Durability Bias in Affective Forecasts

What Mechanisms Cause the Durability Bias?

The four studies described here revealed a durability bias in affective forecasts for negative events. Although the asymmetry between the positive and negative durability bias suggests that immune neglect may have played a role in producing the durability bias in the first three studies, other factors were undoubtedly at work in these studies too. For example, numerous events transpire in the month that follows an election or a tenure decision, and the failure to consider those events when making affective forecasts (focalism) may well have played a role in Forecasters’ mispredictions (see Wilson et al., 1998). Because several mechanisms were operating at once and because we did not include design features that would uniquely implicate any one of them, the election and tenure studies established the durability bias as a phenomenon without isolating its causes.

The job interview study was designed to distinguish causal mechanisms by precluding misconstrual and focalism. We precluded misconstrual by making sure that Forecasters could imagine every detail of the event correctly. If Forecasters failed to predict how they would feel some time after the event occurred, it was not because they failed to understand what the event entailed. Similarly, we precluded focalism by asking Forecasters to predict how they would feel a very short time after a focal event took place, and we made sure that no significant nonfocal events happened in the interim. If Forecasters failed to predict how they would feel a few minutes after the event occurred, it was not because Experiencers forgot about the focal event or because something unexpected happened in the interval between the focal event and the Experiencers’ reports. These features of our experimental designs allow us to say with confidence that the durability bias does not require that people misunderstand the nature of the events about which they are making forecasts, nor that people fail to consider the nonfocal events that transpire after the focal event. Misconstrual and focalism may be sufficient, but they are not necessary, causes of the durability bias.

But what of the other mechanisms? We did not attempt to preclude undercorrection, inaccurate theories, and motivational distortion, and thus any or all of these mechanisms may have played a role in producing the durability bias in the first study described here. None, however, can account for the pattern of data that uniquely implicates immune neglect in the job interview study. People may fail to correct their inferences about their initial reactions by taking into account the effects of the passage of time (undercorrection), they may motivate themselves to work harder by making overly dire predictions about the emotional consequences of failure (motivated distortion), or they may simply have inappropriate ideas about how much certain things hurt (inaccurate theories). Any one of these facts might explain why participants overestimated the duration of their negative affect, but only immune neglect explains why forecasters failed to distinguish between events that, according to experiencers’ reports, facilitated or inhibited the immune system. In short, several causal mechanisms may have been operating in the job interview study, but immune neglect certainly was operating. We do not wish to claim that the durability bias was caused solely by immune neglect in any of our studies; rather, we merely wish to claim that immune neglect was clearly a causal factor in the job interview study.