Process Simulation

What it is

Process simulation is one of two kinds of mental simulation that Lien Pham and Shelley Taylor set against each other in a 1999 paper in the Personality and Social Psychology Bulletin. The other kind is outcome simulation. In outcome simulation a person imagines the end state: the good grade, the finished project, the result achieved. In process simulation a person imagines how to get there: the actions, their order, and what carrying them out involves.

The distinction matters because the two feel alike and behave differently. Both are pleasant ways of thinking about a goal. Only one of them produces a plan. The paper's opening claim is that mental simulations can strengthen the links between thought and action, and the experiment was built to find out which kind does so.

Participants were college freshmen. For five to seven days before a midterm exam they were asked to simulate one of four things: the process of studying for the exam, the outcome of getting a good grade, both, or neither. The group that simulated neither did a self-monitoring task and served as the control, which means the comparison was between kinds of mental activity and not between thinking and doing nothing. According to the abstract and the publisher's summary, simulating the process increased studying and improved grades, and the grade effect was mediated by better planning and by reduced anxiety. The reported exam figures put the group that simulated only the outcome below the group that simulated only the process.

The mediators the authors report are planning and anxiety. A plausible reading, ours and not the paper's, is that a person who has run through the steps has made decisions about them in advance and has less to be anxious about when the time comes, while a person who has pictured the grade has a pleasant image and no plan.

The idea sits close to a body of work by Gabriele Oettingen on positive fantasies, in which picturing the wished-for result as already achieved predicted less effort and poorer outcomes. It also sits close to the premortem, which asks a team to imagine a plan has failed and to write the history of the failure. Each asks for the steps and the causes, and not for a picture of the end.

In effect

The midterm study

The 1999 experiment is the whole empirical basis for this page. Students rehearsed the studying and not the grade, and they studied more and earned better grades. Because the control group did a self-monitoring task, the result is not an artefact of doing something versus nothing.

The contrast with positive fantasies

Oettingen's studies of 2002 followed graduating students, students with a crush, undergraduates facing a midterm and hip-replacement patients. In each, positive fantasies about the future predicted less effort and worse outcomes, and a content analysis of the hip patients' fantasies found they tended to idealise both a perfect outcome and an effortless path to it. The fantasies were of the kind process simulation leaves out, a picture of the arrival with the route missing.

Rehearsing a decision

A decision can be treated as a short plan: choose, then carry out. Process simulation applies to the second half, the route from choosing to doing. It gives no direct help with the first half, whether the choice is a good one. The article on mental rehearsal and decisions makes that limit explicit.

What it does not say

It does not say that process simulation improves decisions. The study measured studying and exam grades, and no study cited on this page scored the quality of a decision.

It does not rest on a large body of replications. The page rests on one study of first-year students and one midterm, read here at the level of its abstract and the publisher's page summary. The full text was not available.

It does not say outcome simulation is harmful in itself. In the 1999 study the outcome-only group did worse than the process-only group on the reported figures. The stronger claims about harm come from Oettingen's correlational studies and a 2011 experiment, which concern fantasies and not this experiment's instruction to simulate a good grade.

It does not say the effect is large. No effect size is given on the pages read.

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