Another illustration of our lack of self-knowledge comes from a study in which researches asked a group of college students to choose a series of snacks. Each week they had a three-hour seminar with one break that allowed participants to stretch their legs, use the bathroom, clear their heads, and have something to eat. When the professor asked the students to pick a snack for each of the next three weeks, the students picked a variety, thinking they'd get tired of the same snack each week. In contrast, another group in the same study got to choose their snack every week, and tehse students, choosing one week at a time, tended to choose the same thing each week. These two sets of participants were faced with different tasks. The students who were choosing one snack at a time simply had to ask themselves what they felt like eating at the moment. Those who were choosing for three weeks had to <i>predict</i> what they would feel like eating two or three weeks from the moment of choice.