Beliefs about expectations moderate the influence of expectations on pain perception.

BACKGROUND Expectations congruently influence, or bias, pain perception. Recent social psychological research reveals that individuals differ in the extent to which they believe in expectation biases and that individuals who believe in expectation biases may adjust for this bias in their perceptions and reactions. That is, idiosyncratic beliefs about expectations can moderate the influence of expectations on experience. PURPOSE Prior research has not examined whether idiosyncratic beliefs about expectations can alter the degree to which one's expectations influence pain perception. Using a laboratory pain stimulus, we examined the possibility that beliefs about expectation biases alter pain responses following both pain- and placebo-analgesic expectations. METHODS Participants' beliefs about expectation biases were measured. Next, participants were randomly assigned to receive either a pain expectation or a placebo-analgesia expectation prior to a cold-pressor task. After the task, participants rated their pain. RESULTS Beliefs about expectation biases significantly influenced pain reports. Specifically, pain reports were more influenced by provided expectations the less participants believed in expectation biases (i.e., pain expectations resulted in more pain than analgesia expectations). CONCLUSIONS Beliefs about the expectation bias are an important and under-examined predictor of pain and placebo analgesia.