In the movie Fingernails (2023), scientists have developed a test that can determine whether a couple is truly in love. As a metaphorical commentary on the finger swiping involved in contemporary dating, the test involves pulling out a fingernail and putting it in a silly microwave-like device that informs whether one or both individuals are in love. The premise is fantastical, and few scientific details are provided, but the social and interpersonal dynamics around this “biomarker” of love got me thinking about the search for behavioral and psychiatric biomarkers generally.
