Slashdot Mirror
A New Explanation For the Plight of Winter Babies
Ant passes along a Wall Street Journal report on research that turned up a new explanation for the lifelong challenges experienced by winter babies. "Children born in the winter months already have a few strikes against them. Study after study has shown that they test poorly, don't get as far in school, earn less, are less healthy, and don't live as long as children born at other times of year. Researchers have spent years documenting the effect and trying to understand it... A key assumption of much of that research is that the backgrounds of children born in the winter are the same as the backgrounds of children born at other times of the year. ... [Economist] Mr. Hungerman was doing research on sibling behavior when he noticed that children in the same families tend to be born at the same time of year. Meanwhile, Ms. Buckles was examining the economic factors that lead to multiple births, and coming across what looked like a relationship between mothers' education levels and when children were born." Here's a chart in which the effect — small but significant — jumps out unmistakeably.
Of course the difference jumps out. The chart was deliberately designed to make the change jump out by not using 0 as the origin of the Y axis.
This is a very common technique for making a difference look a lot larger than it actually is.
The cake is a pie
People have been debating this explanation for decades, and studies are all over the map. It'd be more accurate to say that there is yet another new study on the subject of the relationship between season-of-birth correlates and socioeconomic factors, this one claiming that the relationship is in fact significant. There's a bunch more studies if you'd like.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
There's a tendency for promiscuous, uneducated teenagers to have unprotected sex during springtime and early summer. It's always easy to say this, but, duh...
Any measurement made requires two peices of information: the measurement and the uncertainty associated with that measurement. To present data as though its known with 100% certainty is misleading and incorrect. It seems pendantic to worry about uncertainty, but when you're dealing with small effects on the order of less than one percent, if the error bars are +/-2.5%, then it's absolutely incorrect to refer to the result as "jumping out".
The difference is extremely small, but one would expect that people getting pregnant because of a one-night-stand or a whim is both higher among the uneducated, unmarried, and also higher during spring when many people's hormones tend to go into higher gear. People who are more in control of their emotions and actions tend to be more educated and are (at least somewhat) less likely to sleep with half the town during spring break.
Of course, the correlations I mention above don't necessarily have to be very large, but probably large enough to affect the statistics by a tenth of a percent.
doctoral thesis claims their "significant" find is "significant". sigh.
You could do better... if you were born in June.
If you count backward from January, that puts conception around April/May. Right around graduation. So if you suppose the poor and less educated would be getting married and starting a family instead of getting ready for college, that might explain some of it.
It would probably be just as interesting to track the birth rates correlated to surges in beer and Jagermeister sales.
That's our life, the big wheel of shit. - The Fat Man, Blue Tango Salvage
I don't think it means you will present all the aforementioned characteristics. So you could still die young!
There is a secondary bump around September in each of these charts - it's much smaller but consistent every year. Fascinating.
The real causative in winter babies is that babies born under winter's astrological signs have shorter lifelines.
Your grammar?
I see the explanation in the fact that married and educated women have sex with their man only once a year during their holiday in July/August. :)
I wonder if all the data comes from the North Hemisphere? What happens in the south?
I was born in late December and stopped once I got my Bachelor's (but with a GPA significantly higher than 3.4) to pay off my student loans. I paid off the last of the loans within four years after graduation and have been continuously employed since. But these are just individual data points, and the slashdot readership is by no means a random sample of the population in any case.
Cut that out, or I will ship you to Norilsk in a box.
I know the feeling. Born in January, running a 94% average for my entire school career.
Don't it feel good to be a misfit? (And to all the grammer Nazi's, that was intentional.)
Funny may not give karma, but +5 Informative never made anyone snort coffee out their nose.
The age cutoff for entry to kindergarten seems to cycle around mid-September, but varies quite a bit from state to state. But in general, a kid born in the winter will have to wait longer to start school.
Anyone else picture this guy screaming, "Get in my belly!!"?
Dumb chicks put out in spring when they are horny.
Smart chicks put out when the crops are mature and it's clear there will be enough resources to feed another mouth.
It's amazing how much human behavior is hard wired into us.
We have more than enough evidence to conclude that
kids do better in intact 2-parent families.
Casting tradition aside isn't without a cost.
Looks like someone couldn't see the forest for the trees. All these years of study before someone figured out that there was a releation to the intelegence/eduction/etc of parents. Ugg...
Yea, it just evolved that way and despite a century of grocery stores and not getting your food from the farm directly, it has not evolved back away from it. Go figure.
> Unwed? What is this, 1950?
Statistically, the marital status of the parents is highly relevant to the child's prospects. Children whose parents are married to one another from prior to conception clear through until the child is an adult get on average much better grades in school, are significantly more likely to consistently hold down jobs as adults, make more money on average, are significantly less likely to have a criminal record, are less likely to be smokers, and so on and so forth. These are quite strong correlations.
Now, correlation is not causation. It's possible that the parent's strong marriage does not *cause* the child's good prospects and performance, but rather that both are caused by some of the same socioeconomic factors. But it's still very much relevant in a statistical study like this.
Cut that out, or I will ship you to Norilsk in a box.
It's a pity...if only you'd been born in May, you'd have been getting a 96% average!
The cake is a pie
The zodiac holds the most obvious relationship. Everyone knows Geminis are smarter than Aquarius folk. It's in the stars.
Perhaps if you were born in May, you'd understand about significant, but small statistical differences and how they relate to the experience of individuals.
Or to put it in more real world terms, you are like a woman reading an article saying "statistically speaking, the average man is four inches taller than the average woman" and saying "what crap! I'm taller than a lot of men I know!"
The cake is a pie
I was born in December and pursuing double masters with GPA of 3.4 is it really bad?
I was born in June, and received a Ph.D by the time I was 27, with a 3.95 GPA. Luckily for me, part of that Ph.D training involved learning that the word data is not the plural of anecdote.
It's a good thing, too, because your comment might otherwise serve as the first brick in the foundation of my claim that summer babies are caustic and monumental shitheads that seem to spend their free time in pissing matches.
It might make an interesting study to compare the success of kids with "late" birthdays who started on-time/early versus those who had to wait an extra year.
I thought I'd heard of a similar study where kids with winter birth dates excelled at sports because they tended to miss cut-off dates for teams, and therefore were older, larger, faster, and more mature than the kids they were teamed with each year. This leads to them getting more time handling the ball as they grow up.
I was born in August of 1995 and I am pursuing a PhD in Rocket Science and another in Brain Surgery. My GPA is a 4.22.
Children who are born to mothers that are not married tend to have less complete support systems and fewer financial resources. Even the best single mother can only do so much in 24 hours. She can't do it all. As a result the children can suffer. Children that grow up with parents who have a healthy relationship have an advantage of those who don't.
There's less social stigma attached to it today, but the results are the same.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
suppose educated women (and education strongly correlates wit income and wealth) "know" htat babies are supposed to be born in the spirng.....
this would rduce the whole thing to a cultural artifact: well to do parents tell thier kids to have a spring baby, and so it goes...
Now, correlation is not causation. It's possible that the parent's strong marriage does not *cause* the child's good prospects and performance, but rather that both are caused by some of the same socioeconomic factors
I like the idea that it's actually a reverse correlation- that stupid children with poor prospects and bad grades cause their parents' divorces.
Sigh. Correlation means one of three things with regard to causation. In this case those are:
a) being born in the winter causes increased risk of health and education problems for the baby
b) the baby's increased risk of health and education problems causes him or her to be born in the winter (clearly ridiculous)
c) a third factor causes the baby to both be born in the winter and have increased risk of health and education problems.
The correlation between birth month and risk of health and education problems has been observed. This study is pointing out that the direct causative option (a) is probably not true since they have found possible third factors (c) that appear to influence birth month and are known to have an effect on the risk of health and education problems.
In other words, the study is saying, with actual data and without the childish, misunderstood slogans, the same thing you are - birth month does not cause increased risk of health and education problems.
Showing correlation is required for establishing a causative link between two observations so no, correlation studies do not "need to die." It would be nice if people (including you) understood them a little better though.
I was born in June and finished my PhD while maintaining a GPA of 4.0 throughout grad school.
We've got two anecdotes... does that mean we have data now? ;)
I have a different take, July/August school is out, March/April Prom and spring break. In other words, I think teenage pregnancies are hiding any thing else interesting in this kind of data.
I was born in June, and received a Ph.D by the time I was 27, with a 3.95 GPA. Luckily for me, part of that Ph.D training involved learning that the word data is not the plural of anecdote.
Bah.
Everyone knows Geminis are a smart lot (I'm one, too) so your accomplishments, while impressive, shouldn't be considered surprising. As for the OP, Sagittarius is a fire sign, so if he's anything like the Sagittarians I've known, he's probably dumb as a brick, but has the capacity to work harder than everyone else.
Whether the above is science, myth, anecdote or a case of "it's on the internet so it must be true", you be the judge. ;-)
ahhaha
I've been reading the discussion and getting it completely backwards. Damn people not specifying their hemisphere (I was born in June, but I'm a "winter baby").
Yeah. Would you choose a neurosurgeon who pokes around people's brains in his spare time? I wouldn't.
Just to give an idea how silly individual data points are, here's what the data says in English:
People who are born in January will get, on average, one month less education.
Babies who are born in January are 10% more likely to have a teenager for a parent. (Note teenager means under 20)
Babies who are born in January are 3% more likely to be born to an unwed mother.
Interesting statistics, but the differences too small to really matter when comparing individuals. The fact that all of these measures aren't showing direct correlation with success but only correlations with other factors that correlate with success, any concern about when individuals are born is pointless. This study says little or nothing about what advantages a rich kid with married parents who is born in May might have over a rich kid with married parents who is born in January.
The cake is a pie
Of course the larger correlation was also observed, but apparently ignored in the summary:
The same pattern kept turning up: The percentage of children born to unwed mothers, teenage mothers and mothers who hadn't completed high school kept peaking in January every year. Over the 13-year period, for example, 13.2% of January births were to teen mothers, compared with 12% in May -- a small but statistically significant difference, they say.
Spring break, and Back to school seem to correlate as well as anything, and both seem to correlate to higher instance of teen mothers. The numbers of teen mothers probably swamp any other significance.
Sig Battery depleted. Reverting to safe mode.
People who plan their pregnancies are more likely to be educated, married, and not teenagers. People who plan pregnancies are not likely to try to target November - January, because it's cold and they won't want their babies birth close to Christmas and Thanksgiving.
Sagittarius here, 2 bros and parents all born in spring or summer. I'm the only one who attended college, earned my BS in exactly 36 months. Grades weren't great(2.7GPA) but like I said 36 months, while working 3rd shift 25+ hr/wk merchandising in grocery stores. Shortly after I graduated I was passed over and my employers hired a gal w/ better grades and NO industry experience. That fall('94) I went to work for a brokerage house selling Muni Bonds, 3 months later I found out why my boss transferred from Orange County. Never had a corporate job since, their contract work pays way to good, work when I feel like it and no office politics. Win-win-win. However, I will never come close to making as much as either of my parents(divorced), my brothers tend to earn more(and more regularly) than me, and I am A-OK with that. I have had more trauma and ailments than any of them, but most of it was brought on by thrill-seeking and irresponsible lifestyle choices. Meh, you only live once.
No traffic, no 9-5, work from anywhere there's a signal: Priceless.
Imagination drew in bold strokes, instantly serving hopes and fears, while knowledge advanced by slow increments...
What was the sample size each year?
Approximately everyone.
Did anyone else skim (or actually read) the 2008 paper by the researchers that was linked in the article? I notice many mentions of winter months and January but nothing about February or March (or the last week of December). In fact, the tables of data at the end of the paper list by month, but omit January, or by quarter of year, but omit the first quarter. What's the point of including data for everything except the two most mentioned time periods in one report?
Something seems bogus to me.
I was born in November in Minnesota and I have an IQ of ~130.
They probably weren't measuring IQ though, they may have been measuring skills such as being able to recognise that one data point doesn't confirm or deny a trend.
Forgot to mention I got 80% scholarship.
They seem to put a kid as being disadvantaged for having a mother that completed high school in fewer years than her peers.
My webcomic
Nope, just a stats class.
Across a population, being tall confers a slight advantage in terms of income.
That doesn't mean any given tall person is going to earn more than he'd earn if he were shorter.
"Patriotism is your conviction that this country is superior to all other countries because you were born in it." -- GBS
I don't think you quite understand. Data showed that there is already a correlation between the season a baby was born in and measurable performance statistics. They have shown that some, most or all of this correlation is due to a key assumption being false;
A key assumption of much of that research is that the backgrounds of children born in the winter are the same as the backgrounds of children born at other times of the year.
Ah fuck it, I can't be bothered to explain it in full. It's too obvious.
Is this a rhetorical question?
True, the summary is poorly written - it only mentions one of three significant indicators. This IS Slashdot though. If the summaries were well written in the first place what would the editors do?
(To the sarcasm impaired: yes, I'm kidding)
One of kids born the hottest day in 50 years, one born the coldest day in 80 years, one between - don't see any difference. Now, of course, if I would need research funds I might start seeing the differences - heh! Or maybe it was the size of the car in which they were taken home from hospital (need a car analogy in Slashdot) - have to start the research, just have to get maybe government funding for it.
When your wife gets to 7.5 months, take a 6 week vacation. You get to see some different fauna be it kangaroos, llamas or wildebeest. The baby is born during summer and has an exotic location on its birth certificate.
Problem solved!
I am a December baby and I went far in school (dual Bachelor's, working on a Master's degree) and I have been very healthy. My sister, who was born during the summer, had major allergies as a kid, though she too went far in school (Bachelor's). Maybe I wasn't born far enough into winter. After all, I started school when I was 4 (vs 5) as I was turning 5 before the end of the year. Maybe I won the genetic lottery for winter babies...
David
Furthermore, if the summaries were well written, what would we have to argue about?
b) the baby's increased risk of health and education problems causes him or her to be born in the winter (clearly ridiculous)
You are assuming that the time axis is positive in all cases. Do you have a proof this is the case?
Help! I'm a slashdot refugee.
It's a pity...if only you'd been born in May, you'd have been getting a 96% average!
And that significant difference would be significant!
The CB App. What's your 20?
Birthday Blues! If my birthday was next to Christmas, I'd be depressed all the time, too.
Well, there's always someone like the second poster in this thread (modded to oblivion now) who manages to read the summary and the article and still write a post criticizing the article for... saying the same thing he just did.
Yes, but I've already shown it to you.
Dumb chicks put out in spring when they are horny.
Smart chicks put out when the crops are mature and it's clear there will be enough resources to feed another mouth.
It's amazing how much human behavior is hard wired into us.
Charming use of "put out" and "chicks". You're a regular Casanova, I'm sure.
The article clearly states that it was (almost) all U.S. births during a certain time-frame, data courtesy of the CDC.
If you'd like to post a link to the supposed correlation between Saturn and the S&P perhaps we can discuss it. Is it an actual correlation? You do know that correlation doesn't mean "has an r^2 greater than some arbitrary threshold", right?
A correlation means that there IS a link between two things. An r^2 (or r) value indicates the strength of the aparent observed connection, and is also associated with a probability that the observed connection is not simply an artifact due to chance. Perhaps your Saturn-S&P "correlation" is simply that - a statistical fluke, perhaps born of someone doing multiple comparisons and not correcting for them. Actually, that seems extremely likely. I very much doubt someone purposely compared any feature Saturn and the S&P in a single, once-off test. By the way, what do you mean by "Saturn?" It's mass? Orbital period? Colour? The Roman God's independent living index?
I don't know what the tabloids will claim (nor do I care), but the Slashdot summary is quite correct. They have found a new explanation for observed differences between winter and summer babies - the winter babies are more likely to be born of unwed, more poorly educated mothers. That explanation may not be THE explanation, but it is certainly AN explanation. I haven't done the background research to verify whether it is NEW or not, but it seems plausible. What part are you objecting to anyway? Perhaps you've confused the meaning of "explanation" with "absolute truth?" Maybe if you paid a little less attention to what the tabloids say....
Actually, you're right. The study shows that there is a small remaining association between birth month and various outcomes, but it is very much weakened when socioeconomic status of the mother is taken into account. So really the study is saying birth month doesn't cause these outcomes, at least not to the degree that was previously believed.
Actually, they have a whole section on possible explanations for why they see the trends they do, even though that is not the focus of their paper. They even use the phrase "prom baby" except that they have lots of references to actual research that has been done into the phenomenon. Of course, the actual point of their paper is to warn against drawing unwarranted conclusions from the season-outcome correlation, such as that the school intake system is unfair to winter babies. Wait... you did read the paper before you complained about it (and not just it, but condemned all of a large class of studies) right?
I think that it depends on your home life. If you were born in the winter and your home life was tough such as you were raised by a single parent, or your parent are going through a divorce, or your parents education isn't real impressive then you probably won't be awesome in school because the good example isn't there. Sometimes financial struggles of the parent(s) can also allow for less access to good schools, good school materials, and a good education. Stress from home can cause a lack of motivation in education.
3.7 and born in November, here. See what a difference just a month makes? Imagine how different things would be had we been born in summer.
I can just see it a few decades from now. Children sue their parents for giving birth to them during winter months because it disadvantages them with regards to their education.
You are correct. Birth month does not CAUSE health and education risks. But birth month does indicate an increased probability of health and educational problems. Let's see. that means that you cannot apply the generalization to specific people. But let's try. I was born in November (of poor parents). I have health problems. I am also highly educated and upper middle class,as I work as a senior engineer. My wife was born in spring, of poor parents. A few minor health problems, educational problems. My son was born in fall (of well-off parents), extremely excellent health, small educational problems (fixed). My daughter was born in spring. Excellent health, no educational problems. So does the generalization work for e? Not only do I not see that, but working for me is a meaningless statement. All It means is that the medical people and insurance companies may spend more paperwork overall on fall kids, and the feds may get less taxes overall from fall kids.
Correlation does not show cause and effect. It only shows that the two items are related (a causative link), and one may be a partial cause of the other, or there may be at least one common partial cause of both.
What is not shown at all is the causes for either greater health issues or educational issues. Far more detailed work would be required to get to that point.
Perhaps babies need the extra sunlight of the summer in their early months for better health and fewer educational problems later in life? Or just the vitamins that sunlight generates in them?
wake up and hold your nose
Actually that one wouldn't be nearly as interesting if you re-computed it with updated numbers, since the S&P 500 tanked. You don't have to cherrypick the winter birth data that way; the correlation is very robust. And now they are figuring out why.
I disagree my kind sir.
I didn't RTFA in question, but I know that my facts are right beyond a doubt.
Hahaha!! Now that one deserves to be modded up!!!
pi=sigma{n:0-infinity}[(1/16)^n][(4/(8n+1))-(2/(8n +4))-(1/ (8n+5))-(1/(8n+6))]
This correlation is entirely due to both series being upward-trending. Either the author (presumably you, from your nick) knew this or was being sloppy. To be fair, sloppy statistics are misleading, but this extends to more than just correlations.
Helpfully, the author provided the data. Applying the simplest linear detrending, I obtain a correlation of 0.0371, rather than the 0.8778 without detrending.
This same point was made more clearly by the correlation of pirates and global warming; there, it's obvious that the mistake is to look at general trending variables and infer some sort of correlation, because countless variables trend over time and you'll get a significant positive or negative correlation. With this example, it's more misleading because it might be possible that the deviations from these upward trends actually are correlated, based on the picture. But they aren't.
"The universe seems neither benign nor hostile, merely indifferent." --Carl Sagan
He paid for it with the extra years spent earning living expenses instead of a real salary to get the second 2 degrees. And for the record, my husband graduated with a 3.8 for his BSME with little to no scholarship money awarded him. Then again, maybe it's because he was born in February.
Seriously.
Who cares about some schmuck's grades? What has he published?
After all, I am strangely colored.
Loser. I was born last Sunday and had a 5.45 GPA while getting my Ph.D.Phil. in Rocket Surgery.
You do realize that if your birthday is close to Christmas, they buy you one present that's maybe 10% better than the Christmas or birthday present you would have gotten and tell you it's the gift for both, right?
Pathetic. I won't be born for another 5 millenia and I already have Ph.D.s in every major scientific, technical, and mathematical discipline. It's been nice talking to you, but I have to go back in time now and ghost write Philosophiae Naturalis Principia Mathematica for some dopey January baby. Thanks to what I'm about to do you'll certainly have heard of him - Isaac Newton. The funny part is that even after I've explained mechanics and calculus to him, he keeps insisting that he can find the Philosopher's Stone and alchemically transmogrify base metals into gold, the limey fsck-tard.
I'm no (so-called) "expert", but what strikes you as the most outstanding difference between summer and winter? Hmm? Hmm?
S-freakin-UN. SUN! And as it is already shown, that lack of sunlight causes depression, imagine what it is for a baby, to in the first months of their life think that there is no other thing than darkness and coldness!
I mean, it boggles my mind, how that can be not totally obvious to someone...
I am a fall child, and my first month of life consisted of laying mostly inside, and seeing hailstorms and rain outside. And I always had a special relationship to that weather.
If you know how the brain works, by forming very global and basic patterns at first, and then making finer and finer details in it, then this is the base imprint of your character right there.
Oh, and besides: There's your explanation for the patterns of similarity in humans, based on their time of birth (part of what is called "zodiac signs"/"astrology").
Any sufficiently advanced intelligence is indistinguishable from stupidity.
It would be interesting to see the corresponding data from developed Southern Hemisphere nations (e.g., Australia, New Zealand, Argentina). Are underachieving children in such countries more likely to have been born in June-August (the cold months) or in January-March (the same as in the US)? And how does the education level of the mothers correlate with this?
Being married with children, I can't help but agree. Having only one parent makes day to day life with children tremendously harder (as you experience temporarily if your spouse is away for some reason, such as being in hospital having the next baby). Doing something as basic as going to the shop to pick up a few items takes a lot more effort if you have to take young children with you compared to one parent going to the shop while the other stays with the children.
Of course, the strength of the relationship is more important than government certification, but people who commit to their relationships are probably more likely to legally formalise the relationship as well.
http://marriedmansexlife.com/
I'll tell you what: There's a 1:1 correlation between a comment header stating that correlation is not causation and the comment below it being absolute drivel. Yet, there's no claim that such a header causes the comment to be stupid. You know why? It's because to everyone who doesn't make those idiotic comments, the difference between correlation and causation is fucking obvious. Now fuck off and grow a brain, and stop believing that repeating "wisdoms" from the lowest class of Slashdot morons is in any way insightful.
If you read the paper (which takes about three seconds to find on Google), or the article, or even the summary (!), this story is about a pair of researchers who have found a connection between birth month and socioeconomic background of the mother that explains much of the observed connection between birth month and outcome. No (well, technically very little) musing about sunlight or vitamins needed.
haha well now I feel freakin awesome!
I was born in Europe, and I am still here. WTF is a GPA?
Sent from my ASR33 using ASCII
.... just FYI
Grade ooint average.
A is 4.0, A+ is 4.33, B- is 2.67, etc.
GPA is the average of all the numerical values of your letter/percent grades.
Or smart chicks don't want to be pregnant and hot in the summer or have kids with birthdays near Christmas/Thanksgiving or have to get to the hospital in the middle of a major winter storm. So ideally they would plan for May-June.
Thank's for that. I have been wondering exactly how signals are in fact decorrelated. I knew that any two continuous signals must be correlated almost everywhere along their runs, but I wasn't sure how to account for this. I'll be sure to add your comment to the page.
Basically my point with the Saturn/S&P correlation was to show just how spurious a correlation study can be. I think it's worth noting that along with the Hill's criteria, most studies probably don't even bother to perform such checks as linear detrending, etc. A lot of what we see in correlation studies is just as spurious and incomplete as that example. By the way, it turns out I was not the first to stumble across this result, showing that again, there is not correlation so silly that someone will not accept it as proof of causation.
Basically, my core point is that a lot of correlation studies lack rigour of the most basic kind, and are just a number thrown out to make a point. The more I learn about the subject, the more convinced of this point I become.
May the Maths Be with you!
The real issue here is the lack of rigour, not the statistical tool in particular. I find it ironic that you dislike studies with correlations because sloppy studies often (mis)use correlations.
As with any statistical tools, you need to know what they mean and how (and when) to apply them. Correlations are a very useful tool, especially early in a particular research agenda.
"The universe seems neither benign nor hostile, merely indifferent." --Carl Sagan
This is absolute nonsense. I know many people who are Capricorns (born in December-January) and who are over-achievers.
I've spent my whole life in academia and until recent liberalizations of child care policies, I noticed that inevitably women faculty had their babies in the summer. Male teachers have that preference too (my own kids are June and April). I imagine that this was true of K-12 teachers, too. A few percent of women who carefully planned for summer births would be enough to move the numbers. And notice that employed/well educated women having summer babies would cause an apparent disadvantage to winter babies (i.e., rarely born of those women). I like the prom/graduation pregnancy explanation, too. Together these might well handle the whole observed phenomena.
> then declaring that people born in winter suffer from a lifelong plight, without
> even bothering to provide genuine reasoning
You seem to be somewhat confused. There's varied observational data, predating this study, showing that children born in winter tend to do (very slightly) worse in life. The question hast been _why_ this is the case.
This study points out that:
1) Children born in winter are (very slightly) more likely to be born to teen mothers.
2) There are existing studies comparing children born to teen mothers to other children,
and those born to teen mothers tend to do slightly worse. Again, without saying
_why_, but that's the observation. Various hypotheses could be advanced to explain
it, of course.
3) One could assume (and this is an assumption) that children born to teen mothers are,
on average, the same year round and assume the same for children born to non-teen
mothers. One could then see, under this assumption, how much of the difference
observed above in item 1 is accounted for by the known observed differences of item 2.
Depending on how well the numbers one gets from the procedure in item 3 match those observed in item 1, and on how confident one feels in the assumptions made in item 3, one could make the argument that one has discovered something about the causes of item 1: namely that they are likely to be the same as the causes of item 2, whatever those are. Note that the claim is not that one has established causation of anything. However one has advanced a hypothesis: if the causative mechanisms of item 2 are discovered and can be controlled for when studying the data for item 1, one could see whether the effect of item 1 remains.
Man, that's a brilliant positive feedback loop!
Sig erased via substitution of an identical one.
It's always 1950 somewhere...
of why so many stupid, unsuccessful people like Edison, Washington, Darwin, Lincoln, Frederick Douglas, Ayn Rand, and Steve Jobs were born in the winter.
I don't think that this possibility can be dismissed as easily as you would like. It is entirely possible that congenital problems with the fetus, in combination with the stress that cold weather puts on the mother, leads to an increase in premature births in the winter months. This effect, if it exists, would push a certain number of births that would have occurred in the spring, back into the winter months and those births that moved would be precisely those at risk for health problems.
N.B. I'm not actually saying this is true, I'm just pointing out that you shouldn't be so quick to discard the "clearly ridiculous" option out of hand.
--
JimFive
Please stop using the word theory when you mean hypothesis.
Er, no, your proposal falls under (a): baby's birth month affects later outcome. That is, because of seasonal conditions during the baby's gestation the baby has problems later.
Option (b) requires that because the baby has poorer health and education later in life, it is born during the winter. That is, it requires the future (poor outcome) to influence the past (conditions of conception and birth).
Actually, I'm positing a third factor (a congenital defect) that causes both an increase in the likelihood of a winter birth and an increase in health problems later in life.
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JimFive
Please stop using the word theory when you mean hypothesis.
I wish there was an error bar I could put around the non-word "atleast" every time someone uses it...
Ah, okay, option (c) then: a third factor that influences both birth month and outcome.
Option (b) still requires time travel.