance of experiencing negative events and a higher chance of experiencing positive events than does the average person. UO has been found to be greater for negative than positive events. This 'valence effect' has been explained in terms of motivational processes. An alternative explanation is provided by the 'numerosity model', which views the valence effect simply as a by-product of a tendency for likelihood estimates pertaining to the average member of a group to increase with the size of the group. Predictions made by the numerosity model were tested in two studies. In each, UO for a single event was assessed. In Study 1 (n = 115 students), valence was manipulated by framing the event either negatively or positively, and participants estimated their own likelihood and that of the average student at their university. In Study 2 (n = 139 students), valence was again manipulated and participants again estimated their own likelihood; additionally, group size was manipulated by having participants estimate the likelihood of the average student in a small, medium-sized, or large group. In each study, the valence effect was found, but was due to an effect on estimates of own likelihood, not the average person's likelihood. In Study 2, valence did not interact with group size. The findings contradict the numerosity model, but are in accord with the motivational explanation. Implications for health education are discussed.

Confidence in judgments of comparative, own, and average person's risk.

Unrealistic optimism is often assessed using a single question asking people to estimate their own risk compared to that of the average person like them. However, it has been proposed that such estimates of comparative risk are based mainly just on estimates of own risk. In two studies (n=80 and n=65), students gave estimates of comparative, own, and average person's risk and rated their confidence in these estimates. Confidence was lower for estimates of average person's risk than for estimates of own and comparative risk, which were given with equal confidence. Results were in accord with the proposal that judgments of comparative risk derive principally from judgments of own risk.

Changing perception of average person's risk does not suffice to change perception of comparative risk.

The direct method of assessing "unrealistic optimism" employs a question of the form, "Compared with the average person, what is the chance that event X will occur to you?" It has been proposed that when individuals construct their responses to this question (direct-estimates) they focus much more strongly on estimates of their own risk (self-estimates) than on estimates of the average person's risk (other-estimates). A challenge to this proposal comes from findings that interventions that alter other-estimates also change direct-estimates. Employing a novel intervention technique, we tested the possibility that such interventions may indirectly also change self-estimates and that this is what accounts for their effect on direct-estimates. Study 1 (n = 58) showed that an intervention which was designed to (and did) affect other-estimates also affected self-estimates, while Study 2 (n = 101) showed that it affected direct-estimates. Study 3 (n = 79) confirmed that we could modify the intervention so as to maintain the effect on other-estimates, but eliminate that on self-estimates. Study 4 (n = 112) demonstrated that when this was done, there was no longer any effect on direct-estimates. The findings are consistent with the proposal that direct-estimates are constructed largely just out of self-estimates. Implications for heath education programs are discussed.

Unrealistic optimism and event threat.

Individuals typically exhibit "unrealistic optimism" (UO), the belief that they are less likely than the average person to experience a negative event. This may be because, fearing the event, they try to reassure themselves by distorting their reasoning to conclude that they are at comparatively little risk. If this is so, the greater the "event threat" (i.e., the more serious the event's consequences and/or the greater the likelihood that those consequences will be experienced), the more reassurance should be required, and the greater the UO that should be observed. This prediction was tested in a study in which students (N = 148) were informed about a type of heart disease that could develop in later life due to inadequate diet when young. The risk attributable to diet was stated to be either slight (low-threat condition) or great (high-threat condition). Participants were asked to rate their own risk and that of the average student of developing the disease; question order was counterbalanced. The effects of event threat and question order were found to interact: event threat affected UO in the predicted way, but only when the question about own risk came first. The results are explained in motivational terms. Implications for health education are discussed.

The link between judgments of comparative risk and own risk: further evidence.

Individuals typically believe that they are less likely than the average person to experience negative events, a phenomenon termed "unrealistic optimism". The direct method of assessing unrealistic optimism employs a question of the form, "Compared with the average person, what is the chance that X will occur to you?". However, it has been proposed that responses to such a question (direct-estimates) are based essentially just on estimates that X will occur to the self (self-estimates). If this is so, any factors that affect one of these estimates should also affect the other. This prediction was tested in two experiments. In each, direct- and self-estimates for an unfamiliar health threat - homocysteine-related heart problems - were recorded. It was found that both types of estimate were affected in the same way by varying the stated probability of having unsafe levels of homocysteine (Study 1, N=149) and varying the stated probability that unsafe levels of homocysteine will lead to heart problems (Study 2, N=111). The results are consistent with the proposal that direct-estimates are constructed just from self-estimates.

Order of question presentation and correlation between judgments of comparative and own risk.

Unrealistic optimism is often assessed using a single question asking for an estimate of comparative risk. However, it has been proposed that individuals treat such a question essentially as though it were only about their own risk. This proposal leads to the prediction that, when the questions about own risk and comparative risk are asked in sequence, the correlation between the resulting estimates should be lower if the question about own risk comes first than if the question about comparative risk comes first. This prediction was tested using a student sample (N=68). Participants answered the two types of question in sequence, with order of presentation being counterbalanced. Results were in accord with the prediction. Possible reasons are advanced for individuals' answering questions about comparative risk as if the questions concerned their own risk.

Event valence and unrealistic optimism: further evidence.

Unrealistic optimism is assessed using either a single question, the rating of own likelihood of experiencing an event compared to that of the average person, or two questions, separate rating of own likelihood and that of the average person. The effect of event valence on unrealistic optimism was studied in a sample of 175 students using the two-question measure. Valence was manipulated to be positive, i.e., outcome was desirable, or negative, i.e., outcome was undesirable, by 'framing' the same event appropriately. Unrealistic optimism was greater for negative than positive valence. The effect was of the same direction and magnitude as that found by Gold and Martyn (2003) using the single-question measure. The relationship between event valence and unrealistic optimism does not depend on whether unrealistic optimism is assessed with one or two questions.

Event valence and unrealistic optimism.

The effect of event valence on unrealistic optimism was studied. 94 Deakin University students rated the comparative likelihood that they would experience either a controllable or an uncontrollable health-related event. Valence was manipulated to be positive (outcome was desirable) or negative (outcome was undesirable) by varying the way a given event was framed. Participants either were told the conditions which promote the event and rated the comparative likelihood they would experience it or were told the conditions which prevent the event and rated the comparative likelihood they would avoid it. For both the controllable and the uncontrollable events, unrealistic optimism was greater for negative than positive valence. It is suggested that a combination of the 'motivational account' of unrealistic optimism and prospect theory provides a good explanation of the results.

Contrasting the ironic monitoring and motivational explanations of postsuppressional rebound.

Suppressing a thought often results in postsuppressional rebound, that is, a subsequent increase in the incidence of the suppressed thought. The present study was dcsigned to distinguish between two explanations of rebound: Wegner's 1994 ironic monitoring theory and Liberman and Forster's 2000 motivational account. Participants (99 Deakin University students) first suppressed, then expressed, thoughts of a white bear. In some conditions, a delay--presented as occurring either intentionally or unintentionally--between suppression and expression was introduced. In other conditions, participants concurrently completed a memory task and were encouraged to antribute the difficulty of suppression either to this task or to the requirement of suppression. An intentional delay, but not an unintentional delay, reduced rebound, while attributing difficulty to the suppression requirement was associated with greater rebound than was attributing it to the memory task. The results are interpreted as supporting Liberman and Forster's motivational account of rebound.