Firstborn Get the Brains

Dekortage writes "Eldest children have higher IQs than their siblings, according to a recent study by Norwegian researchers. The study focused on men, particularly 'on teasing out the biological effects of birth order from the effects of social status,' but indicates that the senior boy in a family (either by being firstborn, or if an elder brother died) has an average IQ two or three points higher than younger brothers. As noted in the New York Times coverage, 'Experts say it can be a tipping point for some people — the difference between a high B average and a low A, for instance... that could mean the difference between admission to an elite private college and a less exclusive public one.'"

the teacher

[Speare]

It wouldn't surprise me, as the act of teaching while learning tends to reinforce the learning. The oldest kid, whether consciously or not, ends up demonstrating any new knowledge and capabilities to the younger kids in the family or neighborhood.

Speaking as a middle child...

[PrescriptionWarning]

I can say that my older brother's high IQ is severely hampered by severe lack of common sense :P

Girls

[The Queen]

I'd be more interested in seeing a study that not only includes girls, but breaks down as such:

Family of only boys
Family of both with boy as eldest
Family of both with girl as eldest
Family of only girls

For my experience, I am the first born (girl) with one younger sister; I'm a graphics/web designer/computer geek and she's a scientist who works in a lab with dangerous chemicals. If there is a difference between us it's slight. I'd wager that would hold true for most girl siblings regardless of pecking order.

Subtle IQ differences

[John3]

Interesting study and the stats seem to back up their theory. However, the IQ difference is so subtle that I wonder how much difference it really makes. Does an IQ of 102 really provide that much of an advantage over someone with an IQ of 100?

Based on personal experience raising two daughters, I'm sure that part of the reason the second child lose two points of IQ is that the parents just start getting tired. :) Your first child gets all your energy, and you try out interesting things, go to interesting places. The arrival of the second child means you now divide your time and energy and so the second child will tend to lose out. When the first child leaves the house the second child is nearly full grown anyway.

I wonder if they looked at homes where the children were very far apart in age? Suppose one child was 10 when the second child was born. By that time the parents are comfortable with the progress of child #1 and might devote more time to child #2 than they would have if the children were only a year or two apart.

Re:This is obvious.

[smittyoneeach]

OK, I'm the older brother by 3.5 years, have a Master's degree, etc., whereas my brother has a high school diploma and rides in on a Harley.
I wonder, though, if there isn't a broader organizational behavior principle at work here.
Keep an eye on the phrase

the senior boy in a family (either by being firstborn, or if an elder brother died)

How often at work is there a tautology, whereby the senior headz are the only ones equipped to perform certain tasks/make decisions, simply by virtue of longevity. Once they retire, get flattened by a bus, or move on to a position at the Utility Muffin Research Kitchen, then the next person in line steps up.
Thus, I dispute the title "Firstborn Get the Brains", and offer instead that, in families as in other organizations, we do a sub-optimal job of affording the juniors the opportunity to negotiate the learning curve.
"Firstborn Get the Brains" somehow implies that the womb retains some state in between children, and knows to shortchange the later arrivals.
My younger brother and sister have also floated some really irritating cop-outs based on this birth order talk. Raises my hackles. I had been going to troll this article using Exodus 13:12

That thou shalt set apart unto the LORD all that openeth the matrix, and every firstling that cometh of a beast which thou hast; the males shall be the LORD's.

calling it subliminal Christian propaganda, but then I thought the better of it. ;)

Data points

[garoo]

Just to commit a plural of anecdotes error:

Einstein was the older sibling, as I think is Stephen Hawking, Isaac Newton, Johannes Kepler and Robert Oppenheimer - doing fine so far. On the other hand (and merely AFAIK), Blaise Pascal was the second son, Dirac was the second son, Niels Bohr was the second of three, Faraday appears to have been well into the plurals and Ernest Rutherford was the fourth-born child. Van de Graaff had three older brothers, all of whom were into football rather than physics.

All of which may go to suggest only that seventh sons don't necessarily need to sell their scientific calculator and resign themselves to brainless toil quite yet.

Re:Subtle IQ differences

[KokorHekkus]

Some facts in the article certainly could support your hypothesis that it might be down to less stimuli while young:

The average IQ of first-born men was 103.2, they found.
Second-born men averaged 101.2, but second-born men whose older sibling died in infancy scored 102.9.
And for third-borns, the average was 100.0. But if both older siblings died young, the third-born score rose to 102.6.

Another related thing I read about (some years ago) was about that truly bilingual (using both languages at home) young children had a better ability for selecitve attention than monolingual children. Selective attention means the ability to sort out the important aspects and discard unimportant ones. Which obviously helps when you're going to form abstract concepts/thoughts. Learning two languages must be a lot more intellectually stimulating for the children (doesn't need to be hard though)... and it would seem that it also helps developing their intellectual capabilities.

Re:the teacher

[Attila Dimedici]

I suspect it has more to do with amount and type of parental attention. Having watched several of my friends raise their multiple children, I have noticed that parents(especially fathers) tend to spend more time teaching things to the eldest child than to succeeding children (although the oldest of either gender gets more attention, even if they aren't the firstborn). I am the youngest of a large family and by every measure the smartest of them (including my siblings own statements). However, there is a gap between me and the next in age. My older siblings all spent a lot of time lavishing attention on me in ways that have been shown in studies to increase intelligence. I have observed that parents tend to lavish greater amounts of the same types of attention on their eldest sons.

implications of the one child policy?

[finlandia1869]

Does this mean that China's one child policy is creating a race of Han superchildren? Unless, of course, you fail to have a son the first time, then you can try again.

IQ tests and cultural bias

[140Mandak262Jamuna]

Most of these IQ tests have very heavy cultural biases. I still remember a question I flunked in one of my early IQ tests. "A bin has 25 pairs of white gloves and 25 pairs of black gloves. If you pick gloves randomly how many you should pick before you can be sure of getting a matched pair? If the bin had socks instead of gloves, would the answer be different?".

When I took the test I was a barefoot rural South Indian. The only pieces of clothing I was aware of were shorts, shirts, sarees and saree's male version the dhothi. Had never seen a glove nor did I know that there is no left and right version for the socks. The real problem is that some clueless educator bought some IQ tests designed for US or Britain and administered it to us. Or may be some lazy Indian teacher copied a western test and changed the names from Victor and Barbara to Vijay and Bhanu.

Still my point is these test dont measure anything more than knowledge and training and may be level of motivation of the parents. Let us take a all American boy from the exurbs of Chicago and give him a Kalahari IQ test.

You suddenly come face to face with a hyena. You should:

A: Throw rocks at it

B: Turn around and run

C: Curl up and play dead

D: Find a stick or a bark and hold it over your head to make you appear taller than the hyena. And wait for a Kalahari who was on a missing to throw away a coke bottle over the end of earth to appear and save you.

Re:IQ != Intelligence

[Chandon Seldon]

A quarterback who can gauge how the field looks at a given moment and decide upon a particular action is just as intelligent (in a different way) as someone who is excellent at arithmetic. Similarly, someone who has excellent social skills (i.e. read emotions) is just as intelligent as someone who has a prodigious memory. A marketing person is just as intelligent as a computer programmer in a different way, and a tennis player is just as intelligent as a musician, in a different way.

"Intelligent" does actually mean something, and some people are more intelligent than others. There are different forms of intelligence, but that doesn't mean that everyone gets one of them. There are some professions that require more intelligence than others: dumb people can play tennis, but they can't be mathematics professors. That isn't to say there aren't extremely smart tennis players, but it's not a prerequisite.

Re:Ugh IQ...

[kripkenstein]

"And, in fact, if the results were not statistically significant, they wouldn't get published very easily, and certainly not in Science."

Nonsense, much that is nonsense is published CERTAINLY in science, todays science is tomorrows superstition when dealing with crude measuring apparatus -- that being ultimately the human being which is prone to bias and overstating their interpretation of the data or doing folloup studies or later finding flaws in methodology that are not apparent, etc. Science is not immune from human frailty. One only has to look back 50-100 years to see how "scientific" many men were Freud, et, al.

Notice that I capitalized "Science". By that I meant the journal Science, not the human endeavor as a whole. Science, if you are not aware, is one of the 2 major empirical science journals (the other being Nature). Publishing there is among the highest achievements for scientists.

Indeed, scientific knowledge is prone to error. But, you cannot publish in the particular journal 'Science' if your results are not statistically significant - in the technical meaning of the term. Which is all I said, and all I meant. I did not say that the results were correct, just that they were statistically significant, which was doubted in the comment I was replying to. (You can certainly doubt if statistical significance leads to 'truth'; many scientists do.)

parental pressure

[thermal_7]

I think a big factor in this is the pressure that firstborns receive from the parents to succeed. Parents tend to pile their hopes onto the first child but are more relaxed the second time around.

Re:Which study do you believe?

[Lord Ender]

What's more interesting is the way he did it. Locke (Peter) was basically a blogger who became so popular he amassed real political power. That may seem unlikely today, but thirty years or so, when the distinction between TV and internet vanishes, it seems conceivable that someone could rise up from the media/infotainment realm into the political realm.

Vote Wiggin in '38!

Re:Flawed Study!!!

[forrestt]

I have to agree, I'm the second of two though, and while my brother always did better in school, my scores on SAT and IQ tests were 5-10% higher than his. I just didn't care about what they were teaching in school because I already learned the stuff by reading his schoolbooks.

OK, just went back and read the article (go figure)...

Kristensen, of Norway's National Institute of Occupational Health, and Bjerkedal, of the Norwegian Armed Forces Medical Services, studied the IQ test results of 241,310 Norwegian men drafted into the armed forces between 1967 and 1976. All were aged 18 or 19 at the time.

The average IQ of first-born men was 103.2, they found.

Second-born men averaged 101.2, but second-born men whose older sibling died in infancy scored 102.9.

And for third-borns, the average was 100.0. But if both older siblings died young, the third-born score rose to 102.6.

At no point do they actually tie the first born from a family with the second born from the same family. It might be that first born sons were the ones that got sent to college and were exempt (not sure if college was an exemption in Norway as it was in the US), whether they were more intelligent or not. It could be the first born sons were more financially capable of fleeing the country. It might be that the first born sons were too old to be drafted. And what about all the first born men who didn't die in infancy, but died at an older age doing something incredibly stupid? It could also be that on average, second sons are more intelligent, but "only sons" are MUCH more intelligent than average and therefore skew the average. There are all kinds of reasons that the study can easily be called flawed and account for the 2% difference.

Re:the teacher

[moderatorrater]

I remember learning in Psychology that the oldest child tends to have the highest IQ but the youngest child tends to have the next highest, indicating that it's the parents' time that's the major factor.

Re:2 or 3 points?

[porcupine8]

I can't believe you got modded Troll. Seriously, IQ tests have a margin of error of about 3 points or so, AND even a real, reliable difference of 1-3 points doesn't have any practical significance anyhow, you don't see practical differences until you get to around ten points, AND ones from the 60s were quite a bit worse than today's in terms of general usefulness. This study is meaningless.

Besides, from everything I've read, if there's a difference due to birth order it's more on motivational factors, which are hardly correlated with IQ at all.

Re:I Can explain the whole thing in 4 words.

[Daniel Dvorkin]

*snort*

I'm an only child; read into that what you will. ;)

Social environment affects intelligence

[yali]

Dunno about IQ (other than it being lower than firstborn's) but I recall a study showing that if you have an older and a younger brother you are more likely to be gay...

Such evidence does exist [wikipedia.org], but for different reasons. In the case of sexual orientation, the effect is because successive births change the hormonal environment of the womb. But for IQ it was social rank, not biological birth order. If someone had an elder brother who died young (making them biologically a secondborn but socially a firstborn), they looked like a firstborn.

This leads to an important point. All of the discussion has been about birth order, but the scientific importance of this study is broader than that. What's really exciting about this study (IMHO) is that it provides compelling evidence that family social environment affects intelligence. This flies in the face of recent arguments by Judith Rich Harris [wikipedia.org] (who has been enthusiastically received by Steven Pinker, the Freakonomics guys, and others), claiming that parents don't matter [att.net].