Exerting effort for non-instrumental information under risk.

People constantly invest effort to seek information in everyday life, even if the information is of no instrumental value for the decision at hand. However, the mechanism underlying people’s willingness to exert effort in exchange for information remains unclear. Previous work has suggested that desirability and uncertainty are two key factors influencing information-seeking, but few studies have tested if these factors are important when exerting physical effort in exchange for information. Additionally, it remains unknown whether different kinds of uncertainty, i.e., risk and ambiguity, have differential impacts. In the current study, we developed a novel information-seeking task to quantify the value of non-instrumental information using incentive-compatible physical effort to examine how effort changes as a function of desirability and uncertainty. Across two studies (N = 123), we found that people’s willingness to exert effort is positively associated with outcome expected value under both risk and ambiguity. Additionally, people exert more effort when outcome distribution uncertainty increases in risky situations, but are insensitive to ambiguity, except when facing extreme ambiguity. Our results demonstrate an unexpected dissociation. Humans will engage in effort-based information-seeking, even for non-instrumental information, when facing risk. In contrast, they show a much lower willingness to expend effort to resolve non-instrumental ambiguity.