Firstborns have higher IQs than their siblings
July 4, 2007
This short paper from Science reports tasty findings on the correlation between birth order and intelligence. While it’s generally accepted in the scientific community that older siblings generally have higher IQs due to different environmental influences, numerous possible factors make it tricky to prove causation from correlation. One criticism is that later siblings are likely to come from larger families, which relates to lower socioeconomic status and IQ.
A study of 241,310 Norwegians shows that sibling social order rather than biological factors is what causes the variation of intelligence in siblings. This study supports the popular confluence theory, which claims that intelligence is directly influenced by the intelligence level of the other family members. Thus, older siblings benefit from extra time spent with the parents, while younger siblings are negatively affected by the other children.
In nature vs nurture, nurture takes this round.
Kristensen, P. & Bjerkedal, T. (2007). Explaining the Relation Between Birth Order and Intelligence. Science, 316(5832), 1717. [PDF]
Entry Filed under: Birth Order, Intelligence, Relationships. .
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1.
tastyresearch | July 4, 2007 at 1:47 am
If you’re interested in “pop science” birth order theories, Wikipedia has some charming descriptions of each sibling (as of 2007-07-04).
2.
Bo | July 11, 2007 at 7:47 pm
Hey - you should taclke this new study about Cumulative Advantage and why people choose to make one thing (song, software startup, celebrity) popular over others.
I found it at: (the actual NYT link requires subscription)
http://blog.pmarca.com/2007/06/paper-of-the-we.html
3.
Rebecca Aguilar | July 21, 2007 at 8:45 am
Stephen Colbert interviewed Dr. Frank Sulloway, who wrote a book (Born to Rebel) about the influence of birth order on personality.
The interview: http://www.comedycentral.com/motherload/player.jhtml?ml_video=90174&ml_collection=&ml_gateway=&ml_gateway_id=&ml_comedian=&ml_runtime=&ml_context=show&ml_origin_url=/shows/the_colbert_report/videos/celebrity_interviews/index.jhtml&ml_playlist=&lnk=&is_large=true
4.
L.A. | November 6, 2007 at 4:39 pm
Look, my brother is a good man, but there is no truth to this theory when it comes to my family. I think it depends on the effort you put in.
5.
Ashley | November 7, 2007 at 4:24 pm
I don’t really agree with the topic. My sister and I are about as smart as each other and she is older than me. She is six years older than me so by the time I came around I still got my parents attention and we are the only two in our family. My parents influenced my sister just as much as they did in me. My dad is also the third child in his family and he had the higher IQ.
6.
Josh | November 12, 2007 at 3:23 pm
This is completely preposterous! As a younger child I can say that my brother and I have almost no differences in our IQs. I refuse to believe that he is any better than me in the brain region.
7.
Sammie | November 12, 2007 at 3:36 pm
This topic for me is hard to comment on. In my family, I have an older sister and two older brothers, and a younger brother. We are all pretty smart but the first and third child are way smarter then us other 3. But we all got the same attention and love from our parents. I just believe that they picked up on things more easily or they paid more attention. I don’t think this research is true!
8.
amanda | November 14, 2007 at 3:14 pm
I think that birth order doesn’t really have an effect of your I.Q. Although I am the first born and I get better grades than my brother, he is still pretty smart but he just doesn’t apply himself.
9.
Geoffrey | February 11, 2008 at 7:06 pm
All of these comments asserting that birth-order correlations with I.Q. don’t exist are a little ridiculous.
Someone didn’t just say “hey, I bet firstborns are smarter,” there’s a HUGE amount of evidence to show that they do have higher average I.Q. scores, and the fact that a handful of people don’t think their older brothers are that smart is completely insignificant.
Nobody said that ALL firstborns EVERYWHERE are ALWAYS smarter, so you can’t unravel the whole thing with a single contradictory anecdote. There’s a mountain of evidence showing that a correlation does exist, and a pretty big one at that, so it’s going to take evidence of absolutely epically greater proportions than “I know some people who don’t fit this” to mount a counter-argument.
10.
Bryan | February 11, 2008 at 9:30 pm
Well, comment #9 is actually from my older brother and I think he’s dumb. So that settles that.