The Impact Bias: Why We Overestimate the Emotional Impact of Future Events


This scenario would provoke anxiety in many of us, but research finds that we tend to overestimate the emotional impact of future events.

People often overestimate the intensity and duration of their emotional reactions to future events. This tendency is called the impact bias, which is just one of many cognitive biases. Because of the impact bias, people fail to make the right decisions about their emotional reactions to future events.

In a new review by Wilson & Gilbert (2013), the authors state that the impact bias is alive and well (which is actually the title of their paper). This post provides a number of examples, and it examines the causes, of the impact bias.

Examples of the impact bias

Wilson & Gilbert (2005) highlight the following research findings:

  • “College students overestimated how happy or unhappy they would be after being assigned to a desirable or undesirable dormitory.”
  • “People overestimated how unhappy they would be two months after the dissolution of a romantic relationship.”
  • “Untenured college professors overestimated how unhappy they would be five years after being denied tenure.”
  • “Women overestimated how unhappy they would be upon receiving unwanted results from a pregnancy test.”

Halpern & Arnold (2008) emphasize that patients poorly predict their future ability to adapt to adversity such as health declines and disability. Patients fail to envision their own capacities to adapt to declines in health: ‘People without a given disability rate their expected quality of life significantly lower than those actually living with that disability’ (p. 1708).

In an experiment by Gilbert & Ebert (2002),  the participants (photography students) believed that having the opportunity to change their minds about which prints to keep would not influence their liking of he prints. However, it did influence their liking of the prints.

The authors conclude that the participants behaved in ways that did not optimize their happiness and well-being because of errors in affective forecasting.

In a study by Eastwisk and colleagues (2008), the authors found that people mispredicted how distressed they would be after they had broken up with their romantic partner. At the time of the break up, the participants were not as distressed as they had predicted two weeks earlier.

Their predicted distress ratings remained substantially higher than their actual distress even several months after the breakup. The impact bias was most pronounced for individuals who (1) were more in love with their partners, (2) who felt it was less likely that they would soon begin a new relationship, and (3) who played less of a role in initiating the breakup.

Causes of the impact bias

Here are two causes of the impact bias (Wilson & Gilbert, 2005):

  • Focalism: People tend to overestimate how much they will think about the event in the future, and at the same time, they underestimate the degree to which other events will influence their thoughts and feelings. So people get too focused on a particular event and its emotional impact
  • Sense-making: People are brilliant sense-makers, and by making sense of events, people adapt emotionally to them. However, people fail to recognize how fast they will make sense of novel or unexpected events once they happen, and for this reason, people overestimate their emotional reactions to such events
Photo: mari ce