Carlin Flora in Aeon:

New findings suggest that luck is not a phenomenon that appears exclusively in hindsight, like a hail storm on your wedding day. Nor is it an expression of our desire to see patterns where none exist, like a conviction that your yellow sweater is lucky. The concept of luck is not a myth.

Instead, the studies show, luck can be powered by past good or bad luck, personality and, in a meta-twist, even our own ideas and beliefs about luck itself. Lucky streaks are real, but they are the product of more than just blind fate. Our ideas about luck influence the way we behave in risky situations.

The team then dug deeper to reveal why these streaks were in fact real: it was the bettors’ own doing. As soon as they realised they were winning, they made safer bets, figuring their streaks could not last forever. In other words, they did not believe themselves to have hot hands that would stay hot. A different impulse drove gamblers who lost. Sure that lady luck was due for a visit, they fell for the gambler’s fallacy and made riskier bets. As a result, the winners kept winning (even if the amounts they won were small) and the losers kept losing. Risky bets are less likely to pay off than safe ones. The gamblers changed their behaviours because of their feelings about streaks, which in turn perpetuated those streaks.