Context Matters: Emotional Sensitivity to Probabilities and the Bias for Action in Cancer Treatment Decisions

Past studies have shown a commission bias for cancer treatment, a tendency to choose active treatment even when watchful waiting is less risky. This bias suggests motivations for action beyond mortality statistics, but recent evidence suggests that individuals differ in their emotional sensitivity to probabilities (ESP), the tendency to calibrate emotional reactions to probability. The current study aims to examine the role of ESP in the commission bias, specifically whether those higher in ESP are more likely to choose watchful waiting when risk probabilities align with that choice.

Participants (N = 1,055) read a scenario describing a hypothetical cancer diagnosis and chose between surgery and watchful waiting, with random assignment between versions where the mortality rate was either lower for surgery or for watchful waiting. We modeled choice using the Possibility Probability Questionnaire (PPQ), a measure of ESP, and several other individual differences in a logistic regression.

We observed a commission bias as in past studies with most participants choosing surgery both when surgery was optimal (71%) and when watchful waiting was optimal (58%). An ESP × Condition interaction indicated that the predictive role of ESP depended on condition. Those higher in ESP were more likely to choose surgery when probabilities favored surgery, β = 0.57, P < 0.001, but when probabilities favored watchful waiting, ESP had a near-zero relationship with choice, β = 0.05, P < 0.99.

The role of ESP in decision making is context specific. Higher levels of ESP predict choosing action when that action is warranted but do not predict a shift away from surgery when watchful waiting offers better chances of survival. ESP does not overcome the commission bias.

Past studies have identified a "commission bias," a tendency to choose active treatment over watchful waiting, even when mortality rate is lower for waiting.Evaluation of risk probabilities is related to individual differences in emotional sensitivity to probabilities (ESP) and has been shown to predict reactions to and decisions about health risk situations.ESP appears to be selectively factored into decision making. ESP was a robust predictor of choosing surgery when probability information supported surgery but did not predict decisions when probability information supported watchful waiting.Those who are most emotionally attuned to probabilities are just as susceptible to the commission bias as those who are less attuned.