Science says that you can identify psychopaths by their frequent uses of the words “since,” “so that,” and “because” paired with repeated mentions of physical needs like food, money or sex… since they write like that so that they can satisfy their needs even if it means inflicting harm on others, because fuck ’em!

Researchers at Cornell and the University of British Columbia analyzed the writing of human lab animals and noted psychopathic killers’ letters describing their crimes.

Some practical uses for their discovery: Say you’re digging some cutie and their physical attractiveness is so blinding, it’s preventing you from picking up on their overtones of selfishness, detachment, and lack of remorse or empathy for other human beings. When you listen to them talk, you’re not hearing the scientifically suspicious pauses and “ums.” Troll their Facebook. Hold a thumb over their avatar if it helps. Count the “becauses.” Hesitate before giving them keys to your apartment. Thanks psychology!

Related: Conservatives Are Hard-Wired for Fear and Sexual Imagery Improves Memory.