{Reference Type}: Journal Article {Title}: Risky effort. {Author}: Mason A;Sun Y;Simonsen N;Madan CR;Spetch ML;Ludvig EA; {Journal}: Cognition {Volume}: 251 {Issue}: 0 {Year}: 2024 Oct 20 {Factor}: 4.011 {DOI}: 10.1016/j.cognition.2024.105895 {Abstract}: Decision-making involves weighing up the outcome likelihood, potential rewards, and effort needed. Previous research has focused on the trade-offs between risk and reward or between effort and reward. Here we bridge this gap and examine how risk in effort levels influences choice. We focus on how two key properties of choice influence risk preferences for effort: changes in magnitude and probability. Two experiments assessed people's risk attitudes for effort, and an additional experiment provided a control condition using monetary gambles. The extent to which people valued effort was related to their pattern of risk preferences. Unlike with monetary outcomes, however, there was substantial heterogeneity in effort-based risk preferences: People who responded to effort as costly exhibited a "flipped" interaction pattern of risk preferences. The direction of the pattern depended on whether people treated effort as a loss of resources. Most, but not all, people treat effort as a loss and are more willing to take risks to avoid potentially high levels of effort.