Scientists love studying identical twins. When using one as the control and the other as the test subject, they’re able to compare the effects of anything down to the twins’ DNA. So it makes sense that Trident gum’s maker, Mondeléz International, would use identical twins to disprove the common idea that chewing gum is rude. At the end of it, they say, “They aren’t identical. The one chewing gum gives a better impression.”

The “experiment” takes place at the Museum of Contemporary Art of Buenos Aires, in Spain, and puts 481 people in a chair with two buttons. They’re asked questions about the twins, such as “Which one seems like he has more friends” and “Which one gets invited to more parties,” while the twins sit in front of them — one sits there chewing Beldent while the other sits stone-faced.

It’s a good promotional stunt for the food company, but, as one Reddit user points out, “The brain relies heavily on body language. While chewing gum, the facial expression is dynamic and the brain has a harder time associating that dynamic facial expression with a particular emotion. As such, the brain may give such dynamic expressions the benefit of the doubt. The neutral expression faces do give the brain something to latch onto, in terms of interpreting an emotional state. Thus, it may not be that gum chewers are viewed more favorably, but that neutral-faced people are viewed less favorably.”

The commenter is completely right, too. Multiple studies have shown that people who observe facial expressions unconsciously identify with them. Both a 2000 study and a 2002 study found that people’s facial muscles reacted to expressions, even when they were told not to move. “Despite the fact that exposure to happy and angry faces was unconscious, the subjects reacted with distinct facial muscle reactions that corresponded to the happy and angry stimulus faces.” Therefore, it’s probably safe to say that this whole promotion was one big trick.