Preconceptions are a powerful thing.
In one recent test, psychologists asked 32 volunteers to sample strawberry yogurt. To make sure the testers made their judgments purely on the basis of taste, the researchers said, they needed to turn out the lights. Then they gave their subjects chocolate yogurt. Nineteen of the 32 praised the strawberry flavor. One said that strawberry was her favorite flavor and she planned to switch to this new brand.