Ethnic differences in thermal pain responses

Objective: Although numerous studies have reported ethnic differences in th e prevalence and severity of clinical pain, little is known about how these differences affect the perception of experimental pain. The present experi ment examined the effects of ethnicity (African American vs, white) on ther mal pain responses in a healthy undergraduate population. Methods: Thirty w hite subjects (16 women and 14 men) and 18 African Americans (10 women and 8 men) participated in the study. Thermal testing included evaluation of th e following: warmth thresholds, thermal pain thresholds, thermal pain toler ances, and magnitude estimates of both the intensity and unpleasantness of thermal pain (at 46 degrees, 47 degrees, 48 degrees, and 49 degrees C). Res ults: Although no group differences emerged for warmth thresholds, thermal pain thresholds, or pain intensity ratings, African Americans demonstrated lower thermal pain tolerances than whites. In addition, African Americans h ad smaller slopes and larger intercepts than whites for ratings of pain unp leasantness. Additional analyses suggested that these findings were a conse quence of group differences in thermal pain unpleasantness ratings at the l owest temperatures assessed (46 degrees and 47 degrees C); at these tempera tures, African Americans rated the stimuli as more unpleasant than whites. Finally, group differences in thermal pain tolerance and thermal pain unple asantness ratings seemed to partially account for greater self-reported dai ly pain symptoms among African Americans. Conclusions: Collectively, these findings seem to suggest ethnic differences in the perception of the affect ive-motivational dimension of thermal pain.