We are natural bookmakers. The ability to assess probabilities could be innate in all of us.
Children develop the ability to predict which of two simple events is more probable at around 5 to 6 years of age. But since this is also when most children begin school, it has been unclear whether this ability was innate or a result of the counting tasks common in early education.
To test this, Vittorio Girotto, a cognitive psychologist at the University IUAV of Venice, Italy, and his colleagues sought out rural Mayan villagers in Guatemala who'd had no formal education. Girotto's team gave 20 adult Maya three tests to gauge their intuition about probabilities. One test asked which of two containers they were more likely to draw a red token from: one with a higher proportion of red tokens, or one with a lower proportion but a higher total number of red tokens. Other tests probed their ability to modify their predictions based on new evidence, and to combine probabilities in more complex ways.
In every test, the Maya reliably chose the correct answer. Even Mayan children aged 7 to 9 years old – who had a little schooling, but much less life experience performed about equally well, and both groups did almost as well as a control group of Italian adults, Girotto found. "We wanted to show that this sense of chance exists, that it is universal, and that you do not need to be trained to evaluate uncertainty," says Girotto. "We have good evidence now that the human mind does possess this ability."
Peter Gordon, a psychologist at Columbia University in New York says that even illiterate villagers deal with probability every day when making decisions about which trees are likely to yield fruit or where the hunting is likely to be best. Even without formal education, Mayan intuition might therefore still be learned.
But if assessing probabilities does turn out to be innate within us, educators may eventually be able to take advantage of them in teaching formal lessons about probability, devising more intuitive ways of teaching probability that build on our natural understanding. "It could be the start of something interesting," says Brian Butterworth, a cognitive neuroscientist at University College London.
Journal reference: PNAS, DOI: 10.1073/pnas.1410583111
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