We all grow up hearing the same rule: lying is bad. Simple enough, right? Just don’t say things that aren’t true.

Well… linguists would like to complicate that.

In this episode of Otherwords, Dr. Erica Brozovsky explores the surprising science behind deception. The discussion kicks off with a concept from the sci-fi novel The Three-Body Problem, which imagines aliens who literally cannot lie because every thought in their heads broadcasts like a radio signal. Imagine living like that. Your brain would basically be a public Twitter/X feed.

The video explains that deception exists all over nature. Stick insects disguise themselves as sticks, cuttlefish pretend to be female to fool rivals, and birds fake broken wings to distract predators. But these aren’t really lies, they’re instinct.

Humans, on the other hand, are masters of intentional deception. And here’s the thing: you don’t even need to say something false to lie. Leaving out key information, implying something misleading, or answering questions very carefully can do the trick. Lawyers have built entire careers on this.

The problem is that lying is mentally exhausting. You have to track the truth, your previous lies, what the other person knows, and what they think you know. No wonder so many people are terrible at it.