Evolutionary Monogamy

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I haven’t been following this thread as closely as I perhaps should have, but since my name’s been mentioned (twice!), I can’t resist adding my two cents .

I suppose it depends on what is meant by “pair bonding”. If we mean simply a couple staying together for life and being comfortable with and faithful to one another, then there are of course numerous examples of that. If, however, we are referring to a situation where two people are completely devoted to each other, absolutely in love, and where life without each other would be completely devoid of meaning – that’s different, and I suspect much rarer.

 

The program's definition of "pair bonding" is much closer to the former of your definitions.

Basically, two people being together (most likely married, but probably not required). One would assume they are in love. They would be comfortable with one another and faithful to one another. In no way did the program indicate that their life would be meaningless if the other wasn't there.

EDIT: Spelling

[ August 10, 2004, 18:57: Message edited by: Aldeth the Foppish Idiot ]

 

Digging way back to my undergrad days, I remember a link established between monogamy and the lifespan of women in a given society in the classical world. Ancient Athens practiced serial monogamy with lots of divorce, but they also had a major woman-shortage because Athenian women died so young that serial monogamy was the only way a majority of men could have a woman at all. In civilisations such as Sparta, where women ate better and had better standards of living, they therefore had much longer lifespans than the Athenian women (in fact I seem to recall that Sparta had a larger female than male population), and marriage was not highly valued (people did marry, but they didn't usually live together and there was no real culture of romance). In ancient Hebrew civilisations, women were treated considerably better than in many other cultures, so there were more of them and polygamy became feasible. Our society has more women than men, unlike it did in say the 1960s, so it's not surprising that we don't see romance and marriage as important anymore. Although I personally am pair-bonded and plan to stay that way, demographics be damned.

 

That's intersting, an egg and hen problem. I'm inclined to still think that the life-span of a woman in living in monogamy is much shorter then the life-span of a woman living in polygamy because the former lives in a monogamy. Or in other words, serial monogamy is a consequence of monogamy itself. The main reason for a woman to die is giving birth. That would be a death-ratio before the invention of sterilisation of instruments of approx. 1/8. That would make the propability of death after 4 births a little bit less then 50% (7^4/8^4). That would mean that a woman can be with nearly 50% certainty expected to die in the childbed before reaching 26, given that she married with 16 or 17.

I'm highly inclined to think that the birth-per-woman-ratio is lesser in polygamy than monogamy, making the lifespan of a polygamous woman reasonably longer.

In this case, why didn't the Athenians switch to polygamy ? Given that I still think that polygamy is the result of constraint of resources in an agricultural society and that Athens grew very rich, what made them keep their traditions ?

 

Because in order for a marriage to be legal and the children legitimate, both the mother and father had to be Athenian citizens, and in addition the father and mother of the married couple also on both sides, had to be Athenian citizens as well. Therefore marriage with slaves, hetairai (they were something like the japanese gheisha) or women from other greek cities was out of question and the number of women with athenian citizenship wasn't enough in order to switch to polygamy.

 

The main reason that women in certain civilisations have lower lifespans than in others is malnutrition. Even childbirth deaths are directly correlated to malnutrition - which is why in modern countries with socialised medicine, where the rich and poor get the exact same obstetrical care, poor women are still more likely to die in childbirth than rich women. And in ancient Athens women were truly second-class citizens; they did not eat as well as men, and they did a lot of hard manual labour.

But you're right, Iago, it's still a chicken-egg problem. If men treated their wives better, there would have been more women alive of marriageable age, and polygamy would have been feasible. And from the other perspective, if they saw women as valuable enough to treat well, they might be more likely to want more than one woman.

 

BOC: That's probably why they haven't changed, as those rules where literally written in stone, I suppose

Sprite: I think you might be right about the correlation with malnutrition in the later half of the 20th century. But I think more so worse medical care. But around the world, the invention of sterilisation and desinfection was a quantum leap . Sterilisation was invented by a doctor who was working in a maternity hospital and it lowered the chance of a woman in childbed to die about 1000 times. So, before the end of the 19th centrury, a woman everywhere and of every financial status was most likely to die in childbed from childbedfever or something else. Yet, I think the likelyhood was less for the financially better situated because of coincidental better containment of their surroundings.

 

Well, the term "most likely" is a bit of an exaggeration. Large families in ancient times were not uncommon. Having 5 or more children wasn't seen as unusual. If you were "most likely" to die while giving birth, the chance of any woman having more than one or two kids is vanishingly small.

 

Well, if you read my posts above again, I say that the chance to die in childbed was approx. 1/8. And as you said, 5 and more children family were the usual thing. If the chance to survive one birth is 7/8, the chance to die approaches (thumb-guessed) approx 55%. Both mixed together yields the known picture that the number one death cause for women was dying in the childbed. And the normal family then would have 8 children, one father who married again and his first wife died at the birth of the 4th child. Or 5 children and no step-mother.

Ok, I confess, I suck at math. But still think that's even simple enough for me. The chance to survive is 7/8. The chance to survive two times in a row is 49/64. The chance to survive three times is 343/512... 2401/4096 ~56 percent chance to survive 4 children.

Couldn't find any good source with numbers except that. But the impression is screwed a little bit, as maternal deaths rose dramatically at the end of the 17th century with the coming of hospitals and other breeding places for deseases. Yet, the survival chance before the 17th century weren't too big neither. And there were of course other infections too.

http://www.ivillage.co.uk/pregnancyandbaby/pregnancy/labour/articles/0,,17_183521,00.html

 

I undestand what you mean. My point was - and I admit I didn't do a good job of explaining it - was that if your chances are 1/8 that you are going to die, then there is a 7/8 chance that you are going to live. Therefore, you are "most likely" NOT going to die.

 

You know, I wonder if the premise of the original argument even works. If a man doesn't know whether a woman is ovulating, isn't he likely to try to procreate with as many women as possible to ensure that one of them gets pregnant? This is just what I think from an evolutionary, instinct-based viewpoint. I think that a tendency toward monogamy or polygamy is an individual issue, not one for the species.

 

This topic reminds me of a Simpson's episode I just made up...

Prof. Frink is behind a two-way mirror watching a family. He exclaims, "Mmm GlAvin...why do these HUmanz spend so much time together, er, er..?"

Silly Professor, the answer is love!

There is a direct correlation between the size of a primate's brain and the size of its social group. Despite what Frinky may think, the impetus of brain growth was not to better understand the world around the early anthropoids (or early zany scientists), but to better understand one another! Our ability to "think" is often an inner monologue, correct? At least that is the way my brain tends to operate... So my thinking is in fact...communication! I understand the world not through my own observations, but through my ability to express them to someone else!

This is why people often see a human face behind things they do not understand. I am going to make up a word here...anthropomorphication (if it already exists, I still rule). This is the molding of the external world to facilitate our ability to understand it by making it another person. Prime examples would be...hmm...maybe saying a spider is scared. Better yet, how about the Romans seeing a human carrying the sun around the sky. Even better, modern man wonders how the universe was created and sees a human consiousness as the Creator. An incredibly powerful human consciousness, but a human conciousness none the less (he's even vengeful...and he's a he). This is not to say there is no God, but the fact humanity says we are similar is, well, so egocentric that it almost insinuates we are incapable of viewing the world in non-human terms. *wink wink*

I'm cooking up a theory but it is far from complete. Basically, love is a mechanism by which higher forms of life facilitate vast amounts of communication simply for the chemical reward of communicating. This causes a more thorough understanding of the world as it provides a more differentiated human conciousness with which to mold the world into. This is an adaption which natural selection would favor as it allows for a more "intelligent" animal, albeit an egocentric one. Unfortunetly, I cannot get mathematics to fit into any of this...does anyone know if math is a fundamentally different function of the human mind? Hmm...mathematics seems a very visual affair...maybe that has something to do with it...don't know...

Also, most mammilian males will kill the young offspring of a rival male if he is removed. This purpetuates his own genetic line. Considering the length of time it takes the young of highly social animals to become self-sufficient, an extension of the normal pair-bonding period seems a natural consequence. Also, highly social animals need to understand the effects of gender upon their social network, particulary its effect upon love as it is a vital impetus of learning. Once base instinct is surpassed, all else must be taught and this can take a long, long time.

Another theory is called the Grandparents Effect. Long term monogamy allows grandparents and extended families to remain united. This allows the parents to hunt and gather while their young are cared for, and taught, by the grandparents. Hmm...maybe I should have led with this paragraph...

 

Except that way - if all men did this - then you would never know for certain which children were yours, if any in fact were. By staying with one woman, and having sex with her regularly, you guarantee that you'll be the father.