Birth Order & IQ Differences

[Totenkindly]

Families' Eldest Boys Do Better on Tests

Boys at the top of the pecking order -- either by birth or because their older siblings died -- score higher on IQ tests than their younger brothers. The question of whether firstborn and only children are really smarter than those who come along later has been hotly debated for more than a century...

...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...

I guess my question here is, is this actually a significant difference? 2-3 points of IQ maximum (if that)? I suppose there is a bell curve, so a few people won't seem to improve at all while another group will show more significant improvement, but still...

It reminds me faintly of making a large deal about how someone's cancer rate might be 50% higher than another group's... but if the chance of contracting cancer is only 0.0020% to start with, is 0.0030% really much different, practically speaking, and worth all the hype?

 

[The Ü™]

I think there are more important (and interesting) issues that we should divert our attention to -- like the future of weapon technology and alternative forms of capital punishment.

And I'm personally more interested in the future of Industrial Light and Magic.

 

[ptgatsby]

Families' Eldest Boys Do Better on Tests

I guess my question here is, is this actually a significant difference? 2-3 points of IQ maximum (if that)? I suppose there is a bell curve, so a few people won't seem to improve at all while another group will show more significant improvement, but still...

It reminds me faintly of making a large deal about how someone's cancer rate might be 50% higher than another group's... but if the chance of contracting cancer is only 0.0020% to start with, is 0.0030% really much different, practically speaking, and worth all the hype?

IQ is considered accurate to 15 points. Even using large numbers and averages/medians/whatever, that borders on trivial.

This is reinforced by the numbers, since they show that it is environmental and can be controlled for. More resources are likely allocated to the earlier kids, meaning this IQ is more crystalized than fluid (ie: more learned than anything else, and could be overcome by simply studying/learning/whatever more).

 

[The Ü™]

An IQ is like religion, it doesn't really mean anything but you can use it to get others to listen to you.

I also went to an anti-racism page that claimed that racists have lower IQs than non-racists. Since when does your view towards people have anything to do with intellectual capabilities?

I smell a bias.

 

[Totenkindly]

An IQ is like religion, it doesn't really mean anything but you can use it to get others to listen to you.

I also went to an anti-racism page that claimed that racists have lower IQs than non-racists. Since when does your view towards people have anything to do with intellectual capabilities?

That's nice, but we're discussing whether there's any significance in eldest children have 2-3 points more of IQ, not a moralistic stance of what value IQ actually might have, if any, in society.

More resources are likely allocated to the earlier kids, meaning this IQ is more crystalized than fluid (ie: more learned than anything else, and could be overcome by simply studying/learning/whatever more).

I was also pondering whether being the eldest simply means that, more often than not, you're forced to take more responsibility for issues and have to develop solutions, whereas the younger ones are slightly more inclined to look to the elder for direction and solutions.

(I.e., the elder is trained by birth position to develop more innovative skills, creative solutions, and problem-solving skills)

The increase seen here would seem to be equitable to that sort of training, just a slight increase in thinking skills.

PS. Obviously I know there's no DATA here... this is pure conjecture on my part. (Suck it up, princess.)

 

[ptgatsby]

An IQ is like religion, it doesn't really mean anything but you can use it to get others to listen to you.

IQ means a lot, actually. It is highly correlated with a great many factors.

I also went to an anti-racism page that claimed that racists have lower IQs than non-racists. Since when does your view towards people have anything to do with intellectual capabilities?

They are somewhat correct. Casually, racists and ethnocentric behaviour in general indicates a lack of openness, which correlates lightly to IQ. More than that, heavily biased racist individuals are generally very far on the closed side of the curve, which has a stronger correlation to IQ.

Having said that, the correlation is still pretty weak... but it does exist.

(FWIW, both are a subset of the individuals willingness to examine their own and others ideas, one of the fundamental correlations to IQ. That is how they are related, in theory.)

 

[nightning]

IQ means something... but an average difference of 2 points in IQ between first/second born is negliable considering the normalized standard deviation of IQ tests are fixed at 11. The tiny different there, to me, means nothing more than a sampling error. Unless there's more info given on the data... ie SE/variance, the average IQ scores can't be compared.

 

[ptgatsby]

I was also pondering whether being the eldest simply means that, more often than not, you're forced to take more responsibility for issues and have to develop solutions, whereas the younger ones are slightly more inclined to look to the elder for direction and solutions.

I can't really say without knowing what test they used. If this is a g loaded test with both gF and gC, like KAIT, then I'd believe the major contributor would be gC. This would indicate a heavy environmental pressure to learn and wouldn't indicate any ability to actually be inherently 'smarter'. I can't say for sure, however, since the article specifies that the brothers died in infancy - I'd need to see at what point in development the spread was eliminated, and the breakdown of IQ scores between the two factors.

(I.e., the elder is trained by birth position to develop more innovative skills, creative solutions, and problem-solving skills)

I keep hearing this but I have my doubts. That's why I need to know what type of intelligence was higher. Twin studies have shown that genetics is far more dominant than environment and in those cases, environment seems dependent on a lot of nurturing factors, not social order. So the gap could exist... but even if it was as high as this article stated, would be extremely minute.

The only thing I do agree with is that first born trend towards being more responsible and higher job positions. I believe that can be explained through social order. IQ, not so much.

PS. Obviously I know there's no DATA here... this is pure conjecture on my part. (Suck it up, princess.)

There is data, the question is what to look for next. That's what NT thinking should revolve around. My complaint is when people, especially NTs, only look far enough to validate their opinion. They build this framework of what it 'must be', then defend it. In my eyes, that's foolish. The goal in discussing is to be challenged. If someone brings up an alternate theory that also fits the data you originally built the theory on, you identify the data that would prove yours or the other's theory and find it. This is impossible when there is no initial data.

I believe that to be the healthy application of NT personalities. The unhealthy equivalent is to merely construct theories and never validate them. Without the outside pressure, the NT drifts into the same arena that hardcore SJs do, or paranoid flight NFs do... It's not different - draw upon the opposite side to validate your own methodology. I'm certainly not strong enough to be an SJ, to work within the fact checking/data driven environment, but it is healthy to draw upon those same traits to strengthen your preference.

[/rambling]


I thought IQ tests used a SD of 15, not 11. WAIS and KAIT both do, anyway.

(Sampling)
The sample of 243k+ was more than enough, though I'd want to see what amount of those had elder siblings die in infancy. It should be a rather small group, probably less than 6%, or about 15000 ... and probably only ~900 with two dead siblings in infancy. Just guessing based on child mortality rates.

Still sufficient, but yah, I'd need to see the spread since there is a clear bias towards military applicants, excluding those that prefer civil service. It is likely that the older ones are more responsible, which could correlate to gC.

 

[The Ü™]

I was also pondering whether being the eldest simply means that, more often than not, you're forced to take more responsibility for issues and have to develop solutions, whereas the younger ones are slightly more inclined to look to the elder for direction and solutions.

(I.e., the elder is trained by birth position to develop more innovative skills, creative solutions, and problem-solving skills)

This is logical, but isn't it funny that the media often portrays the youngest as the most intelligent?

I would say, though, that the firstborn is more likely to be the fatherly/motherly sibling.

 

[nightning]

My bad... SD is 15... I don't know where 11 popped into my head from.

I tried looking for that Science paper that article was referring to... couldn't find any "new research" from the search... a 1960s paper on IQ and birth order popped up though. But it's not overly helpful.

The thing with IQ is.... just what exactly does "applitude" mean? Does it not intuitively mean the innate ability to learn things quickly? If so, it seems wrong that your up-bringing, which should technically be the only thing birth order can influence (let's leave the utero business out of it), can affect something that's innate.

Of course you can turn everything around and say IQ isn't strictly innate. Afterall the verbal portions depends on education... even number logics to a certain degree do as well. But it goes against the whole idea that IQ... the G quotient should be "universal"... that culture and background shouldn't matter. I guess I'm just being too idealistic here. =/

 

[ptgatsby]

Of course you can turn everything around and say IQ isn't strictly innate. Afterall the verbal portions depends on education... even number logics to a certain degree do as well. But it goes against the whole idea that IQ... the G quotient should be "universal"... that culture and background shouldn't matter. I guess I'm just being too idealistic here. =/

It largely depends on the test - the WAIS, which I'm guessing is something similar to what they used, isn't so great for that kind of a bias. A heavier g factor (gF and gC) will tend to improve on that, such as the KAIT.

Also, IQ is heavily geared around problem solving (ie: answering questions)... so there will always be a skew towards practise. I believe that is fair - the question it answers is what you can answer at the present time and it has been shown that it remains relatively consistent through the person's life. That is, if you don't excersize your mind now or in the past, you aren't likely to improve going into the future either!

In any case, it is important to know what type of test was used, for sure.

 

[Wolf]

Crackpot theory (like the above, but at least I'll admit to it):

More likely, it's due to physiological factors - first-born children get more resources while they are developing, whether inside or outside their mother, then the following children get less, therefore first-born children tend to be stronger, taller, more-robust, and smarter. If the first dies, the second will get nearly as much as the first due to the way things work.

There's also the fact that first-born children get more attention, therefore they have more opportunity to learn than their younger siblings, which will split the attention with the older ones...

 

[ptgatsby]

Another theory that popped into mind.

It could be that parental age is a factor, either;

1) Generation gap
2) Absolute age 12

Of all the theories I'm likely to give weight to, with such a large sampling size, parental age could have an impact. No, it doesn't explain why IQ jumps up if the first born dies, but does explain why there is still a downward skew for each child that comes after.

 

[booyalab]

This is logical, but isn't it funny that the media often portrays the youngest as the most intelligent?

That's because the media is the youngest sibling in the family of society. Manipulative, irresponsible, at times entertaining, and gets away with murder.

 

[Geoff]

Crackpot theory (like the above, but at least I'll admit to it):

More likely, it's due to physiological factors - first-born children get more resources while they are developing, whether inside or outside their mother, then the following children get less, therefore first-born children tend to be stronger, taller, more-robust, and smarter. If the first dies, the second will get nearly as much as the first due to the way things work.

There's also the fact that first-born children get more attention, therefore they have more opportunity to learn than their younger siblings, which will split the attention with the older ones...

It doesnt appear to be physiological. In the stats, those second bornes who's first borne elder sibling died young, then end up taking their place, IQ wise. So it appears to be upbringing and not resources.

Perhaps it is time available devoted when very young to things like learning to read?

-Geoff

 

[Sahara]

Interesting, does this only reflect a study of boys?

I am the second to eldest (the eldest is female) and I have the highest IQ by a good 30-40 over all of my siblings that I know have been tested?

 

[Sona]

Families' Eldest Boys Do Better on Tests



I guess my question here is, is this actually a significant difference? 2-3 points of IQ maximum (if that)? I suppose there is a bell curve, so a few people won't seem to improve at all while another group will show more significant improvement, but still...

It reminds me faintly of making a large deal about how someone's cancer rate might be 50% higher than another group's... but if the chance of contracting cancer is only 0.0020% to start with, is 0.0030% really much different, practically speaking, and worth all the hype?

I don't know about all that though. My older brother is dumb as hell though. But earns almost as same as my dad and my dad earns alot. Me and my older sister are the smartest ones in the family. However, everyone in the family says am the smartest one and yet the most useless one.

 

[Wolf]

It doesnt appear to be physiological. In the stats, those second bornes who's first borne elder sibling died young, then end up taking their place, IQ wise. So it appears to be upbringing and not resources.

Perhaps it is time available devoted when very young to things like learning to read?

Notice that the first died in infancy. This causes physiological changes in the mother so she will devote more resources to the second child. For instance, she will not be breast feeding her first while carrying her second, which means more resources for the second child.

It actually makes a lot of sense. First born children are larger and healthier, and if you have no older siblings that survived infancy, you'll be larger and healthier.

 

[Alesia]

I'm studying to be a Speech Language Pathologist, and it is a known fact, that the more time a parent spends talking to a child, and the child learning to speak, and then to read has a great deal to do with the development of language and IQ.

Perhaps, if the youngest of the family isn't given the same amount of quality time from the parent, being read to, excetera, then IQ could suffer. So could language development.

Typically, a parent has less and less time to spend on a child the more that they have. So it has been common to see the youngest of a group of, say, 12 children come in for language disorders. But they improve almost instantly (if nothing else is wrong) when given the time to learn. Otherwise, if they did not come in to see a Speech Language Pathologist or did not otherwise obtain some instruction and attention to their development, their development would suffer, and hence their IQ, even over their lifetime.

 

[Athenian200]

It doesn't sound like the sample size was large enough to completely validate that conclusion. It might be true, but it might not be. There's no way to know for certain one way or the other. Personally, I worry that if they could know, younger siblings might be discriminated against for being inferior. And parents might be pressured to have only one child. (Of course, some people advocate population control, but that's another topic.)