Some say kisses are the ultimate expression of affection — even more intimate than sex.

Scientists have long seen kissing as a human universal, and spent lifetimes studying the evolutionary explanations for why swapping spit might unite us as a species. They say smooching helps us live longer, burn calories, pick the perfect mate or swap 80,000 healthy bacteria, even if it’s with someone who re-heats and eats their old McDonalds fries.

However, kissing is not the ultimate act of passion that every ending to a romantic comedy might have us believe. Quite the contrary, the majority of cultures around the world agree that locking lips is actually pretty nasty.

This insight comes from a recent study published in American Anthropologist, which examined 168 cultures over the course of the year, and found evidence of romantic or sexual kissing in only 46 percent of societies.

Cultures classified as a big fat no in the make-out department either 1) had never observed romantic kissing or considered it “disgusting,” or 2) had other types of kissing known to occur (ie. parent-child) but never of a sexual nature.

Although those societies are definitely bumping uglies, their idea of foreplay doesn’t follow strict traditional definitions. We’ve let Western culture dominate the way we think about human behavior, but these non-kissing cultures are another reminder of the sexual diversity we’re somehow surrounded with, yet so rarely see.

The researchers found that kissing is common among cultures in the Middle East, Asia, Europe and North America. In the Middle East, 10 out of 10 cultures studied see kissing as established custom. In Asia, 73 percent enjoy locking lips; in Europe, 70 percent; and in North America, a surprisingly small 55 percent.

However, in societies from Central and South America, Africa and Oceania, smooching is far from the norm. The researchers believe that the structure of these societies might explain why they reject tonsil-hockey as a romantic gesture.

“The more socially complex the culture, the higher frequency of romantic–sexual kissing,” the researchers write. Specifically, they focus on social stratification. Societies that rank categories of people in a hierarchy based on level of status, power and wealth are more likely to practice kissing in an erotic type of way.

This is welcome news, as kissing is a great equalizer. No exclusive giving or receiving, no exchange of power, just 50/50 sexual equality (and maybe a taste of last night’s french fries).