While baboons can’t read, they can tell the difference between real English words and nonsensical ones, a new study reports.

“They are using information about letters and the relation between letters to perform the task without any kind of linguistic training,” said Jonathan Grainger, a psychologist at the French Center for National Research and at Aix-Marseille University in France who was the study’s first author.

Dr. Grainger and his colleagues worked with six baboons that were given free access to touch-screen computers, which displayed four-letter sequences. If a baboon tapped the screen when the sequence was a real word, it received a treat.