Rock-paper-scissors may not be as random as you think: study

CTV science and technology expert Dan Riskin discusses a recent study suggesting that the results of rock-paper-scissors may not be random.

A recent study has found that the results of the popular decision-making game – rock-paper-scissors – may not be random.

Published in the Oxford Academic journal in September, the study found that the people exhibit behavioural biases in their decisions while playing the game.

Data from 62 participants who were matched into 31 pairs and played 480 rounds of a computerized version of the game was obtained for the study, using electroencephalography (EEG), a test that measures and records the electrical activity of a brain.

The researchers tried to measure the neural representations within the brains of both players through the results of the test.

They found that “rock” was chosen more than 50 per cent of the times, followed closely by “paper.” The least played move was “scissors.”

Their main finding was that the losing players showed stronger neural encoding of their previous outcomes – meaning they were more likely to keep losing, because they were influenced by their previous choices during the game.

CTV science and technology expert Dan Riskin told CTV Your Morning on Monday that the biggest finding from the study was that people don’t repeat as often as they should.

“Whenever you hit a tie, (in) the next round you want to play the hand that would lose to the one that you just saw,” Riskin explained.

In other words, play the move that would have made you lose the game in the previous round.

The study looked at how brain waves were synced when people worked together, or against each other, to find out how decisions were made when humans interacted with each other.

“Many participants were biased towards changing their response, regardless of the outcome of the previous game,” the study read.

Meanwhile, the study suggested that when humans wanted to display co-operation, their behaviour becomes more predictable, and the synchrony increases. But when they’re contending, unpredictability is “advantageous,” which leads to lower synchronization, it read.

“People actually avoid synchrony because they need to be unpredictable to each other, and that gives you an edge when you’re in competition,” Riskin said.

The human brain relies on past results to predict their future moves, despite proving to be unhelpful in some situations, the researchers found.

“Small differences in wins and losses in some pairs suggest that chance, not strategy, determined the winner, likely adding noise and obscuring potential group differences,” the study read.

However, Riskin added that being “random” is “very hard for humans.”

The best way to throw a wrench in a losing streak during a game of rock-paper-scissors is to employ randomness to your moves, the study stated. If someone is changing their moves each time they play, use the move that would lose to their previous play.