The cartoon archetype of a drunk person is a disheveled mess, with droopy eyelids, an erratic gait, and bubbles coming off their head—for some reason. If only it were so easy to tell if someone’s blitzed out of their mind. If a cop pulls you over, they can only objectively determine intoxication on the roadside with a breathalyzer: In the lungs, ethanol is transferred from the blood into air, so the device can detect alcohol in your exhalation. Even then, one person at the US federal legal driving limit of .08 breath alcohol concentration (BrAC) might act perfectly normal, while another person would be trying unsuccessfully to fish a slice of pizza out of a gutter.
But scientists are working on what might be a new way to determine intoxication, by returning to a stereotypical characteristic of the drunk that’s actually true: that soused walk. No matter how well