Money gained through suffering is less valuable: Pain reduces the sensitivity to outcome magnitude in monetary decision making.

Enduring pain would change individuals' behavioral preferences and neural responses in multiple decision-making tasks. Yet few studies have investigated how money's casual association with painful experience would modify people's decisions with it. It is an important and common social situation. The present study investigated how money's association with pain influences the way people make monetary decisions. Participants gambled with money that they earned in four different ways: enduring pain (Pain), randomly assigned (Random), non-painful effort task (Effort), and observing negative images (NO). Results revealed two different patterns. In the Random and Pain conditions, participants were not sensitive to the gambling risk such that they more randomly chose high- and low-risk options; the differences in FNR amplitude triggered by high- and low-risk choices were comparable on the neural level. In contrast, in the Effort and NO conditions, participants showed higher sensitivity to the magnitude and larger differences in FNR amplitudes between high- and low-risk choices. These findings suggested that pain cannot increase the subjective value of monetary gain like other non-painful efforts can do and monetary rewards may not be the optimal way to compensate for the physical suffering or loss in society.