Rats beat humans by always betting on green
People lose because they cannot resist hunting for a pattern that is not there.
Veritasium · The Expert MythRats beat people at a simple guessing game by refusing to be clever.
The game has two buttons. The green one lights up 80% of the time and the red one lights up 20% of the time, in random order. Players have to press the button they think will light up next. Rats get a bit of food for a correct guess and a mild shock for a miss.
Rats quickly settle on pressing green every time. That guarantees an 80% success rate, the best possible score.
People usually press green too, but every so often they try to guess when red is due. Because there is no pattern to find, their score drops to 68 percent.
Humans hate settling for average, so they chase patterns even in randomness, and lose.
Questions people ask
Why is always picking green the best strategy?
Yes. The best you can do is match the most common outcome every time. If green appears 80% of the time at random, always choosing green gets you 80% correct. Any time you guess red, you will be wrong four times out of five on those guesses.
Do people do this in other situations?
This tendency is called probability matching. People tend to match their guesses to the observed frequencies, choosing green about 80% of the time and red about 20%, instead of always choosing the more likely option. Animals from rats to pigeons tend to maximize instead, and do better.