Evolution study- As human heads grew, so did human penises.

Discussion in 'Sex With a Large Penis' started by D_Tallie_Wacker, Feb 1, 2011.

  1. D_Tallie_Wacker

    D_Tallie_Wacker Account Disabled

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    As human heads grew, so did human penises

    [​IMG] Esther Inglis-Arkell — [​IMG]The reward for big brains may not be art, culture, comfort, or even basic survival. Instead, it may just be the development of larger penises.
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    The great apes are bigger than humans in a lot of ways. A lot of them have overall size on us. Because they're not sitting around in swivel chairs all day they generally have bigger muscles. But there are at least two parts of the human body that surpass our ape cousins' in size: heads and penises. It turns out that these two things are not unrelated.


    Tiny little chimp brains can be contained in tiny little chimp heads. And tiny little chimp heads can be easily birthed. As humans needed larger brains in order to acquire language, imagination, and the ability to learn, their heads needed to expand along with everything else. In order for large-headed human infants to come out of human females, the birth canals of human females needed to expand.


    These expanded birth canals meant competition was on as to whose sperm could get to the end of it in order to do some impregnating. There are only a few ways to do this. Either super-charged sperm can race down the birth canal or regular sperm can be given a 'head start'. The larger heads of infants lead to larger birth canals, which in turn lead human males to have much larger penises than the great apes.


    Just don't tell that to a silverback gorilla.


    Originally found posted here io9. We come from the future.


    So, what do you think of the theory?
     
  2. bruce-san

    bruce-san New Member

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    That's an interesting idea. Seems plausible enough. I find more interesting why our brains began to expand in the first place.
     
  3. D_Tallie_Wacker

    D_Tallie_Wacker Account Disabled

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    It makes me wonder whether there is also a link between head size and penis size in individuals, as someone who has a relatively small head and isn't large, lol.
     
  4. bruce-san

    bruce-san New Member

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    Nah, doubt it.
     
  5. PerfectlySexy

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    Anyone interested in recent biological theories around human genitals (and other biology) and mating behaviors, which does make for fascinating reading, should check out the book Sex at Dawn:

    Sex at Dawn
     
  6. MarkLondon

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    It strikes me as a plausible hypothesis. Another consideration is our bipedalism, which I recall from reading Elaine Morgan's Descent of Woman back in the 1970s resulted in a change of position (and maybe length?) of the vagina.
     
  7. PerfectlySexy

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    To answer the questions, yes this is plausible but no, it would not mean a correlation in individuals for head size and penis size (at least not in any noticeable way). And by plausible, I mean one should not discount alternative hypotheses. What if, for example, men developed larger penises to better compete with other men for fertilization and women's vaginas grew larger over time in response to that, thus leading to children with larger heads having increased survival rates... Ok, that doesn't sound as likely but it's good to stay open to possibilities.
     
  8. B_subgirrl

    B_subgirrl New Member

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    #8 B_subgirrl, Feb 2, 2011
    Last edited: Feb 2, 2011
  9. RawDog

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    I think the logic is sound. What could possibly further the research is by taking measurements within members of the same gene pool. Like several Dutch families and compare it with families from Borneo.
     
    #9 RawDog, Feb 2, 2011
    Last edited: Feb 2, 2011
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