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Study Says Eldest Children Have Higher I.Q.s

Siblings

According to a large study, the oldest children in families tend to develop higher IQ's than their siblings.

These findings could settle more than fifty years of scientific debate about the relationship between IQ and birth order.

There was, on average, a three point difference in IQ between the oldest child and the next closest sibling, a slight but significant difference.

The results made it clear that the difference was a result of family dynamics, rather than biological factors; children who became the oldest child after the early death of a sibling had the same scores, on average, as biological firstborns.

The study looked at the birth order and IQ scores of more than 240,000 men aged 18 or 19, based on their military records.

After correcting for factors that can affect scores, such as parents' education level, researchers found that the oldest children scored an average of 103.2, whereas second children averaged 100.3 and thirdborn children averaged 99. The scientists then looked at the IQ scores of more than 60,000 pairs of brothers, and found the same results.

Since gender generally has little effect on IQ scores, the results likely apply to women as well as men.

The New York Times June 21, 2007


Dr. Mercola's Comment:

The 3 or 4 point advantage the oldest children get on IQ tests may not sound like much, but even such a small difference can be the tipping point for many -- allowing the older children to get into better schools, for example.

But what causes this slight jump in IQ?

There are several theories, including the idea that firstborns have their parents' undivided attention as infants. In theory this would account for their enriched vocabulary and reasoning abilities. Another possibility is that older siblings consolidate and organize their knowledge while performing their natural role as tutors to their younger brothers and sisters.

A third possibility is that siblings tend to develop different sets of qualities in order to find their "niche" within the family, without competing over the same skill. For example, whereas firstborns nab the high-IQ trophy, younger siblings tend to live more adventurous lives and their accomplishments tend to be of the less conventional kind.

That last theory brings home an important point; an IQ score is not the be-all and end-all of human existence, and people can develop many different skills in many different fields.

This study has some personal relevance for me as I am the oldest of five children, and although we've never compared IQ scores, I am the only one to have completed a doctorate degree, but more importantly, seem to have the strongest passion for learning. I have distinct memories of my mother helping me read at a very early age and encouraging me along.

This would certainly tend to support the theory postulated by the researchers and tends to make lots of sense. The fascination of having a child tends to wear off by the time number two runs around which could result in less attention and a decreased IQ.

By the way, if you want to ensure that all of your children have the highest IQ they can have, make sure that your babies are breastfed for as long as possible. Without question, this is the single most important thing that can be done. And, while relative IQ may not be everything, it is true that a higher IQ is linked to a longer life, so all of your children will benefit from this.

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Comment on This Article Community Comments (58)
 
 
Posted On Jun 22, 2007
As the oldest of six, I'm obligated to agree with this... :)

 
Alaskadude
Savvy User Savvy User, Joined On 2/2007
Alaskadude  
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zippos
Novice User Novice User Joined On 5/2007
zippos  
 
Posted On Jul 10, 2007
LOL Alaskadude


Halobeans
Savvy User Savvy User Joined On 11/2006
Halobeans  
 
Posted On Jul 12, 2007
My thoughts exactly! Im the oldest and the brightest of course :)

 
 
 
Posted On Jun 25, 2007
A lot of commentators are trying to discredit this study by looking at their own families.  Of course, even if the study is valid, it is only identifying a statistical tendency, not an iron-clad rule.  For example, it is perfectly correct to observe that men are taller than women (statistically speaking), even though you can easily find tall women and short men.

I am skeptical of the the following conclusion: "And it's now clear that this difference is not due to biological factors (such as the prenatal environment), but rather due to family  dynamics."   I recall that in Weston Price's studies of siblings, he noted a consistent tendency in groups no longer following native nutritional regimens, that the head and body structure of younger siblings showed greater evidence of nutritional deficiencies, i.e. that the mothers were becoming nutritionally depleted with successive pregnancies.  Could that not account for this IQ pattern?

 
Health Freedom
Savvy User Savvy User, Joined On 11/2006
Health Freedom  
Replied

squeegee
Novice User Novice User Joined On 8/2006
squeegee  
 
Posted On Jul 10, 2007
hi Health Freedom

I think Weston Price was correct in his theory about the younger siblings having deficiencies.  I see the same pattern in my own family and in other families - the oldest child has straight teeth, the second child maybe needs his wisdom teeth extracted, and the third child needs wisdom teeth extracted plus orthodontics.

In my evaluation of my siblings and I - and this is totally unscientific:

child #1 has perfect skull growth but had average high school grades
child #2 has less-perfect skull structure but had better high school grades
child #3 has even less-perfect skull growth (orthodontics + wisdom teeth extracted) but had the best grades (highest in the high school class)

but as per my previous post, I think IQ is certainly not a deciding factor in how a person's life plays out.  People succeed in spite of lower intelligence just as commonly as they fail in spite of higher intelligence.

 
 
 
Posted On Jul 10, 2007
Hmmmm - how about this

Our parents told us that the elder child was given a better education at a private school because he was the male in the family and would have to support a family.

I was told that since I wouldn't be supporting a family I would not need an extensive education and was given a public school education.  

It turned out he never had a family to support but I did.  So I put myself through trade school and then through college.  He works for a company and I own my own company. 

I'm a "girl" and the second in the family.  Where does this fit in all the data?????

 
zippos
Novice User Novice User, Joined On 5/2007
zippos  
Replied

evw
Apprentice User Apprentice User Joined On 6/2007
evw  
 
Posted On Jul 10, 2007
That certainly throws a monkey wrench in the works doesn't it? My mother never went to a really good college (she went to finishing school where they learned to set tables, sew, prepare menus and do their hair) and she ended up having her own business too, quite successful I might add...I am the oldest and yes I had the highest IQ but in a family where we all had IQ's in the near genius range (150+) I am the most adventursome, my middle brother the least successful and the youngest is the most conservative and financially successful...

 
 
 
Posted On Jul 11, 2007

Okay can I laugh out loud or what. I have 13 children and the IQ goes all over the place and the oldest is definitely not the highest IQ.

I had one start talking at two months and walking at five months and I 'm not talking toddling, I talking walking running climbing whatever, she is just advanced in every way. And that was after being oxygen deprived at birth. Number 13 is highly advanced also though not as coordinated as her sister.

I just think they don't do studies on larger families too often and all they have is child number one and child number two and the first one got all of mom's one on one teaching skills and the second had split attention and the third had to share with two others.

By the time you get to the sixth they have five teachers plus mom. I distinctly see an advantage for younger children in larger families.


 
Bananna
Novice User Novice User, Joined On 1/2007
Bananna  
 
 
 
Posted On Jun 25, 2007
My oldest brother has the highest IQ of the three of us - but I think its due to mercury in dental fillings and immu. shots, and bad diet, that he has a hard time focusing and is the least accomplished of the three of us (and his Dr. put him on Ritalin - sad, I told him he needs fish oils).  The middle brother has always had the best grades of the three and has always been a picky eater.  Me, well I'm biased and the youngest.  Sometimes the youngest is the most successful, I've seen that in other families.

In all it really depends on Personalities and if the person is toxic from metals, chemicals, etc., etc. and if they are getting the proper nutrition, etc., etc.

Now that I've been incorporating Dr. Mercola's supplements and recommendations into my lifestyle (i.e. fish/krill oils), I feel so much smarter these days!

Thank you Dr. Mercola!

 
helpingheart
Savvy User Savvy User, Joined On 6/2006
helpingheart  
 
 
 
 
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