When does event valence affect unrealistic optimism?

Abstract

“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. Ineach 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 inthe 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.

Keywords:

• unrealistic optimism
• valence effect
• motivational account
• prospect theory

Notes

1. The significant effect of valence on UO when efficacy was low was due to an effect on estimates of own risk (for negative valence, M = 3.03, SD = 1.27; for positive valence, M = 3.88, SD = 1.25; F(1,156) = 8.34, p = 0.004); there was no significant effect on estimates of the average person's risk (for negative valence, M = 4.18, SD = 1.11; for positive valence, M = 3.88, SD = 0.93; F(1,156) = 1.44, p = 0.232).

2. The significant effect of valence on UO when severity was high was contributed to by non-significant differences both in estimates of own risk and estimates of the average person's risk. Estimates of own risk were somewhat lower for negative than positive valence (M = 3.05, SD = 1.00 vs. M = 3.55, SD = 1.26; F(1,87) = 2.01, p = 0.160), while estimates of the average person's risk were somewhat higher for negative than positive valence (M = 4.00, SD = 1.02 vs. M = 3.59, SD = 0.91; F(1,87) = 2.31, p = 0.132).

3. Participants were 74 undergraduate students attending Deakin University. Controllability ratings were given on a seven-point Likert scale, with anchors of 1: “not at all within their control” and 7: “very much within their control”. Mean ratings were 4.81 (SD = 0.98) for negatively framed information, 4.63 (SD = 1.10) for positively framed information, 4.64 (SD = 0.99) for developing heart disease, and 4.79 (SD = 1.04) for avoiding heart disease. A 2 X 2 ANOVA indicated no main effects of the way the information was framed (F(1,70) = 0.57, p = 0.453) or the way the controllability question was asked (F(1,70) = 0.408, p = 0.525) and no interaction between the two (F(1,70) = 0.165, p = 0.685).