July 20, 2011

Mimicry In Rock, Paper, Scissors

Players of the game "rock, paper, scissors" unknowingly mimic one another's hand shapes, increasing the chance of the game ending in a draw, according to new research published in the journal Proceedings of the Royal Society B this week.

The study shows that even when players lose out by drawing a game, they can't help themselves from copying the hand gestures of their opponent. The result is surprising because advantage is gained in the game by acting differently.

Usually when chance is the only factor, about a third of the games should end in a draw. But the experiments, conducted by psychologists at University College London, confirmed that more games end in a draw due to the subconscious mimicking.

The team asked volunteers to play two versions of the game: one with both participants blindfolded, and one with only one blindfolded. With both players blindfolded, the draw rate was 33.3 percent -- exactly as predicted by chance. But when only one was blindfolded, the draw rate was significantly higher at 36.3 percent.

Even when the participants were offered money if they won their matches, they sometimes still could not help but imitate their opponents hand shapes.

Richard Cook, of the UCL Department of Cognitive, Perceptual and Brain Science, and lead author of the study, said that imitation was hard-wired into the human brain.

"From the moment we're born, we are frequently exposed to situations where performing an action accurately predicts seeing the same action, or vice versa. Parents seemingly can't help but imitate the facial expressions of their newborns "“ smiling, sticking their tongues out and so on," he told the Telegraph.

"This experience causes the impulse to imitate to become so ingrained it is often subconscious, for example when one person starts tapping their foot in a waiting room it is not uncommon for the whole room to start tapping their feet without thinking," said Cook.

It was "well established" that imitative responses happened faster than controlled ones, so people were carrying them out without even being conscious of them. "The present finding confirms that imitation is often "Ëœautomatic' in the sense of being hard to stop," he said.

"Lots of people have shown before that this automatic imitation is automatic in the sense it's unconscious," said Cook.

"But no one has really ever addressed the extent to which it's hard to inhibit," he told BBC News.

When the team further tested the reaction times of the sighted players, their findings showed that when the blindfolded player played "rock" or "scissors" just slightly earlier, the sighted player was more likely to play the same.

Cook said that because of its universality among humans, automatic imitation was something like a conditioned response.

"Because you have so much experience of being imitated, of seeing the products of your own actions, it's difficult to resist - even when it's in your best interests," he explained.

Christian Keysers, head of the Social Brain Laboratory at the Netherlands Institute for Neurosciences, said that the work adds to past studies on the effects of automatic imitation, including a study in the journal Acta Psychological showing that hints of automatic imitation affected response times in a finger-moving task.

"The previous studies mainly focused on the fact that seeing someone else do something interferes with your own task and slows you down," Professor Keysers told BBC News. "What is new here - and quite exciting I think - is that the effect really goes towards tipping the balance to a different move altogether."

Automatic imitation is thought to be mediated by the human "Ëœmirror neuron system' -- a network of brain regions predominantly responsible for action execution, but which also respond to the passive observation of actions. This system is known to respond immediately to the sight of action, giving rise to an imitative bias almost instantaneously.

"It is well established that imitative responses are executed faster than non-imitative responses on controlled experimental tasks where reaction times average between 200-400 milliseconds. However, the present finding confirms that imitation is often 'automatic' in the sense of being hard to stop," Cook concluded.


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