Alice, Bob, and Sue have ten marbles between them. Whenever one kid wants another kid to take over a chore, she promises a marble in exchange. Alice doesn't like setting the table, so she promises Bob a marble if he will do it for her. Bob hates mowing the lawn, but Sue will do it for a marble. Sue doesn't like broccoli, but if she says pretty please and promises a marble, Bob will eat it off her plate when Mom isn't looking.This is an easy example - click the link at top for the full version. My longer
One day, the kids get together to brag about all the marbles they soon will have. It turns out that, between them, they are promised 40 marbles! Now that is pretty exciting. They've each promised to give away some marbles too, but they don't think about that, they can keep their promises later, after they've had time to play with what's coming. For now, each is eager to hold all the marbles they've been promised in their own hands, and to show off their collections to friends.
But then Alice, who is smart and foolish all at the same time, points out a curious fact. There are only 10 marbles! Sue says, "That cannot be. I have earned 20 marbles, and I have only promised to give away three! There must be 17 just for me."
But there are still only 10 marbles.
Suddenly, when Bob doesn't want to mow the lawn, no one will do it for him, even if he promises two marbles for the job. No one will eat Sue's broccoli for her, even though everyone knows she is promised the most marbles of anyone, because no one believes she will ever see those 17 marbles she is always going on about. In fact, dinnertime is mayhem. Spoons are placed where forks should be, and saucers used for dinner plates, because Alice really is hopeless in the kitchen. Mom is cross. Dad is cross. Everyone is cross. "But you promised," is heard over and over among the children, amidst lots of stomping and fighting. Until recently, theirs was such a happy home, but now the lawn is overgrown, broccoli rots on mismatched saucers, and no one trusts anyone at all. It's all a bit mysterious to Dad, who points out that nothing has changed, really, so why on Earth is everything falling apart?