Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.

This study investigated the effect on observer responses of the presence/absence of information about medical evidence for pain and psychosocial influences on the patient's pain experience. Additionally, the moderating role of the patient's pain expressions and the mediating role of the observer's belief in deception and evaluation of the patient was examined. Sixty-two participants were presented with videos of 4 patients, each accompanied by a vignette describing the presence or absence of both medical evidence for the pain and psychosocial influences on the patient's pain. Participants estimated patients' pain and rated their own sympathy and inclination to help; they re-estimated patients' pain when the patient's self-report of pain was provided. Finally, participants evaluated each patient as positive or negative and the likelihood that the patient was feigning pain. Participants gave lower ratings on pain, sympathy, and help when medical evidence was absent. Further, in the presence of psychosocial influences, participants took patients' self-reported pain less into account. Next, only for patients expressing high-intensity pain, information about both medical evidence and psychosocial influences was taken into account. Finally, the observer's evaluation of the patient and his/her belief in deception fully, respectively partially, explained the effect of medical evidence. The results indicate that discounting pain in the absence of medical evidence may involve negative evaluation of the patient. Further, the patient's pain expression is a moderating variable, and psychosocial influences negatively impact the degree to which patients' self-reports are taken into account. The results indicate that contextual information impacts observer responses to pain.