Most everyone has been in a situation where the person you're dating, or interviewing, or arguing with makes a comment and something just feels ... off.

Perhaps it's less about what they said explicitly and more about how they looked while they said it. As in, their gaze was freakishly fixed on your face or their left leg kept jiggling.

Scientists have spent decades trying to figure out what these nonverbal displays really mean.

And while sometimes they mean absolutely nothing, in other cases they can reveal a lot about what the person is thinking or feeling. Maybe they're super nervous, or maybe they're trying to trick you.

Below, we've rounded up 18 of the most useful scientific insights into the significance of body language, pulled from Psychology Today, research journals, and a few awesome books.

Keep in mind that context is really important — for example, you can interpret crossed arms to mean that someone's closed off, or that they're cold. Use your own judgment.

This is an update of an article originally posted by Drake Baer and Max Nisen.

The shoulder shrug is a universal signal of not knowing what's going on