If you get the giggles hearing about a blue-footed booby or a tufted titmouse, science has your back. A study published in Behavior Research Methods ranked nearly 5,000 English words in terms of funniness, and immature people everywhere delight in the results.

The authors, Tomas Engelthaler and Thomas T. Hills, surveyed over 800 participants on their opinion of how funny English words were. The survey asked each participant to rank words from 1 (humorless) to 5 (humorous). The results were surprising and revealed some strange things about why certain words strike us as funny.

The funniest words were PG insults or names of body parts.

The 10 funniest words from the survey were: booty, tit, booby, hooter, nitwit, twit, waddle, tinkle, bebop, and egghead. Before you ask—yes, the survey asked participants to rank more obscene words. However, they didn’t rank as funny as the more innocuous words, like nutcase, plump, screwball, or buffoon.

Perhaps the high-ranking of these moderately naughty words comes from the methodology of the study. The survey specified that participants should rank words as funnier if they were “absurd, amusing, hilarious, playful, silly, whimsical, or laughable.” With that in mind, you can see why egghead would rank higher than an R-rated insult.

The obscurity of some of the words could also help explain why they ranked highly. We rarely hear the words hussy or floozy these days, so seeing those words out of the blue could boost their funniness.

There is another possibility of why these “naughty” words are funny—the benign violation theory (BVT).

A. Peter McGraw and Caleb Warren theorize that humor comes from benign violations of the way the world ought to be. For instance, most societies agree not to talk about private bodily functions or certain parts of the body. It’s especially uncouth to talk about these subjects in an obscene way.

However, something interesting occurs when we bring up these subjects in kid-friendly language. The combination of the violation and the silly phrasing strikes us as funny. Thus, someone who excuses himself from the dinner table to “take a whiz” may cause a few head shakes, but he’ll probably get a few laughs as well. Using a less whimsical phrase would likely cause more offense and less laughter.

The BVT would also explain why such tame insults rank higher than harsher ones. Calling someone an obscene name violates social norms, but not in a friendly way. Calling someone something nice is benign but makes no violation, so it isn’t funny.

When a person makes a violation and it’s benign, you end up with humor. Nimrod, twit, and egghead all rank highly on the humor scale for this reason.

Many of the funniest words simply sound funny.

The BVT may explain some humor, but there are words whose uncanny ability to tickle us is inexplicable. Jiggle, juju, and shindig don’t violate any norms, benignly or otherwise, but for some reason, they strike us as funny. The same goes for wiggle, noggin, oodles, and rumpus.

At the end of the day, humor is subjective. You don’t have to giggle at silly names for body parts, but please don’t think we’re buffoons, twits, or screwballs if we do.