Understanding Scientific Studies for Swayers 2 - Famines and Fertility
Understanding Scientific Studies for Swayers 2 – Scientific Support for Trivers Willard Hypothesis
Please read Part One of this essay here: http://genderdreaming.com/forum/sway...s-swayers.html
Even though we have a lack of good studies to work with, instinctively it seems that at the least we should have a plethora of data in support of Trivers Willard. All we’d have to do is look at data from famines and then we’d expect to see a shift in the gender ratio every time there was one. And countries that are poor would always be having more girls than is statistically expected.
But the results have been mixed. While some studies do seem to support TWH, others have not. Chinese Famine Led to More Female Births | Science | AAAS
Poor countries do tend to have more girls than is statistically expected, List of countries by sex ratio - Wikipedia (please ignore data that comes from countries where sex-selective abortion is done – these are the ones with impossibly high sex ratio 1.08 and up) but we are not sure if this is due to diet, or an artifact of the fact that more girls are conceived around the equator for reasons we do not understand and most poor countries are equatorial The equatorial enigma: Why are more girls than boys born in the Tropics ? and what does it mean? | The Independent The authors of this study claim to have corrected for income in the study. I personally don’t believe it’s JUST the equator in and of itself however, because if you look at the list of countries by sex ratio I posted above, there are equatorial countries like Nigeria with normal sex ratios and countries far from the equator with skewed ones, like Finland and South Africa.
But even if it is diet alone, it’s not by an overwhelming amount either. What gives? If swaying really works, if diet and lifestyle factors are altering the rate at which boys and girls are conceived, wouldn’t we expect to see WAY different numbers in poor countries than in rich ones? If all diet can give is a .01 difference, what’s the point?
Let’s take a closer look at a couple of the studies in question that do not seem to support the TWH in humans. (if you’d like a brief refresher about what the Trivers Willard Hypothesis is, I have an essay about that here: http://genderdreaming.com/forum/gend...ypothesis.html)
(Dutch hunger winter) http://rspb.royalsocietypublishing.o...e2=tf_ipsecsha
(Cuba) http://aje.oxfordjournals.org/conten....full.pdf+html
Wow not looking good for TWH, is it? These studies actually seemed to show the opposite of what we’d expect to see if TWH were true. But I actually believe these studies SUPPORT TW.
Scientists have an unfortunate habit of viewing human beings as lab rats – lab rats eat only what the researcher feeds them, breed when and how the researcher wants them to, it’s all a very controlled situation without a lot of variables going on. But the real world is NOT like that and humans are NOT lab rats. Humans are actors (not actors like George Clooney, I mean beings who “act” on their environment) who control their own lives, bodies, and choices to as great an extent as they are able to, both consciously by altering behaviors, and subconsciously as the body itself alters the way in which it functions in response to environmental signals.
First of all, when food resources are really very scarce, many women will stop menstruating all together. In the Dutch Hunger Winter study, they have data that indicates !!!!! 50% !!!!!! of all women stopped menstruating during that time period.
If you’ll recall, the Fertility Theory rests on the premise that people who are lower in fertility have more girls and people who are highly fertile have more boys. The Fertility Theory also takes into account the biological fact that when food becomes scarce, people stop ovulating (or at least at a drastically reduced rate, cycling maybe 2-3 times a year if that even.) Less food, fewer ovulations, more girls conceived.
When resources grow scarce across a population, it is not that all the resources were thrown in a pot and divvied up evenly. Some people continue to have more and/or better quality than others at least for some period of time after the famine started – it’s not like a starting pistol went off and said, “begin your famine NOW!! and everyone immediately stopped eating. The division of resources is not equitable, we are not rats in a lab being fed carefully measured Purina rat chow by white-coated lab techs. Life is not fair and some people have and continue to have more than others even in times of famine.
Additionally, we didn’t all start off from the same place to begin with; because we are people and not lab rats, we are genetically diverse and have eaten a wide array of foods for our whole lives. Even when famine strikes, not everyone is created equal – some continue to have access to adequate nutrients, some are able to keep ovulating even on less food due to genetic factors (this may be the evolutionary explanation for PCOS, as a matter of fact), while others had an oversupply of nutrients (body fat) to rely on to begin with and thus could lose a lot of weight before their menstrual cycle ceased.
I believe that Mother Nature has come up with a very elegant way to ensure both boys and girls are always conceived in roughly equal numbers regardless of the overall conditions/food supply. In times of famine, the people who may have been predisposed to having girls to begin with in better times, decline in condition and stop ovulating, some people who were in ok condition, decline and begin having girls, but many, many others just keep right on chugging away staying fully fertile and having boys. Perhaps genetically they aren’t affected by deprivation as much, perhaps they had ample stores of nutrients to fall back on, perhaps they were getting food resources from other places, or some combination of all three. The overall number of births across the population declines, but the ratio of male to female conceptions stays roughly the same.
In the Dutch Hunger Winter study, 50% of women of childbearing age could not get pregnant to begin with. Those people were by definition in the worst condition, at least in terms of fertility, and probably also had less food than those women who didn’t stop ovulating. And I’ll wager that even among those who didn’t stop ovulating, their cycles got longer, their luteal phases shorter, they became less able to get and stay pregnant even when ovulation continued in some fashion. What the findings of the Dutch Hunger Winter REALLY are saying is, “in times of famine, it is most likely that those who are able to continue ovulating, get and stay pregnant are also in the best condition and most likely to conceive boys”. This is completely IN SUPPORT of the Trivers Willard Hypothesis. The researchers put a different spin on it but that is due to their own preconceptions about humans being lab rat equivalents and not the data in and of itself.
Mother Nature is no dummy; if a lack of nutrients could ever overwhelmingly cause an entire population of individuals to start cranking out only or mostly girls, the entire species would have died out long ago. There simply has to be a mechanism that keeps the gender ratio fairly close to equal even in times of deprivation or we would already have proven TW true beyond a shadow of a doubt. That this mechanism exists doesn’t mean TW is not true, it means that the human body is a marvelous thing. It can absolutely be the case that TW is true but that simultaneously there is a mechanism (or more than one) that keeps gender ratio across a population at about 50-50 anyway.
Secondly, LOTS of habits and lifestyle tendencies change when times are tough – not just eating habits. In the Cuba study, it’s mentioned that people who were smoking a lot, smoked a lot less during this period of famine. I suspect that they drank less and had less coffee as well. Given that we know based on our experiences on the site, that coffee, smoking, and alcohol all sway pink, it is entirely possible to me that cutting back on things that sway pink at the same time food was somewhat restricted could easily have swayed blue for some people even as they were eating less calories than they had been. Gender ratio is multifactoral; we see this firsthand on Gender Dreaming all the time. It is NEVER just diet, it's diet plus coffee and smoking and the number of attempts you have and if you played sports in high school and all sorts of things possibly dating back as far as when you were an egg developing in your mother's ovary in your grandmother's womb.
Additionally everything that was true of the Dutch Hunger Winter study (that at least some people were still able to have access to better quality nutrients and thus could have stayed fertile and in fact even boy friendly while others stopped ovulating and that this could explain how Trivers Willard can both be true and yet the gender ratio stays constant at 50-50 even in times of famine) is also true in Cuba. If not even more so, since famines under totalitarian regimes (particularly tropical paradises) tend to be much less fairly applied to all than a nation in winter, in wartime. There is no doubt in my mind that some Cubans had greater or lesser access to food than others did and it only makes sense that these people would be the most likely to get pregnant or even to feel comfortable enough in the situation to want to.
That seems another thing that scientists conveniently forget - women (and men) are not lab rats who compulsively breed when they come into season. People have the knowledge that sex = babies and can take precautions to prevent that from happening as they so desire. And people do. They don't have sex, they pull out, they do other things besides intercourse, they avoid their fertile windows. So just by virtue of having gotten pregnant during hard times - this is not a randomly selected group of people we are talking about here. There were likely choices made by the majority of these women to conceive a baby despite the lack of food, despite the chaos and insecurity they were living in. Multiple factors weeded some people out of the “let’s have a baby” group creating a narrower and narrower funnel that fundamentally alters the nature of the test group.
As we already discussed (and witnessed firsthand on Gender Dreaming), many women will stop ovulation even with a fairly small restriction in calories and/or increase in exercise. Right away we do not have a randomly selected group. We are dealing ONLY with the group of women who can get pregnant even in times of widespread famine. Beyond that, we are dealing only with the group of women who WANT TO. Now, maybe not all these pregnancies were voluntary or planned, but since people do have the ability to avoid pregnancy by not having sex or by taking precautions (both before and after conception occurred...people do have their ways) again, the people who conceived and carried a baby to term are not a randomly selected group of lab rats who breed because of instinct when they come into season. We are possibly selecting not only for higher fertility overall, but also for higher sex drive, higher social standing and/or a more secure position in society (who brings a new life into a war zone or totalitarian dictatorship unless you’re at least somewhat secure in your position?), confidence that you can care for yourself while pregnant and can care for a newborn/toddler - via social connections, stored resources, faith in your own abilities. People surviving in a famine are not taking part in a scientific study. They were real people, real lives, real choices, and some of them chose to have babies and others did not or could not. This makes a real difference.
The women who had babies during the Dutch Hunger Winter and the Special Period in Cuba were not lab rats carefully selected, fed, and bred by researchers. Their choices mattered and Trivers Willard actually predicts that those choices would have an effect on the gender of their babies but it does NOT predict that these choices will necessarily be reflected in the gender ratio across an entire nation because every individual is in a slightly different, unique set of circumstances and what is declining condition for one person may not be for another.
Our results and a lot of other studies besides show that the Trivers Willard approach is working. Sometimes it’s necessary to set aside the conclusions of researchers to take a deeper look at the data in a study to see if it’s really saying what the researchers claim.
