Attempting to control blood pressure without systematic instruction: when advice is counterproductive.

The present study examined the effects of asking subjects to keep their blood-pressure level low while in the presence of an arousing stimulus. It was hypothesized that, without assistance, subjects' attempts to keep their blood pressure low would actually produce increases in blood pressure, as compared to subjects simply asked to respond naturally to the arousing stimulus. Fifty male subjects watched a videotape containing a neutral (nonarousing) section and an erotic section while their blood pressure was recorded by means of an automated blood-pressure monitoring device. Some of the subjects were asked to relax and keep their blood pressure low during the erotic parts of the videotape; the rest of the subjects were asked to respond naturally. The results confirmed the hypothesis, suggesting that urging people to relax can be counterproductive if they do not also receive systematic instruction on how to relax or control blood pressure. Implications for health messages in the mass media and physician-patient interactions are discussed.