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Ten Things We Still Don't Understand About Humans 397

Posted by Soulskill
from the why-do-they-like-will-ferrell-movies dept.
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.'"
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Ten Things We Still Don't Understand About Humans

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  • Nose picking? (Score:5, Insightful)

    by 18_Rabbit (663482) on Friday August 07, 2009 @07:03PM (#28992307)
    What's not to understand? It clears the nose!
    • Re:Nose picking? (Score:5, Insightful)

      by Kokuyo (549451) on Friday August 07, 2009 @07:06PM (#28992321) Journal

      And is so much less uncomfortable than blowing your nose.

    • by Anonymous Coward on Friday August 07, 2009 @07:12PM (#28992375)

      And let's not forget how much fun it is. Not to mention how it drives the ladies wild.

    • by Anonymous Coward on Friday August 07, 2009 @07:17PM (#28992415)

      No, we do it because it tastes great

    • by PitaBred (632671) <(slashdot) (at) (pitabred.dyndns.org)> on Friday August 07, 2009 @07:25PM (#28992473) Homepage
      Aye. And it happens in children who are still not coordinated enough to figure out HOW to blow their nose. I'd love to get some grant money to study that...
      • Re: (Score:3, Funny)

        by Anonymous Coward
        If you claim that children who pick their noses contributes to global warming somehow, you will get all of the funding you want.
    • Re: (Score:2, Informative)

      by Anonymous Coward

      That's exactly what it is for. As mentioned above, even kids do it instinctively.

      The mucus in the nose protects the soft tissue and captures lots of bacteria and other germs. That stuff needs cleaned out every once in a while and blowing your nose can not get all that encrusted stuff out. You want rotting bacteria in your nose?

    • Re: (Score:3, Interesting)

      by Anonymous Coward

      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

    • by YrWrstNtmr (564987) on Friday August 07, 2009 @07:54PM (#28992713)
      Obligatory:
      Why do gorillas have such big nostrils?

      Because they have big fingers.
      • Re: (Score:3, Interesting)

        by X0563511 (793323)

        That is interesting.

        My nostrils are nearly the exact same size as my fingertips.

        Is this true for others as well?

    • Re:Nose picking? (Score:5, Informative)

      by Ozan (176854) on Friday August 07, 2009 @08:39PM (#28992959) Homepage

      I think the author equates nose picking with eating one's boogers, Mucophagy [wikipedia.org]. I would really like to know why people do THAT.

      As for nose-picking itself, since humans are dry-nosed primates, drying of mucus in the nose is natural and cleaning it out is as well.

      • Re: (Score:3, Insightful)

        by ozbird (127571)

        I think the author equates nose picking with eating one's boogers, Mucophagy. I would really like to know why people do THAT.

        Snort or pick, it's still the same booger.

        • Re: (Score:3, Funny)

          by lxs (131946)

          But you're missing out on a taste sensation and hours of fun.

    • Re: (Score:2, Insightful)

      This has to be true. Think about it - how did people clear their noses before facial wipes of any kind (handkerchief, tissue, anything) was invented? There seems to be no more natural way to go about it than just to pick it.

    • Re: (Score:3, Insightful)

      by skeeto (1138903)
      And isn't that such a great feeling of accomplishment when you pull out a nice big dry one? When you feel it peel away from the inside of the nose. I almost want to save them to look back on.
  • Missed one: (Score:5, Funny)

    by ninjapiratemonkey (968710) on Friday August 07, 2009 @07:07PM (#28992337)
    Women.
    • by joocemann (1273720) on Friday August 07, 2009 @07:17PM (#28992409)

      It has already been understood. Women are da debbil, like that foosball.

    • You should be glad there aren't any members of the fairer sex on Slashdot. You'd get your ass kicked.
    • Re:Missed one: (Score:5, Insightful)

      by Hurricane78 (562437) <deleted@@@slashdot...org> on Friday August 07, 2009 @08:26PM (#28992881)

      You don't. I do. In fact I changed from your point of view to being able to not only understand how women think but sometimes even play on their motivations like on a piano. Nice side effect: Works on men too! :) But of course, any unfair manipulation is completely out of question. Analog to "white hat hacking".

      But for you I have one single rule that you have to burn into your brain like your life would depend on it:
      It's not important what you say, but how you say it. Or more general, how it feels.

      This works while flirting, in every day communication, when arguing, when she asks if she looks fat, in creating a situation that will make her hot, etc, etc, etc.
      You can walk up to a girl, and literally say the biggest crap. If it creates the right feeling in her, it will work.
      That's why pickup lines are completely use- and pointless.

      Politicians and especially advertisers are professionals in this too. Because it works on the more "basic" emotional brain. (Which really is not "simpler" than logic, but just another kind of intelligence.)

      Never forgetting that single thing will help you more than any stupid relationship-help book. (Ok, I guess most of these include this nowadays.)

      • Re:Missed one: (Score:5, Insightful)

        by Hurricane78 (562437) <deleted@@@slashdot...org> on Friday August 07, 2009 @08:29PM (#28992901)

        Oh, I forgot: Of course I meant "how it feels for her"! Which means you have to listen to your emotional brain. Something that goes a bit against the stereotype of the cool western male, but in the end will make you a more manly man. (Protip: You still don't have to actually show all of those emotions. ^^)

        • Re:Missed one: (Score:4, Insightful)

          by Anonymous Coward on Friday August 07, 2009 @08:45PM (#28992999)

          I don't know, the level of unethical manipulation, objectivization, self-involvement, narcissism, and sexism in your theory seems perfectly consistent with the "stereotype of the cool western male."

          But you're right about not needing relationship-help books. They also just slap together half-assed, pseudo-psychology and painfully obvious observations on rhetoric.

          It's going to be painful, when you realize just how many women see right through your pose.

      • by Sciros (986030) on Friday August 07, 2009 @11:52PM (#28993869) Journal

        You can walk up to a girl, and literally say the biggest crap. If it creates the right feeling in her, it will work.

        I disagree, I walked up to a girl, and indeed literally said "the biggest crap," and it didn't work.

  • by Charles Dodgeson (248492) <jeffrey@goldmark.org> on Friday August 07, 2009 @07:12PM (#28992377) Homepage Journal

    ... the New Sensationalist [newscientist.com] seriously as a science magazine.

    (Fine, mod this flamebait. I've got Karma to burn and I really dislike that rag.)

    • by radtea (464814) on Friday August 07, 2009 @07:23PM (#28992451)

      ... the New Sensationalist [newscientist.com] seriously as a science magazine.

      Yeah, particularly as the article uses the outmoded term "altruism" for helping behaviour, and for some reason says, "most people say it doesn't make any evolutionary sense." I guess by "most people" they mean "most people who know nothing about the extensive and sound work on kin-selection and the evolutionary advantages of being a member of a group that engages in helping behaviour that has taken place in the past fifty years."

      Seriously, helping behaviour hasn't been an issue for a couple of decades, and only then amongst the innumerate hangers-on from an earlier era. No one who knows anything about modern evolutionary thinking believes it is an issue today, which pretty much means, "New Sensationalist chooses ignorant ass to make up plausible bullshit to sell magazines to ignorant people under the guise of science."

      • I agree with you, and more as they mention Art :

        Sexual display, learning tool or form of social glue? Art still refuses to be pinned down

        WTF? How about a way of expression?? It all starts when you have something in your head and there is no other way to communicate it...

    • by Cyberax (705495) on Friday August 07, 2009 @07:29PM (#28992519)

      Parent is not a flaimbait. NewScientist is definitely "new stupidist" in this article.

      For example, it's clear that altruism is generally good for the community (even though it might be detrimental to an individual), thus it makes perfect sense that we've evolved it. Same for blushing.

      Etc.

  • Good thing psychology figured out the rest of the puzzle, huh?!
  • Quick... (Score:4, Funny)

    by joocemann (1273720) on Friday August 07, 2009 @07:15PM (#28992393)

    ... smell my finger!

    (explain that one)

  • Memes (Score:4, Informative)

    by gmuslera (3436) on Friday August 07, 2009 @07:16PM (#28992405) Homepage Journal
    Memes [ted.com] could explain some of them. Some could be pure cultural (i.e. kissing, superstition, altruism) and others could had helped that we evolved this way (your odds of mating could had been increased if you had the ability to do some of those things).
  • Teenagers? (Score:4, Insightful)

    by russotto (537200) on Friday August 07, 2009 @07:18PM (#28992427) Journal

    Teenagers are not a biological issue at all, but a societal one. And one pretty easy to understand. Actually allow a smooth transition between childhood and adulthood, rather than making laws to restrict and "protect" teens until they hit that magic age of 18 or 21 or whatever, and while the problems won't go away, they'll become no worse than those of other young primates.

    • Re:Teenagers? (Score:5, Insightful)

      by Ralph Spoilsport (673134) on Friday August 07, 2009 @07:26PM (#28992487) Journal
      Right and wrong. Teenagers are an invention. It used to be that you went from late childhood (13 - 14) into adulthood. There's a reason why many people had little more than an 8th grade education - after that you were expected to join the world of work. Alexander the Great had pounded much of the world into submission by the time he was 20. "Teenagers" as we understand them are a product of post WW2 western culture as a market for commodity capitalism in the face of expanding resource bases. As resource bases contract and the world goes back to a solar economy, expect the teenager to disappear.
      • Re:Teenagers? (Score:5, Informative)

        by Anonymous Coward on Friday August 07, 2009 @07:45PM (#28992655)
        The Underground History of American Education is relevent here, if you're interested in one former teacher's account of how forced schooling came to be in the U.S. and where the new concept of "adolescence" came from. Highly depressing; I thoroughly recommend it. It's free to read online. (Not affiliated with it in any way, I just happened to have read it recently.)

        link [johntaylorgatto.com]
      • by c6gunner (950153)

        There's a reason why many people had little more than an 8th grade education - after that you were expected to join the world of work. .... As resource bases contract and the world goes back to a solar economy, expect the teenager to disappear.

        Wow ... so what you're saying is that Africa and the Middle East are actually progressive! Damn. We westerners are so ignorant ....

      • Re:Teenagers? (Score:5, Insightful)

        by Rozine (1345911) on Friday August 07, 2009 @08:09PM (#28992797)
        Just because society expected teenagers to work in the past doesn't mean that there aren't significant mental (physical brain) changes going on during that timeframe.

        And resources contracting back to a "solar economy"? Turn in your geek card - geeks believe in the power of technology to improve lives. There's no reason to expect that that won't continue.
      • by rm999 (775449)

        "Teenager" actually correlates with puberty pretty well. During puberty, people are drenched with abnormally high levels of various hormones which changes their behavior pretty drastically.

        A society that depends on 15 years olds in any serious manner is screwed.

      • Thank you! (Score:3, Interesting)

        by denzacar (181829)

        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 [etymonline.com]
        http://www.answers.com/topic/teenager [answers.com]
        http://www.home-school.com/Articles/PlattTeenagers.html [home-school.com]

        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 a

        • Re: (Score:3, Informative)

          In the country I live in, 16 year olds can vote, drink and go clubbing. They can get permanent criminal records and can leave school or whatever. The schools don't need to notify the parents of squat and they can even write there own "absentee" notes for school if they choose to attend.

          But they are still teenagers. Most still need parents to pay rent etc. So they are "dependents".

          My Grandfather left school (after the war) at 14, and was living on his own at 16 and married at 18. His wife was 16.

          Thi
      • Re:Teenagers? (Score:4, Insightful)

        by fermion (181285) on Friday August 07, 2009 @08:33PM (#28992933) Homepage Journal
        I agree. It is hard to say how what we call teenagers fit into the evolutionary system, I believe that the teen years, as depicted in the late and generation defining John Hughes films are more a reflection of having so much excess production that we not only need to insure that our children do not produce, but are also massive consumers. This is a recent phenomena, and a new state of adolescence.

        Evolutionary, we have a biology in which, I am told by people who seem to know, that a 15-17 year old girl is almost perfectly situation to bear offspring. The can carry them without the problems of later year, and often can deliver them without the difficulty of later years. Also the Circadian rhythm seems to change in a teen, allowing teens to sleep later, and in smaller chunks, as one might benefit one who had a child that needed to fed every couple hours. It is strange.

        This of course is one issue we have with teens. On one hand we want to treat them children, which they are not. On the other hand, we won't give them a responsibility, which they need. We still have high schools starting at the same time as the elementary schools, a pretty silly thing to do, many adults, if they have a choice, go to work between 8 and 9. Many young people, if they have choice, work the night shift. In this way, adolescence is truly screwed up because the teen is still controlled by the assumptions of the adults, while having legitimate needs that are given no reasonable outlet.

        • Re:Teenagers? (Score:4, Interesting)

          by Ralph Spoilsport (673134) on Saturday August 08, 2009 @07:04AM (#28995205) Journal
          agreed. What is also interesting is how circadian rhythms by age group match up.

          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

      • Re:Teenagers? (Score:5, Insightful)

        by CharlyFoxtrot (1607527) on Friday August 07, 2009 @08:46PM (#28993005)
        That's also why the world used to be a much more brutal place. Teenagers and their hormones and persecution and superiority complexes and need to prove themselves need to be contained until they mature a bit. Alexander the great sounds cool until you realize it was a guy with a god-complex (literally) running around with a private army slaughtering people everywhere he went to prove he was bigger and better than his daddy Philip.
    • Re:Teenagers? (Score:4, Insightful)

      by tacarat (696339) on Friday August 07, 2009 @07:33PM (#28992549) Journal
      Can it be argued that the some of the problems with teens is that they're treated as kids longer than is healthy? Folks used to be "adults" much sooner. Maybe it's Darwin award fodder, but if an adult makes a stupid mistake, they're morons and treated accordingly. If a child does it, they're "just kids" who couldn't have known better. If a teen does it then they're sort of in the middle, dumb, but not responsible. The coddling that some parents throw into the mix does nothing but protect or encourage some behavior.

      So yes, kids should be allowed to start drinking, swearing, fighting, fucking, smoking, shooting, PAYING THEIR OWN WAY and whatever else sooner in life than when they're allowed to now.

      /rant off
      /goto parent's basement of neverending virginity
      • Re: (Score:3, Interesting)

        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 (
  • ... as any fule know, is associated with a reduced defence mechanism and is therefore a sign of insanity.

    Simon (pulling some strings)
    • Re:Laughter... (Score:5, Interesting)

      by CharlyFoxtrot (1607527) on Friday August 07, 2009 @07:38PM (#28992601)

      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.

      • Re: (Score:3, Funny)

        by zobier (585066)

        I myself prefer to laugh, since there is less cleaning up to do afterward

        Unless your drink ends up on your monitor and keyboard.

  • by SanityInAnarchy (655584) <ninja@slaphack.com> on Friday August 07, 2009 @07:34PM (#28992559) Journal

    Example: Altruism.

    It actually seems pretty obvious -- a community which was altruistic would, in the long run, have a higher chance of survival than a community which wasn't.

    Another example: Superstition. I love this bit:

    Religion offers another possible evolutionary benefit of superstition.

    So... how is religion not superstition? Now you've got two mysteries, instead of one. And the same explanation still holds:

    Our ancestors would not have lasted long if they had assumed that a rustle in the grass was caused by wind when there was even a small chance it was a lion. And it is worth making false-positive mistakes to get these relationships right.

    Basically, religion and other superstitions are maladaptions of our ability to recognize patterns -- and an acceptable alternative to missing some pattern. Better to be paranoid than to be gullible -- better to be afraid of the tiger that isn't there than to be eaten by the tiger who is.

    I suppose these aren't proven, but I do find this pretty weak, even for a "top 10" list. It's not "mysteries" so much as "cases which are not yet airtight".

    • Re: (Score:2, Insightful)

      by jimshatt (1002452)

      So... how is religion not superstition?

      You read it wrong. TFA doesn't state that religion isn't superstition. It states that religion offers a benefit of superstition (the words are interchangeable a bit), namely promoting cohesion. This cohesion is a specific effect of religion and not of superstition, though the cause of both is the same because religion is a subclass of superstition.

    • Better to be paranoid than to be gullible -- better to be afraid of the tiger that isn't there than to be eaten by the tiger who is.

      Religion gets the gullible paranoid about an invisible, all seeing judgmental sky tiger.

      • Re: (Score:2, Insightful)

        You hold the same view on gambling as Descartes

        Do you mean Pascal [wikipedia.org] maybe ? Come on, the guy had a programming language named after him and everything.

        • You hold the same view on gambling as Descartes

          Do you mean Pascal [wikipedia.org] maybe ? Come on, the guy had a programming language named after him and everything.

          DOH! Descarte was the guy with the pineal gland problem, not the gambling problem :-|

    • Re: (Score:3, Insightful)

      by bjourne (1034822)

      Example: Altruism. It actually seems pretty obvious -- a community which was altruistic would, in the long run, have a higher chance of survival than a community which wasn't.

      But it isn't obvious. Ask yourself this, what is the best way for an individual to live in an altruistic society? Answer: to be a selfish asshole that takes advantage of all the altruistic suckers. That tension between what is best for an individual and the common good creates many paradoxical situations and is much more involved than what you seem to think.

      • by Ginger Unicorn (952287) on Saturday August 08, 2009 @05:58AM (#28995043)

        Being the asshole gets you a Pyhrric "victory" in the short term, but being the generous, helpful guy makes your life so much easier in the medium-long term. When the chips are down everyone rallies round to help you. People are also prepared to trust you in ways the asshole couldn't even imagine. People just give you stuff.

        Altruism begets altruism. Especially if you genuinely help people out of empathy/compassion rather than expecting something in return. (Most) People can tell when they're being manipulated. I know it's corny but helping people out really is it's own reward. Making people happy is a real buzz. Then you usually get another reward later from their gratitude. Talk about having your cake and eating it. Altruism dumps all over selfishness from a great height. Assholes don't know what they're missing.

    • by fermion (181285)
      Basically, religion and other superstitions are maladaptions of our ability to recognize patterns -- and an acceptable alternative to missing some pattern.

      There is no mal here. It is a simple matter of doing the best we can with limited data. At some point we as a people realized that every year there was less time of sunlight. We danced in hopes that the sun would not go away completely. The pattern recognition of the time determined pretty accurately the time of least sun, and set the dances then.

    • by Hurricane78 (562437) <deleted@@@slashdot...org> on Friday August 07, 2009 @08:52PM (#28993047)

      That's for old "nature" religions.

      Nowadays religion is basically two things:

      First a god is one way to cope with the fact, that we never can know where it all comes from. (The big bang and there being no time before it, is another more realistic one.) Of course they are all by definition unable to answer that question. But better than to get crazy, right?

      Second, the "get crazy" part: If you ever read something about what we used to call neurosis or schizophrenia: It is basically the "art" of twisting the world so it's OK to you, even when it's not. You for example state, that it was OK that you got raped, because you really did bad things to your father when you were young. And then go to do way too much good, to make up for it, afterwards. Or you run onto the highway because you think you can control the world. And then when you get hit, you later insist that you wanted it that way.

      Religion basically is a light form of schizophrenia. Which is bad and good. (In psychology, if something is a disease, depends on your/their view of "bad".)
      It basically helps people cope with bad lives, horrible things, wars, poverty, and the everyday frustration. They can blame it on a higher power, or on their own fault to live by the rules of that power. So while I am far from being religious, I can totally understand people who are, and their needs for it. It's a useful tool for a desperate situation.

      Where it gets bad, is when people want to profit from those people, by acting as if they were a mediator between them and their higher power. While essentially taking over their will and life. It's the biggest and one of the most evil scams -- off the backs of them.
      But hey, people strive for the reproduction of their genes, and of their ideas. It's called evolution. And mother nature is really a bitch.

  • by lalena (1221394) on Friday August 07, 2009 @07:49PM (#28992689) Homepage
    We've all heard the joke about how to get on the front page of Digg.
    Your article title should be "Top X {Reasons|Ways|Games...] To [Pick Up Girls|Make your own Fusion Reactor...]"
    Yesterday on /. it was an article on 10 failed mouse designs. Today it is 10 things we don't know about the human body.
  • Wow. (Score:4, Insightful)

    by Hubbell (850646) <.moc.evil. .ta. .iillebbuhnairb.> on Friday August 07, 2009 @07:52PM (#28992701)
    "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."

    Pretty sure this has been common knowledge for years/decades.
    • by hedwards (940851)
      It's more than that, humor is more than that, it's a way of maintaining status, either by ridiculing enemies or disarming them. There's a reason why we're so much more inclined to like dirty jokes or ones that make fun of people.
  • Some Seem Obvious (Score:4, Informative)

    by BinaryX01 (1609025) on Friday August 07, 2009 @07:57PM (#28992729)
    Some of these seem obvious, I am not a researcher or professor not am I involved with any sort of grant so I could be completely wrong but... Blushing - When we become excited or anxious blood rushes faster to the face that it is pumped away so the increased oxygenated blood causes the reddish tint, seems like this one is more of a why does our heart rate increase when we are excited or anxious? Pubic hair, we have hair around every part of the body that has more sensitive skin, head, genitals, inside of the nose, etc... Most of us don't have hair on the palms of our hands (you know who you are you unclean slashdotters) because that would interfere with tactile sensation needed for more dexterous tasks Teenagers, apes don't have someone constantly trying to sell them a look or mood. Teenagers don't invent fashions and trends marketers do. Then a popular teenager decides that what the marketer said about it being cool must be true and their peers all wanting to be cool too follow. I am pretty sure my grandmother was not "emo". Again it seems like the question here is why do humans feel the need to follow the crowd. Superstition - Somewhere along the way someone had a bad experience that they linked with another event (most likely coincidental) and they shared that information, and just as stories are retold superstition is passed along as well. There have also been some early studies showing that belief in superstitions may be a mild form of OCD. Nose Picking, if your nose is clogged up you pick it to open nasal passages. Like any other behavior this can become habitual to the point of it happening unconsciously at inappropriate times.
    • by reub2000 (705806)
      If the genitals need protection against chaffing, then why does the hair not develop until adolescence? Me thinks it's a marker of maturity, leftover from the days when humans created offspring at much younger ages.
    • Dreams explained (Score:4, Interesting)

      by KingSkippus (799657) * on Friday August 07, 2009 @10:30PM (#28993519) Homepage Journal

      There was a really good story [slashdot.org] 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.

  • by hyperion2010 (1587241) on Friday August 07, 2009 @08:01PM (#28992751)

    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)

    • 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 (thou

    • Re: (Score:3, Informative)

      by ParticleGirl (197721)

      The currently popular theory of kissing's adaptive nature holds that [bbc.co.uk] kissing is a way to exchange (biochemical) information about hormone levels and immune system types, and also promotes emotional attachment towards pair bonding.

  • by jsveiga (465473) on Friday August 07, 2009 @08:13PM (#28992819)

    ...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>).

    • Re: (Score:2, Insightful)

      by mldi (1598123)

      ...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>).

      Wow.

      I've never read such an insane "scientific" explanation for something as simple as a pool of hormones on a developing brain. That much going on will affect anybody.

      How far out do you think these cave dwellers actually ventured?

      Also, do you suppose in an earlier time when every able body was so important to the survival of the group, that "teens" would act out the way they do now?

      I would say it isn't an evolutionary response so much as just simple development. You're reading too much into it.

    • by AnyoneEB (574727) on Friday August 07, 2009 @10:20PM (#28993461)

      The main evolutionary reaction to incest is the Westermarck effect [wikipedia.org], which basically means that people usually are not sexually attracted to anyone they spent a significant amount of time around during the first six years of their life. As that usually includes their parents and siblings, it greatly discourages incest.

      There are other posts on this thread suggesting that teenage rebellion only occurs in some cultures, so biological evolution does not explain it, although you could perhaps argue that cultural evolution does... but I am not really sure how that would work.

  • Still haven't heard a reasonable explanation on that one.
  • by schweini (607711) on Friday August 07, 2009 @10:36PM (#28993549)
    I recently discovered a general list of unsolved problems [wikipedia.org], which I find fascinating. It's like a summary of the current limits of science and human knowledge and understanding.
    TFA was ridiculous.
  • by Repossessed (1117929) on Saturday August 08, 2009 @03:35AM (#28994641)

    Laughter increases the feeling of mirth in people who hear it.

    Mirth itself is harder to explain, but it appears to serve a number of purposes, from a defense mechanism against hopelessness to stress relief to social reinforcement (teasing, mocking).

  • Nosepicking (Score:4, Funny)

    by petrus4 (213815) on Saturday August 08, 2009 @07:40AM (#28995333) Homepage Journal

    I can't speak for anyone else, but usually the only reason why that happens in my own case is if there's something in there that has hardened and is sticking into the wall of one of my nostrils, and it itches, or even hurts.

    So to remove the pain, I remove the source of it. ;)

Science and religion are in full accord but science and faith are in complete discord.

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