AILSA CHANG, HOST:
Squares, triangles, circles - these geometric shapes appear everywhere in art and architecture going back all through human history. Geometric regularity seems to be something that the human brain is primed to recognize. But what about the brains of other animals? Well, NPR's Nell Greenfieldboyce reports that scientists recently gave a geometry test to crows.
NELL GREENFIELDBOYCE, BYLINE: Crows are pretty smart. They can make simple tools. And at the University of Tubingen in Germany, there's a lab where crows learn to play computer games. It's the lab of cognitive scientist Andreas Nieder. He says the games are designed to tease out what crows know about math. In one study, for example, a computer screen showed crows a certain number of dots, and the crows had to count them by pecking.
ANDREAS NIEDER: They can see three dots and then produce three pecks and then press an enter key sort of in order to tell us that they're done with the counting sequence.
GREENFIELDBOYCE: It turns out the skills of counting crows rival those of toddlers. Recently, Nieder wondered what the crows knew about geometry. Could the crows distinguish regular shapes, like squares or parallelograms, from irregular quadrilaterals? So he had a couple crows learn a new game. The birds would see six shapes on the screen, and they'd have to pick the one shape that was different.
NIEDER: And initially, we presented some very obviously different figures - say, for instance, five moons and one flower.
GREENFIELDBOYCE: If the crows pecked on the flower, they'd get a treat, like yummy mealworms. Once the birds knew the drill - find the thing that's different - the researchers started testing them with geometric shapes, showing them, say, five perfect squares along with another four-sided figure that was just a little off.
NIEDER: And ask them whether they - with these quadrilaterals, they could still continue to find the outlier, even though the outlier was looking perceptually very similar to the other five regular shapes.
GREENFIELDBOYCE: Turns out the crows could. In the journal Science Advances, the researchers describe a series of tests showing that crows clearly had a sense of right angles, parallel lines, symmetry. And that's a big deal because Nieder says before this...
NIEDER: There was no single animal that demonstrated this capability of detecting geometric regularity.
GREENFIELDBOYCE: There was one recent study that looked to see if a nonhuman primate could do it - baboons - but no dice. Nieder says it's not really clear why the baboons couldn't. Maybe in other situations, they or other monkeys would be able to. But what's important is that clearly, humans' predilection for geometry didn't come out of nowhere. It's out there in the animal kingdom.
NIEDER: Because we have at least a crow. And again, I would never dare to say that this is the only species. It's just now opening up this field of investigation.
GREENFIELDBOYCE: The study impressed Mathias Sable-Meyer. He's a cognitive neuroscientist at the University of College London (ph) and is one of the researchers who previously tested baboons.
MATHIAS SABLE-MEYER: Baboons are so much closer to us, and we train them so much more.
GREENFIELDBOYCE: So he was surprised that, unlike baboons, crows were able to show off a sense of geometry.
SABLE-MEYER: I have to accept the result and think, you know, that's pretty cool. And then the question is, where does that even come from?
GREENFIELDBOYCE: He's looking forward to more studies in crows and other creatures. Unlike other mathematical abilities, like counting or understanding the concept of zero, intuition about geometry just hasn't been tested much in animals.
Nell Greenfieldboyce, NPR News.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.
