MindsetMatters: Mindset Matters

Description Format Details Source


Data from a study of perceived exercise with maids


A dataset with 75 observations on the following 14 variables.

Cond Treatment condition: 0=uninformed or 1=informed
Age Age (in years)
Wt Original weight (in pounds)
Wt2 Weight after 4 weeks (in pounds
BMI Original body mass index
BMI2 Body mass index after 4 weeks
Fat Original body fat percentage
Fat2 Body fat percentage after 4 weeks
WHR Original waist to hip ratio
WHR2 Waist to hip ratio
Syst Original systolic blood pressure
Syst2 Systolic blood pressure after 4 weeks
Diast Original diastolic blood pressure
Diast2 Diastolic blood pressure after 4 weeks


In 2007 a Harvard psychologist recruited 75 female maids working in different hotels to participate in a study. She informed 41 maids (randomly chosen) that the work they do satisfies the Surgeon General's recommendations for an active lifestyle (which is true), giving them examples for how why their work is good exercise. The other 34 maids were told nothing (uninformed). Various chacteristics (weight, body mass index, ...) were recorded for each subject at the start of the experiment and again four weeks later. Maids with missing values for weight change have been removed.


Crum, A.J. and Langer, E.J. (2007). Mind-Set Matters: Exercise and the Placebo Effect, Psychological Science, 18:165-171. Thanks to the authors for supplying the data.

Lock5Data documentation built on May 31, 2017, 3:56 a.m.