It looks like there’s a reason why Lassie was smarter than Old Yeller. (It’s called science.) Research to be published in Biology Letters, shows sex differences matter when it comes to how the brain works in animals as well as humans. (More on TIME.com: See a dozen bizarre animal friendships) Scientists at the University of Vienna

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Are Female Dogs Smarter Than Male Dogs? Battle of the Sexes Extends to the Animal Kingdom