Study: First Born Have Higher IQs

Birth order may modestly affect IQ scores, favoring firstborn children, according to a new study.

The study, published in the journal Science, shows about a two-point gap in average IQ scores among firstborn men and men with living older siblings.

The study included nearly 244,000 teenage men in Norway. The men, who were 18 and 19 years old, took an intelligence test as part of Norway's compulsory military board examination.

The researchers included Petter Kristensen, M.D., Ph.D., M.Sc., of Norway's National Institute of Occupational Health. They noted whether the young men had any older siblings, including brothers or sisters who were stillborn or died in childhood.

Firstborn men had average IQ scores that were slightly higher than second-born men with living siblings. The same was true of second-born men and third-born men with living siblings.

But strict birth order wasn't the only important factor.

Men who had an elder sibling who had died had roughly the same IQ scores as firstborn children, the study shows.

Biological birth order (which includes all children in a family, including those who have died) and social birth order (which includes all living children in a family) may be equally important with respect to children's IQ scores, note Kristensen and colleagues.

The results held when the researchers considered other factors, including the parents' education, mother's age when she gave birth, and babies' birth weight.

However, an editorial published with the study points out that before age 12, younger children tend to outscore their older brothers and sisters on intelligence tests.

"This is because the younger sibling, being linguistically and cognitively less mature, degrades the firstborn's intellectual environment, whereas the older sibling enriches the second-born's environment," writes editorialist Frank Sulloway, Ph.D., of the Institute of Personality and Social Research at the University of California, Berkeley.

That pattern seems to reverse over time, perhaps because older children get an intelligence boost from being their younger siblings' informal tutors in the ways of the world, Sulloway notes.

Calling the Norwegian study "elegantly designed," Sulloway says the greatest challenge is to find other large data sets to investigate other possible explanations for the findings.
By Miranda Hitti
Reviewed by Louise Chang, M.D.
? 2007, WebMD Inc. All rights reserved

[hermit22]

Thes kant be tru; i wuz da 14 bebe ma mama hed em i gut hu grat edumakation. im lernen to flipa da burgas now. Ma mama be proud uf me en stuff.

Posted by rushlimpdrug at 09:28 AM : Jun 22, 2007

rushlimpdrug! i lub yu.

you gave me the best laugh of the day! tanks alot. you must be in the middle! LOL

who wrote the rules? first born.
who made up the test? first born?

did the second born manage to get in line within two points even if he has to put up with the first born looking his nose down at him for a lifetime? as for the babies who think THEY are the smartest....every one knows they think the world revolves around them no matter how dumb and discusting they might be.

[hmmagain]

if i climbed a rope in gym class but am afraid but made to, will they settle out of court for a dollar?

[cat1dog5075]

I don%u2019t have any brothers or sisters so I could care less either way but to me this seems stupid -First of all two points is not that much and in any experiment there is usually room for mistakes - Then to put in big bold print at the top of the page %u201CFirst Born Have Higher IQs%u201D makes it look like ABSOLUTE truth - When in fact it is not - In was just men in Norway who were 18 and 19 years old and for or all we know even culture could play a part - You could also argue that the younger siblings are smarter because not only did they have their parents to learn from but they also had the rest of the family to process information from -

Also the %u201Ctest%u201D was part of Norway's compulsory military board examination - For all we know some people wanted to do bad on it to stay out of the military or for some sort of reason like that -

Did you notice it said %u201CHowever, an editorial published with the study points out that before age 12, younger children tend to outscore their older brothers and sisters on intelligence tests%u201D-
At the age of 12 the younger is smarted - Then at 18 the older is smarter - Duhhh
So why even put %u201C %u201CFirst Born Have Higher IQs%u201D at the top of the page when at different ages it is not true - How about when you are 30 or 45 -
This experiment seems to hold no scientific value but I am sure someone made money off it

[hober_mallow]

Does this hold true for cavemen (and cavewomen) as well?

If something's so easy a caveman could do it, is this based on the oldest caveman in a family, or the younger siblings?

[tuckerndfw]

Two points is hardly worthy of the money spent on this study.

I am the youngest of seven children and it's quite obvious to me I am MUCH more intelligent than any of my siblings.

As far as that goes, I'm much more intelligent than anyone in my family.

Would someone loan me a dollar? I'm too smart to work at some menial job. And, I'm busy studying the effects of sleep on happiness, which precludes gainful employment. I hope to publish my findings in about 20 more years.

[samthetvcat]

Actually, it's kind of a skeevy job he's got - I asked him whether anybody ever implements the suggestions he and his team provide and he said no. The corporations just use firms such as his as the excuse for downsizing big chunks of their employee base - like oh so and so told them to do it. As the baby of the family I wouldn't find this kind of job very rewarding . . .

[samthetvcat]

My brother's a Management Consultant now giving advice to corporate America - probably telling them how they too can 'pass gass' and call people 'dork-wads' metaphorically speaking (lol!)

jk - my brother's cool . . . my family were one of the few people who steered me more towards the debate team and Time magazine when I started to discover make-up and boys . . .

[shoujoboy-2009]

Seriously!? All my brother did was beat the *** out of me on a daily basis and then threaten me if I told on him. Then he went off and failed to graduate high school and is now working a dead end job as a debt collector, who I'm sure has seen his own name on the "to call" list. Nothing like bucking the trend.

[samthetvcat]

"This is because the younger sibling, being linguistically and cognitively less mature, degrades the firstborn's intellectual environment, whereas the older sibling enriches the second-born's environment," writes editorialist Frank Sulloway, Ph.D., of the Institute of Personality and Social Research at the University of California, Berkeley."

omg - we degrade the intellectual environment? Obviously this first-born isn't remembering all the times they passed gas in their siblings' face and called them names like 'dork-wad'.

I think if there is generally a 2 point difference in IQ it's maybe being in the environment of the parents relying on the oldest to be more responsible and a role-model . . . if expectations are higher then maybe older siblings generally work harding and therefore generally give their brains a better work-out.

Like haven't they also shown that exposing your kids to music makes them smarter, etc?

[murry2k5]

ABSOLUTLEY! Makes perfect sense the first copy is always the best......... and everyone knows there is middle child syndrome and baby syndrome..... I belive this for one.