The question of whether you’re a cat or a dog person might not simply be a thing of preference. Denise Guastello, an associate professor of psychology at Carroll University in Wisconsin, believes that the preference stems from some of our underlying personality differences. “It makes sense that a dog person is going to be more lively, because they’re going to want to be out there, outside, talking to people, bringing their dog,” Guastello said. “Whereas if you’re more introverted and sensitive, maybe you’re more at home reading a book, and your cat doesn’t need to go outside for a walk.” It suggests that our environments, preferences, and personality traits are deeply intertwined. As a result, we are more likely to pick an animal that fits into our lifestyles.