The Dilemma: At a cocktail party, a nasty brute spills a drink on you. You'd like to compare his manners to those of a more primitive hominid. But which would be more insulting?

People You Can Impress: Anthropologists—they're just happy to talk to someone who's not a fossilized skeletal fragment.

The Quick Trick: Neanderthals are more primitive but stronger. Cro-Magnons are us.

The Explanation: Cognitively speaking, it's definitely more insulting to call someone a Neanderthal. But if you're talking musculature, they might just take it as a compliment. Neanderthals (Homo neanderthalensis) were discovered first in Germany's Neander Valley in 1856. They emerged between 100,000 and 200,000 years ago, give or take, in the early and middle Paleolithic era, and they used tools, albeit very simple ones. Often they resorted to using rocks (or flakes broken off of rocks by hitting them with other rocks), bones, and sticks. And they used fire, too! Neanderthals were more muscular than the later Homo sapiens, and their skulls were flatter, with broad noses and pronounced ridges on the forehead (which is why, to us, they look rather dim). They were also capable of speech, but recent physiological discoveries indicate that their voices were high pitched and nasal, not the baritone grunts we normally associate with cavemen. Despite their similarities to us, they were not—repeat, not—a step on the way to us. They were a dead-end offshoot of an earlier common ancestor, and they eventually lost out to their smarter, more advanced cousins: Cro-Magnons.

As for Cro-Magnons, they're pretty much just like us. They take their name from a cave in France where Louis Lartet found them in 1868. (Well, he found their skeletons. They had died a while before.) Unlike Neanderthals, Cro-Magnons are not a separate species from Homo sapiens. In fact, they're the earliest known European example of our species—living between 35,000 and 10,000 years ago—and are actually modern in every anatomical respect. They did, however, have somewhat broader faces, a bit more muscle, and a slightly larger brain. So how'd they utilize their larger noggins? Cro-Magnon man used tools, spoke and probably sang, made weapons, lived in huts, wove cloth, wore skins, made jewelry, used burial rituals, made cave paintings, and even came up with a calendar. Specimens have since been found outside Europe, including in the Middle East.

Amazingly, the two species actually overlapped in Europe for a few thousand years. So did they interbreed? While scientists allow that there were probably plenty of random matings and hookups, any long-term interbreeding is unlikely. And while there are many reasons for this, the simplest are that a) they were probably physically repulsive to each other, and b) they couldn't meaningfully communicate. And also c) beer wasn't invented yet.

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This story originally appeared in our book What's the Difference?