Siamangs are <i>hylobates syndactylus</i> while Gibbons are <i>hylobates lar</a>. Siamangs live in nuclear family units and tend to be a bit more closely bonded to their mates than do Gibbons.
Chimps and bonobos both engage in plenty of nonreproductive sex. They practice oral sex, manual genital stimulation, ‘french kissing’ and homosexuality(both sexually and in pairing). Incest is not known. They are promiscous, the females as much, if not more than the males.
In answer to your second question, I have yet to read of a detailed study of sperm in other primates. If I do, I’ll be sure to let you know what was discovered.
I don’t mean we should sleep with everyone we want, but neither do I believe people should be forced to stay with the same mate just because society believes that’s the right thing to do. See my other example about my wife-beating first cousin.
We definitely have a pair-bonding instinct, so some degree of monogamy is the natural state of man. There are definite advantages for raising children, as well as for hunting.
I’m not sure I agree with the notion that we’re the most complicated organism (at least not without knowing in what sense), but the actual differences in our behavior are much smaller than the similarities.
My own opinion is that the desire to mate exclusively with one person for life, and the desire to have sex with as many people as possible, are both natural to human beings. Yes, we have contadictory desires. That’s what makes life… interesting.
Humans don’t have any instincts at all, let alone a ‘pair-bonding instinct’. Pair bonding in humans is cultural. See other cultures where they don’t have pair bonding but have different forms of polygyny (i.e. woman with multiple male mates or male with multiple female mates).
Fallacy: we aren’t “meant to be” anything at all; there is no “meaning” involved. (Meaning is something humans make after the fact, in their own heads.) In fact, evolution requires that there be some distribution on this subject – otherwise there would be nothing for selection pressures to act upon.
The general biological tendency of humans (on average; again, specific cases vary widely) seems to be, in my opinion, some form of social-monogamy-and-cheat-whenever-you-can-get-away-with-it, with perhaps mild tendencies towards polygyny; the biological adaptations for sperm-competition and the like aren’t as extreme in humans as they are in bonobos, but they’re significantly more noticeable than that in gorillas, which do harem-based mating in which the female gorillas don’t have much opportunity for extracurriculars. Humans also don’t have much size dimorphism, which correlates positively with monogamous tendencies. (Gorilla-level size dimorphism correlates with strong polygyny – the silverback can dominate his harem with sheer mass.)
The societal stuff massively modifies the raw biology, though. (And some of the societal stuff that happens strikes me as very weird; there’s a significant undercurrent in the current-day American mainstream that ranks cheating as superior to honest multiple relationships, which just breaks my head.) And, again, individuals will differ – some having no preference as to relationship structure, others having pretty much orientations towards either monogamy or some form of multiple-partner system, and the whole spectrum in between, complete with bizarre embellishments.
The Myth of Monogamy is a fascinating book, incidentally.
:dubious: Really? Care to name some instincts that humans have? Humans have instinctual DRIVES…not instinctual BEHAVIORS. And pair-bonding would be an instintual BEHAVIOR. So would hunting. If I’m remembering correctly, instinctive drives are things like sex or aggressive behavior…i.e. almost reflexive actions.
Now, admittadly its been something like 20 years since I took anthropology in college and I haven’t exactly kept current. So, if I’m wrong about human instinctive behaviors like pair-bonding, be so good as to do more to disprove me than merely saying ‘bullshit’…after all, we ARE all about fighting ingnorance here, yes? At least explain yourself in a more concise way than ‘bullshit’ next time.
And in modern western society, we place ourselves in such stressful situations that I think we would be hard pressed to claim that however we behave under these circumstances is in any way our natural state.
I recall a long-ago article examining some particular African tribe that still lives a hunter-gatherer existence. A man of the tribe explained their marital practices thusly: "A man has only one wife, but many ‘friends’ ". That may be as close to our natural state as we are ever likely to discover.
Chimps and bonobos are not naturally honest. I remember reading about experiments in which it was shown they will hide food from one another and deliberately decieve the other about its location (or something like that). Humans are not naturally honest either; we never refrain from stealing or telling lies to our advantage without heavy societal influence and coercion. Is it wrong for society to expect people not to lie and steal?
Suppose anthropologists discover that our upright stance evolved not to facilitate hunting animals on the plains, but to facilitate killing neighboring humans, taking their resources and forcing the surviving females to mate with us. Should I change my weekend plans on this basis?
Supose it is natural for adult males to mate with with females as soon as they achieve menarche?
And is our drive to create a society that overcomes what we now regard as “primitive” behavior any less natural to us than whatever sex drives we may have inherited from our evolutionary forebears?
I believe I read the testicle-size argument in Nature Via Nurture[sup]1[/sup] (now called The Agile Gene or something like that) by Matt Ridley, as well as in Skipping Towards Gomorrah by Dan Savage. They both presented the evidence that John Mace did above: gorillas are polygynous and the males have little sperm competition, so their testicles are relatively small; chimpanzees are like a perpetual free-love festival where every male mates with every female repeatedly, so their testicles are gigantic as they try to outproduce each other. Human testicle size falls in between the two, which indicates that we evolved in an environment of monogamy, plus plenty of cheating going around.
I can post the relevant passages if anybody is interested.
[sup]1[/sup]Or was it Genome? No, I think it was Nature Via Nurture. Hmm. Now I’d better go find out for sure.
Speaking strictly from a biological standpoint, and disregarding any cultural, social or biblical impositions on the subject, the physical shape or design of the male penis is the key here. The plunger style shape of the head of the organ ( Glans ) is specifically shaped to remove or withdraw the semen from any male that was there before. This method more insures a higher percentage of the last male on the scene ( usually the biggest and badess guy ) in having his offspring come into the world.
A monogamous basis of sex and procreation, at least in higher primates, would have no use for such a design.
Monogamy is a cultural imposition on the natural order of our nature, and while it has shown much merit in the modern world, it has also contributed to much strife and frustration.
An excelent point, scotandrsn. It’s also worth noting that we don’t practice polygamy because we have plunger-shaped penii. It’s the other way around. Plunger-shaped penii were an advantageous adaptation only because our forebears were already sleeping around. These adaptations are evidence that we and our forbears have been practicing polygamy for a very long time, and nothing else.
Thinking of what we’ve been doing for a very long time as our “nature” and what we’ve been doing more recently as a “culture” that has been artificially suoerimposed on it is itself a very culturally-linked way of looking at things, and a rather outdated, pre-scientific one at that! I’m used to hearing discussions of human “nature” in theology, not biology!
The natural state of human beings, for what it’s worth, is to have our drives molded by our culture. We evolved to be cultural beings. Our brains don’t develop properly without some cultural matrix, and we lack the instincts and physical adaptations necessary to survive without culture. As our brains became more advanced and complex, it became more efficient to pass on much of what is necessary for survival through culture rather than genetics. It is entirely possible (though of courese extremely specualtive to suggest) that if we hadn’t evolved and developed so as to create cultures which (universally, though in different ways) severely restricted our sexual activity, then we would have evolved a stronger instinctive tendancy towards monogamy!
I don’t think there is a man around who wouldn’t think it was preferable to have more than one wife if he could afford it and his wives were willing.
On the other hand I don’t think many women would consider having more than one husband as desirable. Weird because we all know that women are much more capable at multi-tasking.
That is not to say that women are incapable of extra marital sex.
This is a popular belief; I have never actually seen any evidence for it in the populations of actual people with multi-spousal relationships I’m familiar with. (Gender unspecified; a fair number of the folks I know in said multi-spousal relationship systems are bisexual.)
I do have the impression that “single spouse, multiple ‘friends’” as described above is significantly more popular than true polygamy (or the closest approximation thereof as is manageable in the locality).