Dirty socks

One day two young athletes each play much better than usual in a game. After the game, both children refuse to allow their parents to wash their socks or underwear. They are afraid that the soap and water will remove the good luck of the day. One set of parents complies; the other does not. In their next games, the first child does quite well again, but the other child plays poorly. Could the placebo effect help explain their performance in the second game? Explain why you think the placebo effect is or is not a good way to analyze the situation.