WORCHEL, LEE, AND ADEWOLE (1975) asked people to rate chocolate chip cookies. They put 10 cookies in one jar and two of the same cookies in another jar. The cookies from the two-cookie jar received higher ratings—even though the cookies were exactly the same! Not only that, but if there were a lot of cookies in the jar, and then a short time later most of the cookies were gone, the cookies that were left received an even higher rating than cookies that were in a jar where the number of cookies didn’t change.
[From Neuro Web Design by Susan Weinschenck.]