The prenatal wages of interracial relationships

23% is considered a low rate of caesarean ?

This fits with what I have read about high SES women asking for caesareans and getting them from litigation adverse doctors, worried about being sued if anything goes wrong with a natural birth or "vaginal delivery" as it is now known in some circles.

It's my impression that in a relatively high proportion of Thai/Filipino Asian woman white man couples the man is much older. This may affect things such as the incidence schizophrenia in their children for reasons that are not directly conected with geographical genetic variation.

It's my impression that in a relatively high proportion of Thai/Filipino Asian woman white man couples the man is much older. This may affect things such as the incidence schizophrenia in their children for reasons that are not directly conected with geographical genetic variation.

this is a good point. but in the USA we do have large populations, like japanese americans, where race is the primary variable you would test.

Gestational diabetes and near-diabetes makes for huge babies. You don't need a pelvic-size hypothesis to explain the increased caesarean rate - they should have looked at birthweight.

As for those observant male colleagues, it has been my observation that pelvic tilt is the real variable, not just size. In both genders. (And regional preferences for sexual position do seem to correlate - there's a reason they called it the "missionary" position).

I am skeptical about conclusion of pelvic sizes between white vs asian females. Asian, at least Chinese babies have birth weight heavier than pure Caucasian babies. So Chinese women pelvis can not be smaller than white women. Yes, white women might have more flesh outside pelvic bone which might give wrong visual impression of pelvic size. But pelive bone size is really matter for the birth. At least Rushton had some imformation about aisian babies weight.

As previous commenter, it is likely psychological factors behind the difference of c-section rates.

On the other hand, gestation diabitis is higher in Chinese women. Ironically, babie always are heavy and large in gestion diabetis. So heavy babie weight in Asians might have some thing to do with this condition.

"incidence of gestational diabetes was lowest among white couples at 1.61 percent and highest among Asian couples at 5.73 percent - and just under 4 percent for Asian-white couples."

I think we should separate actual interaction effects like hapK from cases like these where the mixed individual tends toward one parent. Case in point:

"Racially mixed individuals in Hawaii seem to be more likely to be obese;"

There were actually not many categories in that study where mixed individuals were significantly fatter than BOTH of the parent races, and you have to wonder if there is something special about Hawaiian admixture, like many did in the comments of that post. Their comparison was to the average of the two ethnic groups. For example, Asian/White, Black/White and Latino/White individuals were all closer to the heavier parent race but not significantly over in any category. I don't think that warrants the conclusion that racially mixed individuals are more likely to be obese.

I'm not going to speak to the C-Sections, that seems obvious but could the diabetes thing be as simple as Asian women married to white males tend to eat more Western food, which their bodies don't metabolize as well making them more likely to get diabetes? Asian Americans have a high obesity rate, but it is not commonly talked about.

"Asians, especially those from Far Eastern nations like China, Korea and Japan, are acutely susceptible to Type 2 diabetes, the most common form of the disease and the subject of this series. They develop it at far lower weights than people of other races, studies show; at any weight, they are 60 percent more likely to get the disease than whites.

And that peril is compounded by recent immigrants' sudden collision with American culture. Many of them left places where factory and fieldwork was strenuous, televisions were rare and advertising was limited. They may speak little English and have poor access to medical care.

Many have never even heard of diabetes, much less the recent scientific studies showing that a Western diet, high in fat and sugar, puts them in danger of getting Type 2 diabetes, which has been linked to obesity and inactivity, as well as to heredity. (Type 1, which comprises only 5 percent to 10 percent of cases, is not associated with behavior, and is believed to stem almost entirely from genetic factors.)

Many recent Chinese immigrants have come from places where food was scarce, and experts say some view fat as a trophy of wealth and status. Their children try to fit into their new country by embracing its foods and its sedentary pastimes."

http://www.nytimes.com/2006/01/12/nyregion/nyregionspecial5/12diabetes…

AG said:
I am skeptical about conclusion of pelvic sizes between White vs Asian females

As someone who was born in Ireland and lives in New York, and exposed to a huge selection of ethnicities daily, I would definitely say that East Asian female pelvic widths are much less than European pelvic widths in general, even allowing for overall smaller sizes of East Asians.

IMO European women display considerably different pelvic widths, based on their geographic location. In general Mediterraneans (including Jews), some Scandinavians, Northern English and South East Europeans tend to have wider pelvises, while women from the North European plain (Holland, Northern Germany, Northern Poland) and much of Eastern Europe tend to have narrower pelvises. So there are geographical differences.

. In general Mediterraneans (including Jews), some Scandinavians, Northern English and South East Europeans tend to have wider pelvises, while women from the North European plain (Holland, Northern Germany, Northern Poland) and much of Eastern Europe tend to have narrower pelvises. So there are geographical differences.

LOL. wow, you're specific paul.

could the diabetes thing be as simple as Asian women married to white males tend to eat more Western food, which their bodies don't metabolize as well making them more likely to get diabetes?

No, the risk is lower for Asian women having babies with white men than for Asian women having babies with Asians (4% vs 5.73%)

I'm filled with admiration for Paul's powers of observation, but it's a bit of a worry that he's been taking such detailed notes :)

What really matters is the size of the baby's head in relation to the size of the birth canal. Pelvic size, or at least hip width, may not be a perfect proxy for the size and shape of the birth canal, and birth weight may not be a perfect proxy for head size. Confounding factors could be the incidence of breach births, and the fact that some women elect to have caesarian deliveries for cosmetic reasons or to avoid the intense pain of vaginal delivery. Plus Tod's observation about high SES women.

African women have narrower hips than European women, but their pelvises are deeper. Babies' heads are plastic to some extent. And the pelvis does expand somewhat during birth, and never completely resumes its original size.

Obesity and lack of physical fitness in the mother are other possible confounding factors. Slim, fit women have less difficult births. Asian women may be slimmer and smaller, but they might not be fitter physically.

It also depends how they have grouped people racially. I don't have Paul's notes in front of me, but in my extensive personal observation, Indian women tend to be generously hipped, maybe even more so than those big-arsed northern English sheilas. For the purpose of examining mother's pelvis size as a factor in birth difficulties in racially mixed marriages, grouping them with Asians would be confounding, and for that purpose at least I would be classifying a European male/Indian female marriage and vice versa as "not mixed" and grouping Indians and Europeans together.

I'm not saying it's wrong necessarily, but it is very broad brush.

Razib:

Slightly off topic, as I see your point, but your example of African Americans having heightened risk of heart problems is still up for debate. As was discussed last year on the old site, it appears hypertension is only higher in African Americans, but not in other admixed black New World Populations, like Jamaicans, and African Americans are still lower than many Western European groups. It's obviously something more complex...some thought maybe it has to do with latitude...

http://www.haloscan.com/comments/raldanash/7609577490345040697?url=http…

Vietnamese are a small people with big heads for their body size.
It is my impression that Koreans have very large heads. There are SES differences too.
A study said to refute suggestions of the adverse effects of interracial mating was criticised for using Hawaii on the grounds that the average "black" person there has a lot of non-black ancestry.

Perhaps this type of analysis could be the next significant revenue stream for companies like Decode and 23andMe - a dating site where you are pre-matched to potential partners, chosen with the intent of maximizing offspring viability.

Is this something that can be done today, or is the technology not 'there' yet?

"Although the probability of heart attack is raised in people who are overweight, have a thick waist relative to their hips, smoke and are in a low socio-economic group, statistical tests suggest that finger ratios predict age at heart attack independently of these life-style factors. However these same tests suggest that lifestyle factors remain independent indicators of raised risk of heart disease. Male mean ratio for a sample of Jamaican men is 0.93 "Female type finger ratios are related to high levels of fibrinogen and thyroid stimulating hormone"
from The Finger Book (2008 Faber and Faber)by John Manning

@stagyar
check out genepartner,

http://www.genepartner.com/

they don't, as of yet anyways, advertise checking for pelvic to infant head ratios. but maybe u could convince them otherwise.

Sandgroper, Wongba,

I take pelvic size seriously, I have to!

My Mom's family hails from Northern England, and most of the women have hour-glass figures, with extra wide pelvises. The family also has a tendency to have large heads - but with this combination, no problems.

My daughter's French/Italian mother was on the more athletic side - her dad was an olympic sprinter for France - and had a somewhat narrower then average sized pelvis.

At birth our daughter's head was in the 97.5% for size, and was a full 2 inches wider then her mother's pelvis - so she had to be delivered via C-section. In earlier times, one or both may have died in childbirth!