Cool Psychological Research: Shifting perceptions as weight-loss and fitness strategy
Alia Crum and Ellen Langer from the Harvard Psychology department did an experiment in which they matched two groups of hotel room cleaners (84 subjects spread across seven hotels). These housekeepers get many hours of exercise per day (cleaning on average 15 rooms per day, each taking 20-30 minutes to clean; they are pressured to finish the cleaning task quickly), but do not typically think of themselves as doing exercise. The experimenters told the cleaners from four hotels that they were getting the amount of exercise the surgeon general recommends to maintain a healthy lifestyle and the ones from the other hotels were not told anything. When the researchers returned to measure the results a mere four weeks later, they found that the women who had been told they were exercising enough had lost an average of two pounds, that their blood pressure was almost 10% lower as a group and that they were significantly healthier in measures of body fat percentage, body mass index, and waist-to-hip ratio. No such changes were noted in the control group. It’s not clear whether the housekeepers who were told they were exercising enough instituted other changes that facilitated the healthier outcomes or those results were mainly due to a shift in perception. In any case, that is an amazing result for such a short follow-up.
Source: Crum, A. & Langer, E. (2007) “Mindset Matters: Exercise as a Placebo,” Psychological Science, 18, 2.
