6 Human Quirks You Didn't Know Have Evolutionary Origins

6 Sticking Out Your Tongue When You Concentrate Is A Remnant From The First Language

Picture yourself concentrating really hard: A grim set to your jaw, eyes narrowed, sweat beading on your forehead, the tip of your tongue sticking out all cute and stupid, undoing all that serious jaw-setting stuff ... What's up with that?

Well, according to the gestural protolanguage theory, the tongue thing is a behavioral remnant from when humans first developed language. Going from frantic grunting to quoting Shakespeare would have been a rather large leap for our club-bearing ancestors to make. As such, the earliest languages basically consisted of playing charades -- that is, mimicking common acts such as hunting, eating, or bashing skulls in with your club when Tok Tok doesn't get that hand-to-mouth means "eating." Jesus Christ, Tok Tok, get your shit together.

Gradually, the accompanying grunts evolved into spoken language, but the wiring for gestural language remained deep within our brain stuffs. And it could also explain why kids, and even the occasional awkward adult, stick out their tongues when performing manual tasks.

Researchers tested this hypothesis by observing children performing various high-concentration tasks. The tongue-wagging got progressively more prevalent as the tasks became tougher, which suggests some sort of feedback loop between our brains and appendages, which in turn may go a long way toward explaining why you perform intricate hand-talk ballets even when you're on the phone.

Furthermore, the study revealed that kids tend to jab their tongues to the right, indicating that the action is controlled by the left hemisphere of the brain -- the same part that handles the bulk of language processing. So if you're one of the few who've retained this habit into adulthood, you can breathe a sigh of relief knowing that you are not, in fact, a drooling idiot. You're simply healthily in touch with your inner caveman.

5 Sighing Prevents Suffocation

You may not be able to do anything about that impossible deadline your boss assigned you or that cute girl in algebra class who will never acknowledge your existence, but you can sigh heavily about both. Which is as good as doing nothing, but more passive-aggressively dramatic. And yet, according to science, all that sighing serves a secondary, arguably more important function: making sure you don't slowly suffocate to death.

Your lungs contain scads of tiny air sacs called alveoli, which exchange carbon dioxide for oxygen, allowing you to continue doing your two favorite things: living and breathing. Thing is, they also tend to collapse over time. Luckily, we also have a built-in mechanism for preventing that: taking an extra-large gulp of air, also known as a sigh. This simple act pops those little bastards right back open and keeps you living, no matter how badly you wish you could die already.

That's also why sighing is associated with stress -- popping the alveoli back into fighting shape is accompanied by a feeling of relief, acting as a sort of "reset button" for both our mood and our respiratory function. We do it far more than we realize -- about every five minutes, on average. Hell, just reading this probably has you sighing constantly, a bit like contagious yawning. Hopefully, only half of those are in frustration at our terrible jokes.

4 You Talk Like That Because Of The Environment

Why does Spanish sound so sexy, while Swedish is fodder for Muppet mockery? The "acoustic adaptation" theory posits that a region's climate has a direct and profound effect on the languages that develop in that area. In essence, the evolution of a place's lingo is influenced by the landscape, temperatures, and even rainfall of the locale, all of which are factors determining which sounds will be used frequently and which won't. The reason is simple physics: Sound waves don't behave the same in the woods as they do in open fields, and they behave differently yet in snowy mountains.

For instance, consonants are easily distorted or lost altogether in a rainforest, making them the weakest link in a language evolving in such an environment. By the time you've figured out what "etch ou fo tha agua" means, you've been eaten by a jaguar. Conversely, the consonant-heavy Germanic languages, such as English, could develop quite nicely in the hills of Europe, where the acoustics are perfect for warning people about marauding Visigoths, who ironically are not easily visible.

Moreover, the climate may not only determine which types of sounds appear frequently in a language, but also the way those sounds are combined to form words. Tropical habitats are likely to produce languages with lots of open syllables -- think "aloha." Meanwhile, consonants at the ends of syllables don't perform as well in the heat, but have much better job prospects in colder venues with names like Deutschland. This phenomenon is even observable in birds: Species native to rainforests tend to use fewer consonant-like sounds, and vice versa. Of course, birds only ever really announce that they wanna bone a lot and right now, so their regional constraints are a bit more forgiving.

3 Shaking Your Head Originally Meant You Were Full

Next to throwing up the horns whenever somebody mentions Slayer, the most universally recognized human gesture is the head shake, which signifies a negative response. But what a strange way to communicate that. What logical relation could there possibly be between turning your head from side to side and denying a proffered Double Down?

That is in fact a pertinent example, because the prevailing theory on the origin of the head shake is food-related. Since babies don't have the whole "language" thing down yet, they simply turn their heads away from food when they're full. This simple denial of food mentally links the gesture to the concept of negation, and it's this relationship which survives into our adult lives, where it can serve many purposes, ranging from "not hungry" to "not right now" to "that is not my German porn, and I will not dignify your accusations with a verbal response."

2 Scowling Is Flexing (With Your Face)

Hey, we heard your mom's college nickname was Clappy McCondomTrap. You're a biological curiosity -- the first human conceived not by your father's sperm, but by his tears of regret. Your mom's vagina is like a Slip 'n' Slide, if a Slip 'n' Slide were bigger, floppier, and more prone to misuse.

Are you angry yet? Good!

Look at your face: You're scowling. Why are you doing that, aside from all of our needlessly personal insults about your mother? Researchers from the University of California at Santa Barbara and Griffith University in Australia set out to answer that. While science has long considered the "anger face" to be an ingrained facet of our basic biology, its origins are more enigmatic. So professors Aaron Sell, Leda Cosmides, and John Tooby set out to explain why the contraction of seven distinct muscle groups -- "lowered brow ... raised cheekbones (as in a snarl), lips thinned and pushed out, the mouth raised (as in defiance), the nose flared and the chin pushed out and up" -- is the universal human expression of anger. To do so, they isolated each component of the "anger face" and showed the resulting computer-generated faces to test subjects. And even when shown in isolation -- only the lowered brow or just the thinned lips, for instance -- subjects reported that the expressions made the depicted individual look physically stronger.

So there you have it: Each individual feature of your grumpy face has evolved specifically to make you look more badass. Well, not you. You look like a constipated baby. But other people look super tough.

1 We Call Our Parents "Mama" And "Dada" Because They're The Easiest "Words" To Say

Unless you've royally screwed up and your baby's first words are "I pwead the fifth," they were probably either "mama," or "dada." And oddly enough, those words sound very similar in every single language, all across the globe. American and European children usually go with "mama" and "papa," Chinese babies prefer "mama" and "baba," while Turkish kids go with "ana" and "baba." You're probably wondering how this is even possible. The answer, of course, is ancient aliens.

Actually, linguistics pioneer Roman Jakobson solved this peculiar phenomenon decades ago. He theorized that babies aren't simply hopelessly unoriginal, but rather desperately trying to get a grip on this whole "articulation" thing. This process mainly involves a buttload of gibberish, but Jakobson discovered that there's a technical side to it as well. Speech sounds are acquired in a specific order, based on their complexity.

This means that, while enunciations which require all sorts of fancy vocal acrobatics, like r and w, are learned relatively late, mmm is the result of an infant seeing what happens when they fire off their vocal cords while keeping their trap shut. Doing the same thing with their mouth wide open results in ah. Getting from m to p requires only the addition of a small puff of air.

So because babies are lazy little idiots, the first sounds they begin repeating are "mama" and "papa," and emotional parents adopt those as their loving nicknames. Also because they're lazy little idiots. We're all lazy little idiots, when you get right down to it.

When he's not busy keeping from going extinct, Guidodo is on Facebook. Bayfman writes about science at night and teaches it in the day. You can email him here.

For more questions brainiacs have found the answers to, check out 8 Simple Questions You Won't Believe Science Can't Answer and 5 Stupid Questions You Won't Believe Scientists Answered.

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