Gambler’s fallacy tested on actual gamblers
The answer to the mystery was revealed when Xu and Harvey analysed the odds of the bets placed by gamblers in the middle of a streak, and the amount they staked. Gamblers who won tended to take their next bet on a safer odds than the bet they had just won, with the reverse true for people on losing streaks. This, the researchers suggest, is because they believed in the gambler’s fallacy and so expected their luck to turn. This had the paradoxical effect of creating luck for those who were already winning - because they then made bets they were more likely to win - and rubbing in the bad luck of those who were losing - because they made bets which they were less likely to win and so perpetuated their losing streak.