Okay, here's what I find even more interesting about that study:
"When the moviegoers were asked if they thought they ate more because of the size of the container, 77 percent of those given the large tubs said they would have eaten the same amount if given a medium container. "This means that the moviegoers were unaware that the exceptional amount they ate was due to the size of the container,"
http://www.sciencedaily.com/releases...1110221344.htm
I am a social psychologist, and it's this kind of result that simply fascinates me. We are just so often unaware of what affects our behavior!!