It’s well established that holding the door open for someone who is more than a few feet behind you can lead to awkwardness. But according to a Purdue University study cited by The Guardian on Tuesday, holding the door for another guy, no matter how close behind you he is, is kind of a jerk move.

“Men who’d had the door opened for them reported lower confidence and self-esteem,” The Guardian reports, while also warning us against addressing a fellow man as “my friend,” “admiring his things,” “lending him a novel,” and “doing the extra touch when you shake hands.”

Somewhat bafflingly to us, the researchers also found that buying your buddy a drink can make him feel a little lacking in the testosterone department. Presumably, buying the whole round is okay. Just don’t hold the door open when you leave the bar.