Abstract: The present study sought to determine the role of disappointment in the “inaction inertia” effect: The phenomenon that “one is not likely to act on an attractive opportunity after having failed to take advantage of an even more attractive opportunity”. In terms of emotional causes, different researchers have argued for a causal role of regret for this effect (reluctance to accept a current opportunity represents an attempt to avoid the experienced or anticipated regret after missing an even more attractive opportunity), but it failed to explain the inaction inertia effect under the situations when the individual's failure to obtain a previous better opportunity was due to uncontrollable factors such as others or the outside world. The current study demonstrated that disappointment (i.e., anticipated disappointment) might play an important mediational role in the inaction inertia effect when uncontrollable factors account for bypassing a better opportunity, which may be an important supplement to regret explanation.
Regret and disappointment are emotions that can be experienced in response to an unfavorable outcome of a decision. However, some regret and disappointment theorists argued that they differ with respect to the conditions under which they are felt, and how they affect decision making. They suggested that disappointment is the more general negative emotional response for unfavourable outcome, regret is experienced in cases where the disappointing outcome is attributed to the self, and the experience of disappointment can be more paralysing than that of regret and results in inertia. Totally, there is some theoretical support for the disappointment explanation of inaction inertia when the individual's missing of a previous better opportunity was due to uncontrollable factors, but the empirical evidence is missed. The present study aimed for a critical test of the disappointment explanation. Hence, two experiments did the following: Both disappointment and action likelihood were assessed to test whether factors that influenced disappointment also influenced action likelihood, and investigated whether the effects on action likelihood were mediated by disappointment. Experiment 1 focused uniquely on the escape from current experienced disappointment, and Experiment 2 further studied the avoidance of anticipated disappointment.
Experiment 1 required participants to estimate their likelihood of becoming a member of a fitness club located 30 min away and the experienced disappointment as a function of the geographical location (5 or 25 minutes) of an earlier forsaken fitness club and the responsibility (high or low) of missing the nearer fitness club. Experiment 2 used the disappointment-version scenery in which whether an initial larger discount can be acquired depends on a lottery activity, and the difference between the price of an initial and a current computer (small difference or large difference) and two level of winning probability (high or low) were manipulated in Experiment 2.
In the two experiments, the factor (Responsibility of missing a nearer fitness club in Experiment1) that did not influence disappointment had no significant effect on action likelihood, and the factors (Difference in attractiveness between an initial and a current opportunity in both experiments, and winning probability in Experiment 2) that influenced disappointment affected action likelihood. Experiment 2 further indicated that anticipated disappointment played a significant mediational role in inaction inertia. The current study introduced disappointment into this field for the first time, and demonstrated that disappointment (i.e., anticipated disappointment) plays an important role in inaction inertia when the freedom of choice and personal responsibility are reduced, which will help us understand the emotional mechanism of inaction inertia.

Key words: inaction inertia, regret, experienced disappointment, anticipated disappointment