The impact bias, a form of which is the durability bias, in affective forecasting, is the tendency for people to overestimate the length or the intensity of future feeling states.
Other explanations for the occurrence of the impact bias are the following:
Misconstrual of future events When predicting how an experience will impact us emotionally, events which have not been experienced are particularly difficult. Often how we think an event may be like does not relate to how the experience is actually like.
Inaccurate theories People have created cultural theories and had experiences that greatly influence beliefs of how an event will affect us. For example, our culture has emphasized a correlation between wealth and happiness, however despite this belief; money does not necessarily bring happiness.
Motivated Distortions When faced with a negative event people may have forecasts that are overestimated and can evoke either comfort or fear in the present. The overestimation however can often be used to soften the effects of an event or make it easier by the reality not being as extreme as the forecasted impact.
Under correction (anchoring and adjustment) People anchor their prediction on how they currently feel and never accurately adjust their prediction
Focalism Often when making a prediction of the impact of an event people focus solely on the event in question. This method ignored the fact that other events will occur that influence our reactions.
Immune Neglect We have unconscious psychological processes such as ego defense, dissonance reductions, self-serving biases, etc that will cushion the effects of a negative event.