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MARY MAYS: When we first heard about John de Castro's studies, we decided to see if we could get the effect in the lab Herb Meiselman and I agree that it is nice to get both field-based and lab-based studies agreeing, and this has never really been done in a systematic way.
So, we fed people—either alone or in groups of four—a spaghetti, salad, and dessert dinner. They were all the same sex. When we began, we put people in groups where they did not know one another because we did not want interference. We got no effects at all, no enhancement.
Then when we decided to test friends in both male and female groups, we got a 50 percent increase in both genders.
However—and this is something we did not make a lot of—it all practically increased dessert consumption. I know you did not find any differences in the nutrient composition, but practically all the social effects were increased consumption of dessert.
JOHN DE CASTRO: These are interesting findings, and they fit well with the comparison type finding I have reported. However, social facilitation may be affecting different components of the meal in different contexts.