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You'll notice right away that choosing the correct side without counting the fish individually is pretty tough. This difficulty stems from the fact that humans can only assess relative quantities by snap judgment under certain conditions. Take away six fish from the right-hand side, for example, and this task becomes noticeably easier.
Previous studies have shown that other primates handle numerical exercises like this one about as well as we do — but now, new research has revealed that the fish in this image are just as capable of this kind of task as humans and chimps. Find out how, when it comes to approximation, a guppy's math sense is every bit as good as yours. More »
