The effects of experimenter status and cardiovascular reactivity on pain reports

Existing evidence suggests that experimenter characteristics can influence research participants' pain reports. To examine the possibility that cardiovascular reactivity may serve as a potential mediating mechanism, blood pressure responses to stress were recorded in 117 healthy women during an arithmetic task and a subsequent cold pressor pain task. Laboratory sessions were conducted by two experimenters (i.e., a university professor and a graduate research assistant), who differed significantly on participant ratings of perceived social status. Participants tested by the university professor showed greater blood pressure responsivity to arithmetic and had higher pain tolerance and lower pain unpleasantness ratings compared to those tested by the research assistant. Further, hierarchical regression analyses indicated that blood pressure reactivity was a potential mediator of the association between experimenter status and both pain tolerance and unpleasantness, suggesting that perceived experimenter status may elicit physiological adaptations that can reduce sensitivity to painful laboratory stimuli.