Study reveals monkeys believe in winning and losing streaks

A new study has revealed that monkeys also share humans' unfounded belief in winning and losing streaks.

According to the researchers, the penchant to see patterns that actually don't exist may be inherited, an evolutionary adaptation that may have provided our ancestors a selective advantage when foraging for food in the wild.

The researchers created three types of play, two with clear patterns (the correct answer tended to repeat on one side or to alternate from side to side) and a third in which the lucky pick was completely random. Where clear patterns existed, the three rhesus monkeys in the study quickly guessed the correct sequence. But in the random scenarios, the monkeys continued to make choices as if they expected a "streak". In other words, even when rewards were random, the monkeys favored one side.

The monkeys showed the hot-hand bias consistently over weeks of play and an average of 1,244 trials per condition and had lots and lots of opportunities to get over this bias, to learn and change, and yet they continued to show the same tendency.

The scientists said that the results also could provide nuance to our understanding of free will.