What Was Tested?

In two separate experiments, researchers told people they had either the good or bad version of a gene that affects aerobic exercise, or the good or bad version of a gene that affects appetite and satiety.

Methodology

The subjects underwent one testing session before being told they had either good or bad genes, and one testing session after they were told they had either good or bad genes.

What Happened?

For some measures, the people who were told they had bad genes regressed from the first to the second testing sessions; for other measures, the people who were told they had good genes improved from the first to the second testing sessions. This was true for both objective physiological measures and subjective responses.

These results aren’t too surprising, as prior research has shown that expectancy affects both acute and chronic outcomes.