Cultural gender imbalance

Dave comments on "liberal eugenics" about the issues of being able to chose the sex of one's children.

Currently we use "biological planning", but what would market production of babies be? Assume everyone could chose the sex of their children.

As a marxist would put it, it is men's "gender interest" to produce women and women's interest to produce men... indeed theoretically more women than men benefits men whose value increase and vice versa. Not quite true. First of all, it seems that wanting to produce men is a general bias... if cultures are patriarchal (gosh now I sound marxist AND feminist), it is indeed an evolutionnary advantage to breed boys that will spread your culture. Second, it seems that in societies with a deficit of women, rather than women's value increasing women tend to be treated more like commodity... if the women are no self-owners their scarcity is more of a curse. It is possible that with increased gender imbalance these tendencies invert, but it is also possible to imagine that the majoritarian gender gets power and control thus creating an incentive to increase the imbalance.

These arguments ignore the multiplicity of cultures, and surely different culture would have different gender ratios. Which culture would be at a reproductive - hence cultural - advantage thereby spreading this ratio? My guess is that it would be a polygynous society. There are two reasons for this.

- Biologicaly eggs are the limiting reagent not sperm, it is currently a waste to raise so many males
- Less men and more women means less deadly competition among males. Since males are naturally more violent is is more efficient than the opposite.

Why didn't such a ratio evolve biologically? Well it may give a specie an advtange over another specie but it does not give a reproductive advantage to an individual within a given specie. If I live in a 50/50 society, having more daughters will not guarantee me more grandchildren therefore the mutation is lost.

In the distant futures, with biotechs, we might live in such a society (but let's not be utopians).

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Are you advocating incest?

Actually from a genetic standpoint it's in a man's interest to produce whichever sex is in a deficit.   That's because his children will then have the gender edge and be more likely to pass on his genes.  

Even with your incorrect assumptions that it's in personal his interest to increase the female/male ration, it's only in his interest that other men produce women, not that he himself do so.   That is, unless, you think he's going to practice incest.

It's never good to think like a Marxist.  Their ideas are so screwed up they don't even work in their original context.   So it's not surprising they don't work in analogous situations.

To clear things up I

To clear things up I mentionned a "gender interest" as a tongue-in-cheek argument, I
do not take it seriously. No I am not relying on marxist assumption nor
am I advocating incest. If there were such a thing as a "gender
interest" it's fun to say what it'd be that 's all. My post is mostly about how cultural evolution could bring gender imbalance.

Now it is true from a genetic standpoint that it is in a man's interest to produce whichever gender is in deficit since there are more children per member of said sex, that's an interesting feedback mechanism I didn't think of. Would there be a strong instinct to do so? Cultures overcoming that instinct would still produce more children. It may be in the individual's interest to correct the gender imbalance but the specie's interest to have a gender imbalance. Funny.

Well not completely clear

Sorry to nit-pick but you are talking with a biology-geek. I don’t know squat about baseball or cricket if that a consolation.

”Would there be a strong instinct to do so?”

Well and instinct implies that some neural function is involved in selecting the sex of the offspring. The normal mechanisms that control this are not neural. Those mechanisms have been researched and the do tend to produce a 50/50 investment in the sexes by cost. If males are larger and require care then less are produced. These mechanisms range from the natural propensity of meiosis to produce half Y sperm and half X, to differential female control of sperm success via vaginal conditions, and female nesting site selection in those species where sex is determined by incubation temperature.

”Cultures overcoming that instinct would still produce more children.”

The claim is that humans don’t possess instincts as defined by scientists. Also changing the sex ratio in and of itself does not guarantee and increased production of children in a species where males contribute to child rearing.

For instance, in certain Penguins any increased females would just have to abandon their young to feed, leaving them to their deaths. Obviously, in seahorses, where the male exclusively cares for the young this wouldn’t work. So “it depends” is a strong factor in actual production of children.

Note also that production of children is not a accurate measure of fitness, many species kill off their excess young if conditions do not allow for feeding all the offspring initially produced. One can overproduce offspring.

”It may be in the individual's interest to correct the gender imbalance but the specie's interest to have a gender imbalance. Funny.”

This is a curious statement. From who’s perspective is it an imbalance? You seem to think the “species interest” is to have more females, and if so then wouldn’t a 50/50 split be an imbalance? I only say that because you used the word “correct” which is a normative verb.

The main problem however is that there is no “species interest”. To have an “interest” you need an actor, and a species is not a cohesive enough unit to be considered an actor. Why would the “species” care about how many offspring are produced per generation? What’s in it for the species?

How does what you think is in it for “the species” balance against other factors. Having a small male population is a genetic chokepoint. To see this clearly imagine that only one male is retained per generation. After many generations the genetic variance of the population would drop dramatically. This would leave it open to attack by other organisms as they crack the simplified code. Germs would learn how to attack and spread easily through such a homogenous population.

I suggest you pick up Dawkins’ “The Selfish Gene” as an initial introduction to these issues. It’s a great read in common prose. You will feel like a genius as you read it. I wish I could write like Dawkins.

<i>Well and instinct implies

<i>Well and instinct implies that some neural function is involved in
selecting the sex of the offspring. The normal mechanisms that control
this are not neural.</i>

Please read my blog entry, the whole point is to describe a situation where the choice of the sex of children is neural, it's even fully conscious. A genetic propension to have more of the minority gender would be irrelevant since by hypothesis the gender ratio would be a conscious choice, so unless an individual has an instinct (yeah neural) to spread its genes by producing the minority gender, this feedback mechanism would not prevent the emergence of a gender biased population.

<i>Also changing the sex ratio in and of itself does not guarantee and
increased production of children in a species where males contribute to
child rearing.</i>

It does not guarantee anything but it does provide a way to produce children with strictly less ressources, since even though male contribute to child rearing, there are still more men than necessary.

<i>For instance, in certain Penguins any increased females would just have
to abandon their young to feed, leaving them to their deaths.</i>

Sure there are even many species where overpopulation is a concern and is regulated by the food supply, that's why I said "it may be". I'm concentrating on humans, not penguins or seahorses.

<i> I only say that because you used the word “correct” which is a normative verb.</i>

Alright now you really <b>are</b> nitpicking... there was nothing normative here, I just meant push back towards 1:1 which is aprox the natural biological ratio as far as human are concerned.

<i>The main problem however is that there is no “species interest”. To
have an “interest” you need an actor, and a species is not a cohesive
enough unit to be considered an actor. Why would the “species” care
about how many offspring are produced per generation? What’s in it for
the species?</i>

You could say the same thing for individuals, what's "in it" for them to spread their genes? Well same goes for species, there's nothing "in it" for the specie to produce more offspring with less ressources, but it sures make it easier for the specie to perpetuate. Species appear and disappear, producing more children with less ressources provides higher fitness for the specie that's all.

<i>Having a small male population is a genetic chokepoint. To see this
clearly imagine that only one male is retained per generation. After
many generations the genetic variance of the population would drop
dramatically.</i>

Fair enough, but this lower genetic diversity would be balanced by the lower amount of ressources needed so the ratio of male may still lie between 0 and 50%.

One other point is that a culture with a bias for producing more men would spread widely through a culture with a bias for producing more women hence removing the bias, however a somewhat endogamic (for women) society with a bias for producing women may very well outnumber other cultures. Actually in many cases, a man marrying a foreign woman is perceived as acceptable while the reverse is not.

Species aren't agent like

"Please read my blog entry, the whole point is to describe a situation where the choice of the sex of children is neural, it's even fully conscious."

I read the entry but was responding to the comment about instinct. In that case you are dead wrong in the comment since humans have no instincts. Throughout your blog entry and your comments you've been shifting between culturally and genetically mitigated factors. You confused the two in the article even if you don't in your mind. For instance, you said, ".. It
is indeed an evolutionary advantage to breed boys that will spread
your culture."
This makes little sense and only would if you disentangle the genetic from the cultural.

"... this feedback mechanism would not prevent the emergence of a gender biased population."

I wasn't claiming that culture or mental choices can't override genetics. My wife had me spayed so I know this at a personal level. Damn vet.

"It does not guarantee anything but it does provide a way to produce
children with strictly less resources, since even though male
contribute to child rearing, there are still more men than necessary."

You are thinking that males are like drones in a bee hive, a zero sum game. No, males actually produce and often in excess of their "cost". All this will depend on the species and the environment. In humans we are a net plus.

There's no reason you couldn't have a species where having two males per female might be the best way to go. Especially if all the female does is lay around producing eggs and not gathering food. In fact if by chance the genetics of the bee were different then the males would have been the workers and the females the drones. In which case the excess workers males per female would be a net plus ... for the hive (again not the species).

" there was nothing normative here"

I thought so but just in case. :)

"You could say the same thing for individuals, what's "in it" for them to spread their genes?"

No you can't. Individuals are the unit of selection and action. All the genes in the same individual sink or swim together. Since they are in the same boat they have evolved to cooperate slavishly as a unit. The same is not true of the individuals of a species. Heck, me and several thousand of the most beautiful and intelligent women in the world could isolate and exterminate the rest of you "humans" ala Moonraker and the species would go on just fine.

If we use "care" to mean "have an interest in" then individuals do have an interest in their children, a genetic interest. The species is just a collective that doesn't share interest in the same way. The same cannot be said for cultural organizations but I'm talking about species not organizations.

"Species appear and disappear, producing more children with less resources provides higher fitness for the specie that's all."

Then why aren't we all bacteria?

"Fair enough, but this lower genetic diversity would be balanced by the
lower amount of resources needed so the ratio of male may still lie
between 0 and 50%."

The same can be achieved by producing the same number but smaller males. When resources are at an extreme premium this sort of thing can happen. Thus, we get the tiny parasitic males of the anglerfish, or the tiny males of the ant colony. Ant colonies naturally invest less resources in males because they don't produce resources themselves (and for other reasons).

Overall I am saying you are not taking all the factors into account. What seem like nitpicking factors often are the crux of the matter. I still suggest you read Dawkins book since it condenses more than a hundred years of thinking into what is a very short read. I betcha can read it in a weekend.

You've got some correct notions about what's going on but you are placing the self-interest in the wrong entities. Replicators and collections of replicators can have interests. Things like viruses, single celled organisms, organisms, genetically tied colonies, companies, governments, armies, tribes, can share interests tightly enough for the idea of agency and interests to make sense. The chief of a tribe is analogous to the brain of a body. Species don't have "leaders" or "overlords".

I've taken several college level courses on zoology, botany, population genetics and the like, but I've actually learned more about all this outside of college. I'm in my forties and continue to read this stuff. So take this as constructive criticism. I'm actually trying to be helpful. I was being intentionally self demeaning in calling my comments nitpicking. I leave you to figure out why.

Then why aren't we all

Then why aren't we all bacteria?

Statistically we mostly are.

You forgot the most

You forgot the most important part: more women than men ==> increased threesome likelihood.