Baboons and 4-letter words point to origins of reading
Monkey see, monkey decipher. A group of baboons has learned to discriminate real English words from non-words just by looking at them written down.
The findings suggest that some of the mental processing involved in reading evolved separately from the specialised language centres that are unique to human brains.
"It's not that baboons can read," says Michael Platt of Duke University in Durham, North Carolina, who was not involved in the study. The baboons' achievement is only the first step in reading a word. They did not match the written words to sounds, or understand what the words meant.
Jonathan Grainger and colleagues of the University of Aix-Marseille, France, trained six captive Guinea baboons (Papio papio) to look at letters on computer screens.
Sometimes the baboons were shown a real, four-letter English word, but on other trials they were shown a four-letter non-word. They had to press one of two buttons, depending on whether a word or non-word was shown, and were rewarded with food if they got it right.
After a month and a half, the baboons had learned dozens of words: one could reliably identify 308. That is an impressive feat of memory, but is not that surprising. Most complex animals can learn to categorise objects into two groups, such as "leaves" and "rocks", given enough training.
But Grainger's baboons went one further. After they had been practising for some time, they became much better at identifying real words that they had never seen before. That means they had learned the rules that determine which letter orderings form real words, and could apply these rules to distinguish them from unlikely letter orderings.
The findings suggest that the brain mechanisms human children use when they first learn to recognise written words are evolutionarily ancient, and were co-opted when written language came along, around 6000 years ago.