The Incidental Effects of Sadness on the Planning Fallacy

The planning fallacy is a judgment bias in which people underestimate the time it takes to compete a task, even though they are aware that similar projects have taken longer than what they currently estimate (Kahneman & Tversky, 1979). Determinants of time estimation hinge on one’s depth of processing and sense of uncertainty regarding the task (Griffin, et al., 1990); two domains that are relevant to the experience of sadness. Combined with evidence that incidental emotions carry over to affect normatively unrelated scenarios (Lerner, & Loewenstein, 2003), it is posited that sadness will have an effect in time estimations. Specifically, it is hypothesized that sadness will attenuate the planning fallacy because of its tendency to encourage systematic thought. The present study randomly divided participants into either a sadness or neutral condition and asked them to estimate how long it would take to complete a formatting task on the computer. It then asked participants to complete the task. Results replicated the planning fallacy but did not support the hypothesis of a sadness carry-over effect. The discussion considers limitations of the present study and proposes future directions