You (probably) won\u2019t find a monkey in a geometry class, but it looks like our fellow primates can swing the basics.<\/p>\n
Just like people, monkeys seem to grasp the abstract qualities of geometric shapes, such as whether they are symmetrical, have parallel sides or contain right angles, according to a new study published on Monday in Proceedings of the National Academy of Sciences<\/a>. This ability allows the monkeys \u2014 and us \u2014 to understand when two shapes are the same, even when they\u2019ve been rotated or resized.<\/p>\n This finding challenges a long-held notion that humans\u2019 geometric abilities are part of what makes our brains one of a kind. \u201cOur hypothesis was that humans are not that unique,\u201d in possessing this mathematical understanding, said Jialin Li, a cognitive neuroscientist at Carnegie Mellon University and the lead author of the study.<\/p>\n In their experiment, Ms. Li and her colleagues decided to give monkeys (a total of eight rhesus macaques and olive baboons), preschoolers and adult humans with different education levels the same geometric task. That way, if humans truly had an innate advantage, it would show up when comparing the young children and the monkeys. And if the advantage was learned, it might show up when comparing the humans who had different levels of schooling.<\/p>\n It was a challenge to find a task simple enough that even preschool-aged children and monkeys could reasonably complete it, but the team eventually decided to have all the study participants do a matching task. All were shown a shape with a specific size and geometric form on a screen. Then they were asked to pick that same shape out of a group of others.<\/p>\n \u201cBy manipulating the similarity of the shapes, we were able to look at what kinds of rules they\u2019re using,\u201d said Jessica Cantlon, a cognitive neuroscientist at Carnegie Mellon University whose lab conducted the study.<\/p>\n For correct matches, the monkeys, preschoolers and adults received positive feedback: a treat, sticker or affirmation, respectively. But the mistakes, which were met with no reward, were just as important in order to understand what concepts were easy and difficult for the brain.<\/p>\n \u201cThe task certainly depends on a broad network of brain regions and circuits involved in visual and cognitive processing,\u201d said David Freedman, a neurobiologist at the University of Chicago who was not involved in the new research. Matching tasks rely on both basic visual cues \u2014 like a shape\u2019s edges and contours \u2014 and a higher-level understanding of shape identity and structure.<\/p>\n