What is affective forecasting in simple terms?

It is guessing in advance how happy or sad something will make you. People generally expect those feelings to be stronger and to last longer than they actually do.

Why do affective forecasts often go wrong?

Two main reasons are immune neglect, forgetting our own ability to adapt to bad events, and focalism, thinking only about one event and forgetting the rest of daily life. Some researchers note, however, that the errors may have been exaggerated by measurement methods.

Affective Forecasting

🧠 Psychology By CampusDown Wiki Editorial Team Last updated October 27, 2026

Affective forecasting is the process of predicting which emotions a future event will evoke, how intensely and for how long. The psychologists Timothy Wilson and Daniel Gilbert studied it systematically from the late 1990s. People generally predict the direction of their feelings correctly but often overestimate their intensity and duration, a tendency called the impact bias, and the concept is important in happiness and decision-making research.

Contents

1. Concept and the impact bias
2. Why forecasts go wrong
3. Significance and critiques
4. FAQ
5. References

Concept and the impact bias

Wilson and Gilbert (2003) divided affective forecasting into predicting the valence, the specific emotions, the intensity and the duration of feelings. People are good at predicting that a promotion will feel good and a breakup bad, but tend to overestimate how strong and how long-lasting those feelings will be. This is called the impact bias, and overestimating duration specifically is called the durability bias. Brickman, Coates and Janoff-Bulman (1978) reported that lottery winners were not much happier in everyday pleasures than controls, a starting point for discussions of hedonic adaptation, the tendency to adapt to major events faster than expected.

Why forecasts go wrong

Gilbert and colleagues (1998) proposed immune neglect. People have a psychological immune system that reinterprets and rationalizes bad events, but they fail to take it into account when forecasting and therefore expect distress to last longer. Wilson and colleagues (2000) proposed focalism: people think only of the focal event and forget the many other everyday events that will also occur, so they overestimate its impact. Schkade and Kahneman (1998) found that students in the Midwest and California both predicted Californians would be happier, yet life satisfaction did not differ much, a phenomenon they called the focusing illusion. Gilbert and colleagues (2004) reported that people also overpredict the regret they will feel after narrowly missing a train.

Significance and critiques

Affective forecasting matters because people choose what to want on the basis of anticipated feelings. Wilson and Gilbert (2005) explained that forecasting errors can lead people to choices that actually bring less happiness, for example by overestimating the happiness a bigger house or higher salary will bring, or by overestimating the pain of something feared and avoiding a necessary choice. Levine and colleagues (2012), however, argued that the intensity bias may have been inflated by the way many studies asked participants about feelings toward a specific event, and that forecasts can be fairly accurate when questions are changed. The concept is treated alongside optimism bias and the planning fallacy as a systematic error in how we judge the future.

FAQ

What is affective forecasting in simple terms?: It is guessing in advance how happy or sad something will make you. People generally expect those feelings to be stronger and to last longer than they actually do.
Why do affective forecasts often go wrong?: Two main reasons are immune neglect, forgetting our own ability to adapt to bad events, and focalism, thinking only about one event and forgetting the rest of daily life. Some researchers note, however, that the errors may have been exaggerated by measurement methods.

Sources reviewed: 2026-10-26

References

Wilson, T. D., & Gilbert, D. T. (2003). Affective forecasting. Advances in Experimental Social Psychology, 35, 345–411. The field's flagship review — the fastest way to get the concept and its main errors in one read.
Gilbert, D. T., Pinel, E. C., Wilson, T. D., Blumberg, S. J., & Wheatley, T. P. (1998). Immune neglect: A source of durability bias in affective forecasting. Journal of Personality and Social Psychology, 75(3), 617–638. Shows people underestimate their own psychological immune system — key to why we overpredict how long bad events will hurt.
Wilson, T. D., Wheatley, T., Meyers, J. M., Gilbert, D. T., & Axsom, D. (2000). Focalism: A source of durability bias in affective forecasting. Journal of Personality and Social Psychology, 78(5), 821–836. Introduces focalism — fixating on one event and forgetting everything else in daily life — another source of forecasting error.
Schkade, D. A., & Kahneman, D. (1998). Does living in California make people happy? A focusing illusion in judgments of life satisfaction. Psychological Science, 9(5), 340–346. The famous California study on the focusing illusion — a good read when thinking about moves or job changes.
Brickman, P., Coates, D., & Janoff-Bulman, R. (1978). Lottery winners and accident victims: Is happiness relative? Journal of Personality and Social Psychology, 36(8), 917–927. The classic lottery-winner study; helpful background on hedonic adaptation.
Gilbert, D. T., Morewedge, C. K., Risen, J. L., & Wilson, T. D. (2004). Looking forward to looking backward: The misprediction of regret. Psychological Science, 15(5), 346–350. Shows we overpredict regret after narrowly missing a train — useful on mispredicting regret.
Levine, L. J., Lench, H. C., Kaplan, R. L., & Safer, M. A. (2012). Accuracy and artifact: Reexamining the intensity bias in affective forecasting. Journal of Personality and Social Psychology, 103(4), 584–605. Re-examines whether the intensity bias is partly a measurement artifact — the field's main critical voice.
Wilson, T. D., & Gilbert, D. T. (2005). Affective forecasting: Knowing what to want. Current Directions in Psychological Science, 14(3), 131–134. A short, readable summary — good before tackling the longer review.

Reports and materials that use this theory (Korean)

There are no materials dedicated to this theory yet, but you can search related reports in the CampusDown library (Korean).

Find more reports · Search '정서 예측' on CampusDown →

Optimism biasOptimism bias is the unrealistic belief that good events are more likely, and bad events less likely, to happen to oneself than to others.🧠 Psychology Planning fallacyKahneman and Tversky's planning fallacy, the thesis-deadline study, famous cost overruns like the Sydney Opera House, and fixes that work: taking the outside view and reference class forecasting.🧠 Psychology Hyperbolic DiscountingWhat hyperbolic discounting is: discounting near-term delays steeply and distant ones less, its origins, preference reversals and time inconsistency, the quasi-hyperbolic model, naive and sophisticated agents, commitment and evidence.📈 Economics Hindsight biasHindsight bias is the tendency, after learning an outcome, to see it as having been more predictable than it was: the “I knew it all along” effect.🧠 Psychology Negativity BiasWhat negativity bias is: negative information and events weigh more heavily than equally sized positive ones. Covers Baumeister et al.'s 'bad is stronger than good', Rozin and Royzman's four elements, loss aversion, and research on news and politics.🧠 Psychology

Latest ArticlesView all ›

New guides for college study and assignments (Korean)

This article was last updated on October 27, 2026. It is based on widely recognized original works and textbooks; when citing it in a paper, please check the original sources listed in the references.