Monkeys Intuit Shapes Much Like Humans Do

Monkeys apparently don't need a math class to get the gist of geometry. A new study in the Proceedings of the National Academy of Sciences finds that olive baboons and rhesus macaques not only recognize basic geometric relationships, they seem to process them in similar ways as humans do, reports Popular Science. "Monkeys, children, and adults seemed to think about geometric relationships in fundamentally the same way," study co-author Jessica Cantlon of Carnegie Mellon University says in a statement, calling those abilities "part of the basic architecture of the primate mind."

Researchers tested zoo primates at New York's Seneca Park Zoo using a touchscreen shape-matching game that lacked obvious visual cues like bold colors or major size differences—something Cantlon warns would trip up many people, too. The scientists then ran the same task with preschoolers, US adults, and almost 80 adults from Bolivia's Tsimane' people, who don't receive formal schooling. Across that spectrum, performance suggested humans start life with built-in spatial intuitions that schooling later refines, rather than creates from scratch.

Combined with ancient geometric markings on artifacts, the findings point to geometric reasoning as a deep evolutionary trait—one that, in at least one baboon named Kalamata, comes with marathon attention spans. That monkey "was the hardest working monkey that I've ever seen," notes study co-author Jialin Li. "He would come up to the screen and wait for me to turn the computer on, and then he'd just sit there for two to three hours just doing all kinds of mathematical tasks."