

Research Finds Firstborns Gain the Higher I.Q. - baha_man
http://www.nytimes.com/2007/06/22/science/22sibling.html?ex=1340164800&en=727b74a8f5602af8&ei=5090&partner=rssuserland&emc=rss

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greendestiny
I've seen this study before and while its certainly measuring something, what
its measuring doesn't seem to fit the definition of IQ. Considering it says
that younger children score higher when under 12 then vice versa, IQ isn't
really suppose to be changeable especially at that kind of age.

The social expectations on the first born may cause them to concentrate harder
perhaps, who knows. And while its a large sample its from a particular source
that may include systematic biases. If smarter younger kids managed to get out
of military service in disproportionate numbers that would skew the results.

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yagibear
I'm intrigued that the stated IQs seem above-average (100):

"In the study, Norwegian epidemiologists analyzed ... military records. ...
the researchers found that eldest children scored an average of 103.2, about 3
percent higher than second children (100.3) and 4 percent higher than
thirdborns (99.0)."

103.2 more than compensates for 99.0.

Since Norway has mandatory military service
<http://en.wikipedia.org/wiki/Military_service#Norway> , this does not refute
jokes about "military intelligence".

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paulgb
Especially considering that there will always be more first-borns than second-
and third-borns. I'm not sure if the bell-curving is done internationally, but
I would bet it is - otherwise it would be useless as a measure of intelligence
between different nations. So the difference would be explained if Norway has
a slightly higher IQ than average.

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karzeem
So the study concludes that eldest children turn out smart, as do those who
are the youngest by a large margin. One more example of middle children never
catching a break.

(Full disclosure: I'm the eldest in my family).

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cstejerean
I've suspected this might be true for a long time. simply from observing
friends, etc. I hope more research is done in this area.

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hga
I wonder about this.

There's _something_ to it, e.g. MIT students are overwhelmingly eldest or only
children, but I can't see how individual observations like you and I can make
would be able to distinguish a 3 to 4 point IQ difference.

Finer measurements and larger sample spaces are required, I'm sure.

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cstejerean
I certainly can't tell apart people with a 3 point IQ difference but as the
article mentions it is possible that this kind of differences would accumulate
over time. For example the difference between an A and a B is pretty small on
a case by case basis, but it's a big difference between a straight A student
and B average student.

