Why You Are Always in the Slow Line

Christmas shopping can be tough- elbowing your way past clusters of women scrambling to get the latest hot toy or an item on sale. But the final indignation is trying to check out- and picking what you think to be the fastest line. You check the items people are purchasing preferring to get behind an emptier shopping basket than a full one, and if they have a credit card rather than a checkbook in hand, you probably think you might be able to identify the fast line. But is it really? And what do telephones have to do with long lines at the cashiers? Science can help!