Even Monkeys Believe In Hot Streaks
Monkeys trained to play fixed video games made moves indicating that they expected certain patterns to occur. Erika Beras reports
By Erika Beras

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Rolling five straight sevens at the craps table. Sinking eight consecutive three-point basketball shots. Making the light at the intersection every day all week.
Such streaks are all easily within the bounds of statistical probability. But when they’re happening, people believe that they have what is often called the hot hand. Our brains are hardwired to find such patterns and meaning. And now researchers find that other primates also appear to believe in streaks.
Scientists created computer games that could be played by rhesus monkeys. Some of the games were programmed to show clear patterns—that is, they were fixed. But one game gave random results.
The monkeys played more than a thousand rounds, for rewards. They did well in the games with the obvious patterns. But in the random game, the monkeys made moves indicating that they nevertheless expected patterns to occur. The study is in the Journal of Experimental Psychology: Animal Learning and Cognition. [Tommy C. Blanchard, Adreas Wilke and Benjamin Y. Hayden, Hot-hand bias in rhesus monkeys]
Evolution clearly favors the ability to find patterns—foraging for food and noticing where bunches of fruits occur is a great survival tool. But believing in a hot hand, especially in casinos, can make monkeys out of all of us.
—Erika Beras
[The above text is a transcript of this podcast.]
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