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Ten Things We Still Don't Understand About Humans
ParticleGirl writes "New Scientist has an article examining 10 human features (bugs?) that we still don't understand, like blushing, laughing, and nose-picking. There are some interesting, speculative evolutionary explanations listed for each. '[Psychologist Robert R. Provine] thinks laughing began in our pre-human ancestors as a physiological response to tickling. Modern apes maintain the ancestral 'pant-pant' laugh when they are tickled during play, and this evolved into the human 'ha-ha.' Then, he argues, as our brains got bigger, laughter acquired a powerful social function — to bond people. Indeed, Robin Dunbar at the University of Oxford has found that laughing increases levels of endorphins, our body's natural opiates, which he believes helps to strengthen social relationships.'"
Does anyone else just immediately stop listening when they see words like 'meme'?
Perhaps 'meme' is a fnord.
Kurt Vonnegut sort of agrees (about the reduced defenses) : "Jokes can be noble. Laughs are exactly as honorable as tears. Laughter and tears are both responses to frustration and exhaustion, to the futility of thinking and striving anymore. I myself prefer to laugh, since there is less cleaning up to do afterward â" and since I can start thinking and striving again that much sooner."
Laughter is certainly not always pleasant, as anyone who's laughed to much will tell you. You know the laughter that borders on hysteria and sometimes ends in tears. It IS a cleansing experience though, your body's safety valve for letting out stored up emotion and frustration.
If all else fails, immortality can always be assured by spectacular error.
Personally I think the nose and the nasal passages are undergoing some of the fastest evolution of any part of the body right now. You see a huge variation in nose shape around the world, and I don't know about you but personally my nose is one of the most annoying parts of my body, not allowing enough air through and often getting clogged, sometimes running, sometimes bleeding for no reason, and getting boogers (there must be a technical term, please enlighten me). I often wonder if people with different-shaped noses have the same problems I do, or if these problems are solved in the nose designs of other races.
Damn forgot to mention, ofcourse there's the whole "mutual aid" as an evolutionary advantage thing. But that's a REALLY old idea, I mean 1890's old. People just ignore it though, doesn't fit in with the ideology and the travesty they've made of the whole "survival of the fittest" thing.
If all else fails, immortality can always be assured by spectacular error.
Laughter, art, pubic hair and kissing are the only things that stand out on the list as possibly unknown. Art is probably the most complex and "advanced" of all human behaviors so it will only have a highly complex answer. I have this feeling that laughter is not unique to humans and is probably based at some level on a physiological/neurological response to a number of mental states such as relief, happiness, perception of incongruity (irony), and a few others (for some people pain which is where we will probably have the best shot at figuring out that actual mechanisms...). At least in males and probably females this would probably be the product of the overlapping expression of two (maybe more) genes, one receptor that triggers localized hair growth when it receives a signal from another molecule (probably testosterone?), thus, when humans hit puberty and start developing secondary sexual features high concentrations of pubes form in the crotch because the signaling molecule is in such high abundance there (just a guess...). Kissing? Hell if I know, maybe a delaying tactic developed by females to see just how committed and patient a male was.
Nose picking? DUH??!!?? Ever seen a fly groom itself or a monkey in the mirror? The monkey always checks its teeth. No one likes boogers, they are irritating, thus, remove the irritant. Same as picking at scabs.
Puberty? Tons of animals have it, its just another stage in development which just so happens to involve major rewiring of their neural circuitry and reformatting of their bodies. Not surprisingly, they tend to get a bit testy during this phase.
Blushing? Vasodialation caused by a hormonal release triggered by embarrassment AKA a type of fear.
Altruism? Pretty good explanations out there based on group selection theories and group size + competition.
Supersition? Our brains continually look for causes by default and when they don't find an obvious one they will make the next best connection based on the associations available in the brain. Very hand if someone comes up with a single universal cause for everything (god anyone?).
Dreams. Ok maybe not very well understood experimentally, but lots of animals dream. Neurons have to keep firing or they loose their connections, at some point during the evolutionary process a state developed for neural networks at rest were they started to replay their most recently experiences and integrate them in to the structure of the brain. Basically dreams are the time when the brain does upkeep and integrates its most recent experiences and solidifies the most memorable ones. Probably where we do most of our associational learning.
(Full disclosure: NON EXPERT, but this is /. so you know that already)
...to incest, which is bad for the gene pool.
When our primate ancestors stopped leaving the cave as soon as they could and started staying home with their parents until later in life, what better way to avoid interbreeding between offspring and parents than to make teenagers hate/piss off their parents, and do whatever they could to impregnate/get impregnated by someone else?
That's nature saying: "Get away from these same-gene carriers. Get out, and get wild. Multiply now!". And when they do, that's positive feedback for the evolutionary push. Interbreeding would reduce the probability of survival of the group in the long term (and short term, if <disgusting attempt to joke about people locked in basements removed>).
I want to know why noses run (secrete clear liquid) when it's cold outside.
The cold is an irritant, and there's this one trick that mucus membranes can rely on to ward off irritants: excrete mighty mucus!
Have you ever been out in minus 30 or below weather? The first breath you take flash-freezes all the humidity in your nose, it feels really weird. A nice layer of mucus between your living cells and water crystallization is better than frost bite.
You can't take the sky from me...
You pointed out nicely what I was about to post. Here are the links I was going to add though:
http://www.etymonline.com/index.php?term=teenage
http://www.answers.com/topic/teenager
http://www.home-school.com/Articles/PlattTeenagers.html
As resource bases contract and the world goes back to a solar economy, expect the teenager to disappear.
I wouldn't agree on this though.
Teen and teen-age are a western 1st world invention - now in use globally.
Unless entire western... no... HUMAN civilization disappears COMPLETELY - the term and the stage of human development it describes will remain distinctive from childhood and adulthood.
And I am talking going back to hunter-gatherer stage long enough that current languages are changed and forgotten.
Even then, upper classes WILL continue to pamper their young long after they (the "rulers" and "thinkers" - not the kids) stop writing dictionaries and regulating language. Teenagers would continue to exist in tradition among the upper class even if no one remained who could remember the word any more.
The only way it may be replaced or removed from use (other than what I said above) is if it is further broken down to early and late teens.
Into something like earleens and lateens. Or prims and seconds. Or juniors and seniors.
But, for something like that to happen you would need a HUGE social difference to appear. Globally.
Like for example giving 15-16 year-olds a right to vote or something similar.
Just like teenagers first appeared when kids globally started being sent to school despite hitting puberty (instead of being sent to work in mines, fields etc.) - a new stage in the society would have to be created first.
Mit der Dummheit kämpfen Götter selbst vergebens
I think you will find that most human reactions that occur "when it's cold outside" exist to help people survive in extremely cold weather. Maintaining a body temperature of 98.6 degrees in anything from 30 to 110 degree environments is quite a feat.
The benefit of a runny nose is to loosen mucous and prevent respiratory infections. This is obviously more important for people with large noses adapted for cold weather and those who spend long periods of time in confined spaces, during a long winter for example.
"I assumed blithely that there were no elves out there in the darkness"
Kissing? Hell if I know, maybe a delaying tactic developed by females to see just how committed and patient a male was.
From a "psychology of language acquisition" course I took back in the early '70s:
Apes and (some?) monkeys have a social signal called "pout face": It consists of puckering/pursing the lips in the direction of another individual, and signals that the sender is attempting to be friendly. It looks very much like a human's extreme solicitation for the other individual to kiss the sender (though it is not).
Perhaps kissing in humans as early pair-bonding and sexual foreplay evolved from this "Hi! Be my friend?" signal of our primate ancestors?
Alternatively: Some herd herbivores, such as camels, do kiss - to share saliva containing necessary digestive bacteria with other members of the herd, in order to help each other build and maintain a healthy digestive tract. This is especially necessary for getting cultures established in the newborn, to enable digestion of forage and thus weaning. Perhaps kissing babies performs a similar function for humans. If so: Courtship behavior often contains elements of treating the potential partner as one would a child, to show the partner that you'd be a good parent. Thus kissing as courtship would follow from kissing as a good child-care action.
A third possibility: Some diseases have different outcomes depending on what tissue receives the initial infection. Example: Smallpox. Before "vaccination" (injection of the related "vaccinia" (cowpox) live virus, which doesn't generally kill people and confers cross-immunity) was developed, "innoculation" with live smallpox virus insured that the infection started in the skin (usually survivable) rather than the lungs (usually fatal). The mouth has a VERY active branch of the immune system, as a defense against food-borne pathogens. Perhaps, when one is starting to come down with some infections, giving the other members of the family their initial infection in the mouth, rather than risking it take root in the lungs, increases their chance of survival.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Sleeping.
Why do we have to spend somewhere between 4 to 10 hours at a time in a defenseless state? What is the evolutionary rational for this mode of behavior?
There was a really good story not too long about about a theory of why dreams evolved. Basically, it says that it's practice for real-life situations. I know, sometimes they're crazy, how is dreaming that you've managed to go to school in just your underwear practice for real life? Although you may never actually go to school in your underwear, you do experience the same sensations in real life--embarrassment, fear, love (and lust), terror, and so on--that you experience in these crazy dreams. They prepare you for the real life stuff that happens to you.
Sounds pretty reasonable to me.
I recently discovered a general list of unsolved problems, which I find fascinating. It's like a summary of the current limits of science and human knowledge and understanding.
TFA was ridiculous.
That is interesting.
My nostrils are nearly the exact same size as my fingertips.
Is this true for others as well?
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
Once, I'd been sick with (what I thought) was a head cold for like, two weeks. It seemed to be getting better only very slowly. Then one day, while I was sitting at the computer, I feel something shift deep in my nasal cavity. Suddenly, something back there dropped and was heading down my throat. I reflexively gagged, as if I could have thrown up had the offending mystery gone much farther down. It ended up in my mouth for a brief moment before I reflexively spat it on the (carpeted, sadly) floor.
It turned out to be a rather long plug of mucus, the middle hard, the outside rather gooey (nearly like that slime stuff they used to sell in tubs as toys). It was awful, awful stuff, and I was too creeped out by it to experiment much with it.
Regardless, almost immediately my cold symptoms lifted 90%, and I was pretty much fully recovered from the "cold" the next day.
I guess what happened was, one of my sinuses got clogged (and perhaps infected), and that's what was causing the symptoms. By happy chance, the plug managed to exit my sinus on its own, and then everything was better.
Wish I could have manually extracted it!
This is not universal. As i have already posted, here (Austria and its similar in the rest of eu) a 16 year has a lot of legal responsibilities and privileges as adults do. You can drink and go to pubs and clubs (till midnight but nobody checks). Recently the law was changed and now they can vote. But they can also get permanent criminal records from 14. If they do something stupid they get the full blow etc, parents are not blamed. Everyone *expects* them to be far more responsible that where i came from (NZ).
Also what the parents expect of their teens makes a big difference.
The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
You have the "Adults and Children" up at dawn. For numbers, let's say 6 AM. They stay up until just after sunset, say 9 - 10 PM. Then the young adults take their shift, and stay up until about 3 or 4 AM, when the ancient ones (who folded at sunset around 7.30 PM) get up.
WHY would this work? To keep the fire going and guard against predators.
The old folks get things rolling, Adults and kids get up later and organise the days events. By the time they're ready to roll, it's getting on toward mid-day and the young adults are finally up and moving to supply the horse power.
It makes sense from a neolithic point of view...
RS
Shoes for Industry. Shoes for the Dead.
I don't think it's a question of whether they're going through changes. Children go through massive changes throughout their childhood. People go through large physical and emotional changes in their 20s, and again in middle age. We're constantly changing.
The issue that the GP is talking about is that we invented the idea of adolescence-- that is, a state between childhood and adulthood-- in the past hundred years or so. Before that, you were a kid until you were an adult
Whether this is a good or bad concept is up for debate, but most people who think very much about it seem to agree that it's a bad thing. It puts people in a sort of void state of not being a child, but not being an adult; being held responsible, but not really being held responsible; having people expect you to do a lot, but being consistently treated as useless and unhelpful. It's confusing and frustrating, and yet we keep stretching the period out longer and longer (people are now often expected to continue acting like teenagers until they're 25 or 30).
The idea behind stretching it out seems to be that people aren't ready to be adults, and need a probationary period, but the probationary period never seems to be enough. However, you could definitely argue that the reason it's not enough is because it's not actually preparing them very well for being adults.
Because people are animals and animals will eat anything edible if they get nutrition out of it. Oxpeckers groom the animals of the african savanha eating dandruff and earwax (which I hear is the same stuff as snot in a different form) amoung other things. A cats digestion is inefficient and there is still enough protein left in the end result for some dogs to want to eat it. There's an evolutionary advantage to enjoying your food no matter how disgusting.