Mimickry outweighs money in rock, paper, scissors

Research at University College London suggests humans mimicking others is a largely involuntary response. The findings come from an experiment involving “rock paper scissors”.

The experiment involved participants taking part in a series of games. The reason for using rock paper scissors was to put any tendency to mimic others to the test: while the winning strategy is dependent on the opponent, one thing that is guaranteed is that mimicking an opponent will not produce a win.

The experiment involved 45 people being split into groups of three, with each group competing on a round robin basis (meaning 45 total pairings, though this was reduced to 42 as one group had a procedural error.)

Each pair of participants played 60 games against one another: 20 with the first player blindfolded, 20 with the second player blindfolded and 20 with both players blindfolded. The player with the best result over the 60 games won a cash bonus.

Among the games where both players were blindfolded, the results were precisely the same as would be expected by chance: one third of games (33.3%) ended in a draw. However, in the games where only one player was blindfolded, 36.3% ended in a draw: not a dramatic difference, but one the researchers believe is statistically significant.

Breaking down the figures, it turned out that the games were notably more likely to end in a draw when the blindfolded player chose scissors or rock than if they chose paper. And across the contests, the sighted player was actually slightly more likely to lose.

The research results don’t note the hand position required when about to make a selection, or if the traditional three-shakes rule was in effect. If the players had to use clenched fists (that is, the rock position) you might expect rock to be the position least likely to give a signal to the opponent.

Still, the conclusion the researchers made is that the higher proportion of draws with one player blindfolded suggests that to some extent the sighted player’s instinct to imitate an opponent overcame the intent to win the game. The researchers say “our results challenge the tendency in economic and game theory to ignore, or abstract away, the physical aspects of social interaction.”

Of course, the research doesn’t answer a major linguistic question: not “Why do some people say ‘rock’ and others ‘stone’?” but rather “Why does this decision affect the ordering of the phrase from ‘rock paper scissors’ to ‘scissors paper stone’?”