Simulation Heuristic

What is the simulation heuristic?

The simulation heuristic is a mental shortcut in which people judge an outcome partly by how easily they can construct a sequence of events that produces it. It can shape judgments about what might happen and what could have happened differently.

Imagine planning an outdoor party. You can picture the weather changing, everyone rushing inside, and the food getting soaked. The sequence comes together quickly. That makes rain feel worth worrying about, but it does not tell you how likely rain is on that date.

Building a scenario, not just recalling an example

In their 1982 chapter, Daniel Kahneman and Amos Tversky distinguished constructing a scenario from retrieving instances. The availability heuristic often involves examples that readily come to mind. Simulation involves assembling a possible sequence, including events you have never experienced.

For the party, remembering three rainy birthdays supplies instances. Imagining how tomorrow's party could be disrupted supplies a scenario. Both can inform a judgment, but they provide different kinds of information.

How a plausible story can mislead

Suppose the party is in a region where rain is rare in that month. A detailed rain scenario does not cancel that background information. You would still want the forecast. Conversely, finding a disaster difficult to imagine does not establish that it is unlikely: you may simply know too little about how it could occur.

The same distinction matters when looking backward. As a hypothetical example, imagine missing a train by a minute. Leaving the house a little earlier gives you an easy alternative sequence ending at the platform on time. Missing it by an hour requires a larger change. That difference in ease of imagining an alternative is separate from the practical consequences of missing the train.

Use the scenario to identify a question

A scenario can reveal something worth checking. For the party, ask how many guests can fit indoors and whether moving the food would be difficult. Then assess the chance of rain using relevant evidence. The imagined sequence helps identify what would matter if the event occurred; it does not, by itself, establish the probability.

References

Kahneman, D., & Tversky, A. (1982). The simulation heuristic. In D. Kahneman, P. Slovic, & A. Tversky (Eds.), Judgment under Uncertainty: Heuristics and Biases (pp. 201–208). Cambridge University Press. https://doi.org/10.1017/CBO9780511809477.015