You never know when someone might challenge you to a game of rock-paper-scissors. Something as important as riding shotgun or not having to pick up a check might be on the line, so you need to have more than just luck on your side.
Scientists at Zhejiang University in China have just published the results of the first large-scale study of the classic game, The Washington Post reports, and they discovered that most players actually follow a pattern. The researchers found that while you can't predict whether your opponent will start off by choosing rock, paper, or scissors, you can assume that if they win, in the second round they will likely use the same play. If they lost, they will probably switch "in a clockwise direction," so rock becomes paper, paper turns into scissors, and scissors morph into rock.
It appears as though players follow a cyclical pattern, which The Washington Post's Caitlin Dewey says "means sneaky players can use 'conditional response,' a reaction to a specific stimulus, in order to optimize results." The researchers are now more fascinated than ever with rock-paper-scissors. "Whether conditional response is a basic decision-making mechanism of the human brain or just a consequence of more fundamental neural mechanisms is a challenging question for future studies," they said. Catherine Garcia