Subliminal messages—hidden phrases in TV programs, movies, and ads—probably won't make you run out and join the Navy, appreciate a band's music, or start smoking. That's because these sneaky suggestions don't really change consumer behavior, even though many people believe otherwise, according to Sci Show Psych.

We say "don't really" because subliminal messages can sway the already motivated, research shows. For example, a 2002 study of 81 college students found that parched subjects drank more water after being subliminally primed with words like "dry" and "thirsty." (Participants who weren't already thirsty drank less.) A follow-up experiment involving 35 undergrads yielded similar results, with dehydrated students selecting sports drinks described as "thirst-quenching" over "electrolyte-restoring" after being primed for thirst. Experiments like these won't work on, say, chocolate-loving movie audiences who are subliminally instructed by advertisers to purchase popcorn instead.

Learn more about how subliminal messaging affects (or doesn't affect) our decision-making, and why you likely won't encounter ads with under-the-radar suggestions on the regular.