Engineers Have More Sons, Nurses More Daughters 668
Bifurcati writes "While it might be irrelevant for many /.ers, a recent study has shown that people in stereotypically male professions (engineering, IT, mathematics, etc) are more likely to have sons than daughters, while nurses, therapists and teachers tend to produce more girls. Based on independent survey data, engineering types produce 140 boys to every 100 girls, while nurses and the like produce 135 girls to 100 boys. The explanation is unclear, but it might have interesting long-term social implications. A more detailed summary of the journal article is available on Illuminating Science."
diet can affect gender... (Score:5, Funny)
Re:diet can affect gender... (Score:2)
Re:diet can affect gender... (Score:4, Funny)
Interestingly, so can dominance-submission of the father. The theory is that dominance or submision will be passed on to the child either through genetic or envrionmental factors. Result is that a dominant male child will get around a lot and have many kids whilst a submissive male will not get many mates. Therefore, if you're dominant, best to have a male child and if your low-status, best have a girl as she's going to get laid anyway.
Relating it to the story? Engineers are clearly high status individuals. So get out there, boys.
Re:diet can affect gender... (Score:2, Insightful)
What do you mean by "Dominance" or "Submissive" in your passage? Socio-economics? Family Politics? parenting style?
Im not so sure all the shit that applies to apes in the wild applies to humans -- we have a much larger social context that doesnt always sync with purely animal instincts.
Re:diet can affect gender... (Score:4, Insightful)
Our "animal" natures just have nice neat social labels... which makes them seem more "human"
The *only* thing that separates us from the animals is our self recognition... and even then, arguably, only marginally.
Re:diet can affect gender... (Score:4, Funny)
I'm 98 to 99.4 percent monkey, you insensitive clod!
Re:diet can affect gender... (Score:3, Insightful)
Only problem is were talking about humans here, who have quaint little institutions like marriage, bigammy and child maintainance laws and the like.
One - these institutions have been formalized for a couple of thousand years and even then not consistently, and even then only in a geographically limited areas or the globe. It's reasonable to hypothesize that this will not have yet over-ridden a million years of accumumlated genetic tendancies, and the correlation bears this out.
Two - are these institu
Re:diet can affect gender... (Score:5, Funny)
Or does it cause conditions such as XX males and XY females?
Re:diet can affect gender... (Score:5, Informative)
Environmental factors can play a strong role, and might have been involved in the latter case. Excessive androgens produced by the mother can lead to degrees of virilization of the fetus; other factors may help cause androgen insensitivity and thus feminization. Gender isn't so clear cut; it just tends to migrate to one extreme or the other because that's genetically advantageous, and the Y chromosome usually acts as a carrier for the genes that activate virilization.
As for what's causing the "engineer shift", that's a really good question... that's a pretty darn big correlation that the article described.
Re:diet can affect gender... (Score:3, Interesting)
Re:diet can affect gender... (Score:3, Interesting)
In certain animals (including, perhaps, humans), the quality of diet has a correlation with the gender of offspring.
Or, to put it bluntly: Healthier females have more sons.
The explanation behind this is simple: Females have an excellent chance of breeding, regardless of health. In many species, however, the healthier males have a higher chance of breeding than weaker males. Evolution thus favors healthy females to have male children, and weaker females to have female children.
Re:diet can affect gender... (Score:5, Interesting)
Re:diet can affect gender... (Score:3, Interesting)
That only holds for a bell curve. See my sig and think on it.
Finally I know (Score:5, Funny)
Irresponsible statistics (Score:5, Insightful)
Irresponsible Post. (Score:2, Informative)
Wrong. (Score:3, Informative)
Re:Wrong. (Score:5, Informative)
From the second: They're very cautious about interpreting the cause of their results, and what conclusions could be drawn.
Read past the first line teaser. The meat of the article isn't nearly as bad as one would like to pretend.
Not Wrong - Look at the bloody context (Score:5, Informative)
Re:Not Wrong - Look at the bloody context (Score:3, Insightful)
wrong yourself (Score:2, Insightful)
yeah, the above quotation from TFA destroys any reasonable claim to validity this study purports...in other words, this study/article/post is bullshit
Just more silly science. If they wanted to make this claim legitamitly, t
Correlation is fine here. (Score:2)
Re:Correlation is fine here. (Score:4, Funny)
However, solving equations of course favours Y chromosomes. That's because you always solve after X, so you have its actual value and therefore can eliminate it. Eliminating X of course doesn't affect sperms with an Y chromosome (because it doesn't have an X to eliminate), but only sperms with an X chromosome (after all, x is exactly what you eliminate).
SCNR
Re:Irresponsible statistics (Score:5, Funny)
"I'm a science wenie and need to get out more."
The article doesn't draw conclusions. Its just an interesting set of data.
Re:Irresponsible statistics (Score:3, Informative)
That looks like a conclusion to me. Or were you talking about the scientifical paper itself?
Re:Irresponsible statistics (Score:5, Interesting)
* How were the groupings into "masculine" and "feminine" professions done? Is this reasonable, and did they truly choose the most "obvious" masculine and feminine professions to include?
* Do these groupings span the dataset, or are some (possibly most) professions excluded as "neutral"?
* What is the breakdown by profession for all professions, not just the included groups?
* Most importantly, was the selection of the "masculine" and "feminine" professions determined BEFORE or AFTER the data was collected?
My concern here is that they started with a dataset for chilbirth for all professions (probably on a fairly small dataset). They noticed some professions skewed one way, some another. They noticed that some of the professions skewing male were "masculine" and some skewing female were "feminine" and called it a conclusion, sweeping all the other anomalites in their dataset under the rug. Hey, presto! Conclusion!
Fact: The general benchmark for "statistical significance" is 95% confidence that the data cannot be explained as a random phenomenon.
Experiment: Create 20 hypothetical correlations to test for on a completely random dataset. On average, you should find one in twenty hits the 95% confidence mark.
Intellectually dishonest followup: Publish your one statistically significant result with great fanfare. Bury the othe 19 in a footnote, if you mention them at all.
Step 3: Profit!
Re:Irresponsible statistics (Score:3, Insightful)
Repeat after me, "Lack of causality does not make the correlation insignificant."
Irresponsible conversation (Score:5, Funny)
Repeat after me, "I'm a bit daft, and I like to think others will repeat silly things I say from time to time."
Now, go have a beer.
Re:Irresponsible statistics (Score:2)
I've heard that before. But correlation does imply correlation. The data itself seems compelling to me with the skew of 35 - 40 births for some subsets of the population vs the average. I don't have the data in front of me, but I believe that the female infanticide in China skews the male/female ratio less than these data.
One could theorize that engineers and nurses may be more successful and strongly stereotypical of their respective genders. E
Re:Irresponsible statistics (Score:3, Interesting)
Oh no it doesn't. And becide how do you know which way it works?
Perhaps having boys causes parents to go into engineering?
Or more likely some unknown 3rd factor causes both thing: boys and engineering. So there would be not causation between engineering and boys. (Meaning going into engineering would be useless.)
There are so many junk science reports that show correlation, but never show which way the causation goes. Which is the cause and
Not quite true. (Score:2)
In the mathematical sense (if A then {always} B) that's true.
In the common meaning of imply ("If A is correlated with B and B follows A then A MAY cause B.") it sure does.
A strong correlation hints that there's a causative mechanism - either the later-appearing item occurring as fallout of the observed earlier-appearing item by some chain of influences, or both of them being the result of such chains from some other common precursor.
Doesn't PROVE
Re:Irresponsible statistics (Score:3, Informative)
And the Internet as a whole is a terrific place for posting as fact misreadings of misinterpretations of things people don't say. (No, not you.)
The original paper [sciencedirect.com], which was a study based on a few thousand people, was looking at extreme male-brainedness in autism. They picked out profession as an indicator of male-brainedness. The data for sex of the offspring was available only one year (1994) of the data they had.
They also selected th
Re:Irresponsible statistics (Score:3, Interesting)
Not strictly true.
For starters, X and Y bearing sperm are affected differently by envrionmental factors (such as pH) which has been used in vitro to strongly bias fertilization toward one sex or the other. The female provides the environment (including pH) in which the sperm swim.
There are plenty of other ways a woman's body COULD bias the outcome. Anitbodies - leading to reduced sperm mobility or higher likelyhood of spontaneou
Re:Irresponsible statistics (Score:3, Informative)
Don't recall exactly - I've seen it several places (including Animal Planet).
But a web search on "lizard virgin birth" quickly turned up a bunch.
It's the Whiptail Lizard. There are about 15 species of it that reproduce exclusively by parthenogenesis - the largest vertibrates to do so.
Apparently hybridization of two other lizard species sometimes results in a f
Re:Irresponsible statistics (Score:3, Informative)
However, these subspecies of fish generally do not last very long. Parthenogenesis is a good short term strategy as it allows higher rates of reproduction than sex. However, once you get into an evolutionary timescale these parthenogenic fish are not well eq
Re:Irresponsible statistics (Score:3, Informative)
Re:Irresponsible statistics (Score:2)
We have a girl.
Environmental factors and sex at birth ratio (Score:3, Insightful)
This is simply not true except in the most simplistic sense. Sperm counts (according to the wikipedia) have a normal range of 20 to 180 million per millileter. There are countless sperm carrying both the X and Y chromosone vying for the prize.
There are subtle differences between X and Y bearing sperm in robustness and mobility, IIRC; it is possible that the male can influence conception sex by producing sperm of each type that ar
Causality (Score:5, Insightful)
I think it's far more likely that it's not what job you're doing, it's what job you tend to want to do.
It IS what job you're doing... (Score:4, Interesting)
We have two groups of children: One group has a parent who is in a "male" profession, like engineering, and the other has a parent in a "female" profession, like nursing.
What is far more likely to be true of a child with a parent who is in a female profession as opposed to a child with a parent in a male profession?
They're more likely to have a mother who works.
Seems pretty obvious to me: Working moms are more likely to have girls. Might have something to do with Y-chromosome sperm being more fragile than X-chromosome sperm. (That's been demonstrated elsewehre.)
World Domination! (Score:5, Funny)
Oh wait, according to my calculations the probability of me getting laid is 3x10^-8
Simple explanation (Score:5, Funny)
Re:Simple explanation (Score:2, Funny)
Re:Simple explanation (Score:5, Funny)
--- JOKE --->
0
you ->
/ \
Just to spell it out for _It doesn't come easy_, this is a a joke flying right over your head.
Ob. Troy McClure (Score:5, Funny)
Re:Simple explanation (Score:5, Funny)
Needs a lesson in genetics. (Score:5, Informative)
What does this have to do with the father? What does this have to do with which sperm gets into the egg?
Re:Needs a lesson in genetics. (Score:2)
And that's ignoring the fact that conception is just the first step. There's no reason that the conditions in the womb can't provide for higher survival rates based on sex.
Re:Needs a lesson in genetics. (Score:2)
Re:Needs a lesson in genetics. (Score:3, Informative)
What does this have to do with the father? What does this have to do with which sperm gets into the egg?
While I agree with you that this is total crap, it is concievable that some environmental factor (e.g estrogen level in a woman, diet, whatever) could favor sperm carrying Y chromosomes over those carrying X chromosome, or visa versa. So, while it may not have anything to do with what the male delivers, it might affect what portion of that delivery are mos
Lies, Damned Lies, and Statistics. (Score:3, Funny)
Re:Lies, Damned Lies, and Statistics. (Score:3, Funny)
Re:Lies, Damned Lies, and Statistics. (Score:2)
And think about your poor son! The first half of his life he'd be teased by his sisters(ss) friends, the second half he'd have all the tang he wants right there in front of him during sleep overs, but would be too scared of girls
Yeah, well it's gonna get messy for me. (Score:5, Funny)
correlation and causations (Score:4, Insightful)
I mean, how would somebodies profession really determine his/her childs' sex? I'm sure that mining other datasets would lead to similar 'interesting' ratios/facts.
As has been mentioned on
Re:correlation and causations (Score:2)
Two things
1) Yes, we all know about correlation and causation
2) This is statistically interesting. It is interesting enough to warrant further study, which is probably why the silly report was written in the first place.
Side Note: I'm a sysAdmin, my Ex was a teacher, we had 1 boy and two girls (Boy first, followed by two girls). I guess teachers/nurses are better at picking their offspring than sysAdmins!
Re:correlation and causations (Score:2)
Actually, I'd say the numbers they claim are astonishing. A p-value would have been nice, but with any estimate of the variance of sex ratios that seems remotely plausible to me, the difference they're reporting is enormous.
Re:correlation and causations (Score:2)
Most people don't chose their careers at random -- they gravitate in to those careers which are a best fit for their natural talents. It seems likely that there is a genetic basis for a person's aptitudes. It's entirely plausible to speculate that the genetic variations which give a person the personality and aptitudes to seek out an engineering career could also affect their reproductive systems.
Re:correlation and causations (Score:4, Insightful)
For the "masculine couple" (please note that the following are not equal in probability!):
BOY, stop
GIRL, BOY, stop
GIRL, GIRL, BOY, stop
etc.
A similar (substituting BOY and GIRL) sequence can be made for the "feminine" couple.
It is easy to see how this would lead to more BOYS or GIRLS in each respective case (on average).
This is one possible explanation of cause.
Re:correlation and causations (Score:3, Informative)
Re:correlation and causations (Score:5, Insightful)
Not so. Assuming you have a 50-50 chance of it being a boy or a girl, you will end up with 50% boys and 50% girls no matter what contortions you go through to try to influence the outcome.
Look at it another way: pretend these are coin flips rather than childbirths. Your suggestion (that you can alter the odds by when you choose to stop trying) is equivalent to saying that you can bias to heads or tails by deciding when you stop flipping the coin. And, of course, that isn't true -- no matter how many trials you perform or in what order, a fair coin will (on average) deliver 50% heads and 50% tails. One more 50-50 flip won't in any way alter the expected outcome.
It's exactly the same way with childbirth. The first child (we would expect) would be 50% likely to be a boy. The second would be 50% likely to be a boy. The third would be 50% likely to be a boy, and so on ad infinitum. Adding another trial (childbirth) onto the end of the sequence does not change the odds, and on average you would end up with 50% boys and 50% girls.
Of course, this research shows that that naive assumption isn't true, and apparently something is altering the odds. We just don't yet know what.
(And, amusingly enough, I'm to find out my baby's gender in two days. Evidently it's more likely to be a boy...)
my bit of anecdotal evidence (Score:2, Informative)
What about those couples, like myself, who have an IT guy and a nurse (to be)?
Re:my bit of anecdotal evidence (Score:2)
Explanation is bullshit (Score:2, Informative)
The gender is determined by the chromosome set when sperm and egg fusion. That has nothing to do with testosterone levels later experienced in the womb.
Explanation is worthy of investigation (Score:3, Insightful)
I'm therefore not at all surprised by the result that couples are more likely than chance to have "more of the same" sex children.
I also would not discount the testosterone theory out of hand.
Re:Explanation is bullshit (Score:2)
Re:Explanation is bullshit (Score:2)
But please don't make the mistake to try to find a 'reason' to it. Evolution is just some statistics at work, there is not somebody desig
And I married a nurse (Score:5, Funny)
Hopefully (we dont have children yet), I'll have a healthy boy or girl, who will take great care of me AND my source code in my very old age.
Re:And I married a nurse (Score:2)
This gives a whole new meaning to "legacy software"!
Re:And I married a nurse (Score:3, Funny)
Shettles Method (Score:5, Interesting)
There are proponents of different techniques that supposedly let you choose the sex of your child. One interesting technique is called the Shettles Method [google.com]. One family that I know swears by this method. They are four for four in getting it to work.
At any rate, perhaps different personalities or lifestyle conditions between engineers and nurses would help to explain this data - if indeed there is any credence to Shettles or similar methods.
Re:Shettles Method (Score:3, Insightful)
Either that or they're the the one out of sixteen who randomly get four children of sexes desired.
Aaagh. (Score:2, Funny)
My statistics professors are currently:
a) rolling in their graves
b) suffering cranial detonations
c) weeping like Baby Jesus
Re:Aaagh. (Score:2)
Re:Aaagh. (Score:2)
Bull Pucky (Score:2, Insightful)
Among us there are five kids, and every single one of them is a girl. (They each have two, I have one)
Obviously we weren't included in the survey.
And when I worked at Atari, the Engineers and game developers were convinced that CRTs kill male sperm because most of them had baby girls, in fact I believe it was over 90% girls.
I think someones just yanking our chain.
Raydude
Oh, yeah... (Score:3, Funny)
We know what these psychologists were doing in biology class, and it wasn't paying attention to what was being taught.
Do adopted kids count? (Score:2)
Re:Do adopted kids count? (Score:2)
The survey data does not distinguish between adopted and biological children (those questions weren't asked) so it is possible that the effect is entirely one of choice in adopted cases, or at least that it is a contributing factor.
Easy explanation! (Score:5, Funny)
Summary of the actual article (Score:5, Insightful)
The actual article (Journal of Theoretical Biology, 233, p589-599 "Engineers have more sons, nurses have more daughters: an evolutionary psychological extension of Baron-Cohen's extreme male brain theory of autism" by Satoshi Kanazawa [lse.ac.uk] and Griet Vandermassen [ugent.be] and available through Elsevier's Science Direct [sciencedirect.com]) came out in December 2004 an is available online for those whose institutions subscribe, notes the following correlations:
This is based on survey data from US professions of around 1500 people. Only some of the professions are categorized as "systemizing" and "empathizing" so presumably the sample size is much smaller than that . The sample size isn't listed directly in the article but it appears to be about 20% of the 1500 with at least one parent so categorized profession, for around 300 people or so. Most professions are neutral in the "systematizing/empathizing" continuum, apparently.
Amoung those with "systemizing occupations" had regression coefficients of
From the classification of professions:
Systemizing occupations
Empathizing occupations
Presumably other professions are regarded as neutral in this spectrum.
It's probably the radiation... (Score:2)
Nature at work (Score:2)
Well, it didn't sound too scientific, but it made sense to me. Since then, every statistics like that I was able to explain with my grandmother's theory. Face the facts guys, you might have got yourselves some wives to pretend
..huh? when why did... (Score:2)
doesnt add up to me.
Conclusion is totally incorrect (Score:2)
The Sunday Times quoted a specialist in evolutionary psychology as saying it could be because the children of "systemiser" parents appeared to encounter more testosterone in the womb, making their gender more likely to be male.
Yeah, but there is no evidence to support that.
Instead, it could be that engineers, who are obviously well educated (and thus the head of the family) and more likely to be men, favor boys. and so if the first kid is a boy
Oh man (Score:2)
Ahahahah!!! Oh, too funny. I almost busted up at a very inopportune time (what I get for slashdotting when I shouldn't).
Dammit, I'm an outlier. (Score:2)
I don't know what upsets me worse, that I must not be a manly enough engineering type, or that I am unnecessarily skewing the statistics.
:)
babies sex can be influenced. (Score:4, Interesting)
There is no doubt that a babies sex can be influenced by a number of criteria. Male sperm tends to be faster, but live shorter lives. Female sperm is hardier, but slow. So a women who is slightly acidic or base will tend to kill the male sperm leaving female sperm. Likewise, if traditional sex prevails (male on top) with a laying around afterwards, then male has better chance (shorter distance, as gravity helps carry the sperm further up (BTW, so does a women's orgasm). But if women on top, then sperm has further to go, so more likely that female sperm wins.
So why relevant? Nurses, teachers, etc have a healthier attitude about sex. More likely the women are on top (or at least have a varied sex life). Girl wins.
Engineers are more conservative, so more likely to be on top. Boy wins.
Re:babies sex can be influenced. (Score:5, Funny)
The reverse (Score:3, Interesting)
The exact same thing has been demonstrated in many animals with the interpretation that we are unconsciously trying to fix the perceived sex ratio.
It probably already has had interesting, long-term (Score:2)
I knew it! (Score:2)
Nurses stand up, Engineers sit (Score:3, Insightful)
Re:If a nurse and engineer marry and have a child. (Score:5, Funny)
Do you mean "comes out" as in born or "comes out" as in closet?
Re:Balance (Score:3, Funny)
So clearly I need to spend some more time at a computer if we're ever going to have a boy... oh, wait.
I think the real reason is some engineers even manage to scare off their own X sperm.
Re:I'm an engineer married to an RN (Score:2)
Re:Windows - favors Girls, Linux/UNIX - favors boy (Score:3, Funny)
Re:Hermaphrodism (Score:2)
My _three_ brothers and I (also male) are doing fine, thanks.
Re:Oh really?! (Score:2)
http://www.cia.gov/cia/publications/factbook/ [cia.gov]
Re:Case of /. ing (Score:3, Insightful)
Short people, if they switch to being tall, can improve their chances of having tall children.
Engineers aren't in their profession by accidentally not becoming nurses or teacher