A recent study published in the Journal of Experimental Psychology suggests that when people are holding a gun, they’re less capable of evaluating a threat than they would be if they didn’t have a weapon in their own hands. Jessica Witt, a psychologist at Colorado State University, asked volunteers to hold either a plastic gun or a neutral object (such as a ball) as they reacted to pictures flashed on a screen. The photos depicted people holding various objects — sometimes a gun, sometimes a shoe, a soda can or a cellphone. While holding a gun, volunteers were more likely to misidentify the object in the photo as a gun. (Likewise, if you’re holding a shoe, you’re more likely to think the guy in the photo is holding a shoe — but that mistake isn’t likely to end in tragedy.)