Birth Order & IQ Differences

[FDG]

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.

Agreed, we should have all the info on how the data has been collected and crunched to see if it's significant. In fact, the article hasn't stated if the statiticians have claimed it to be significant or otherwise.

I think it's been said before in a post that there's a correlation between language ability and time a parent spends with the child. This means that in order to more accurately test if the impact is sweked towards this factor, they should control for age difference between siblings.

 

[Anentropic IxTx]

I am the eldest sibling of three and have always done well on tests. I'm quite sure I have a relatively high IQ.

interested in the future of Industrial Light and Magic

True.

 

[A Schnitzel]

I don't really want to give away our IQ scores on a public forum, but there is much larger than 3 point difference between my older sisters professionally tested IQ score and mine.

While it's probably true that there is a measurable difference between siblings over the entire population, it would get washed out by a large variation between families.

 

[Mondo]

I am part of a family where everyone has high IQs.
Not surprising, given that both my parents are really smart.

However, I would say the most intellectually accomplished in my immediate family is my older brother (who is the eldest child) by far (did a lot of science/math research in high school, majored in math at Harvard, is finishing up his Philosophy PHD, was pretty much the model student...).....and I believe he has the highest IQ of us.

 

[Prototype]

... Honestly, what is the significance of this "Higher IQ/Older sibling" theory?

 

[ptgatsby]

... Honestly, what is the significance of this "Higher IQ/Older sibling" theory?

It would help narrow down causation factors in intelligence.

(And make some first borns feel more special than they really are, of course.)

 

[entropie]

Wasnt there even a time where they killed their firstborns ? That would explain a lot

 

[Darjur]

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.

The youngest are the most rebellious. I can't remember it exactly but I think there was a study done on this.

Basing on information that is currently somewhere in between my ass cheeks I could hypothesize that what's more likely is that the younger aren't more intelligent, but are more prone to try to prove what ever intelligence they have.

 

[Totenkindly]

Wasnt there even a time where they killed their firstborns ? That would explain a lot

In China, they did, if the firstborn was a girl and then a boy came along.
(But that's probably not what you were thinking.)
Sigh.

 

[sade]

The youngest are the most rebellious. I can't remember it exactly but I think there was a study done on this.

Based on the empiric results from the people I know and their families, I'd confirm that. Someone needs to make the way for the others..

 

[NewEra]

This seems somewhat accurate. I've found that younger siblings are usually (but not always) dumber than their older ones.

 

[mortabunt]

The IQ thing might be accurate. My ISTJ older twin is a straight A student. I'm a B+ student.

 

[Totenkindly]

Steven Pinker (in "The Blank Slate") says actually that birth-order social bonuses/negatives don't carry through outside the family into general society. IOW, if you're the eldest in your family, then you do have a particular role there... but it doesn't clarify how you'll act and compose yourself in the wider populace.

 

[Stanton Moore]

This seems somewhat accurate. I've found that younger siblings are usually (but not always) dumber than their older ones.

Hmm...my family is the reverse of this. The youngest is the most intelligent.

 

[Fluffywolf]

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?

We did a test 5/6 years back, some national IQ test on tv.

My brother, 3 years older (ENTP, 23) scored 126.

I (INTP, 20) scored 138

My sister, (ESFJ, 17) scored 110, we were actually amazed since my sister had the lowest education of us all due to her dyslexy.

 

[Kingfisher]

Steven Pinker (in "The Blank Slate") says actually that birth-order social bonuses/negatives don't carry through outside the family into general society. IOW, if you're the eldest in your family, then you do have a particular role there... but it doesn't clarify how you'll act and compose yourself in the wider populace.

i think that's probably true. but i do think the role you have in your family influences how you act outside your family. your family can be somewhat of a model for interacting with people, since they are the first strong relationships you develop. so i guess what i am saying is, if the oldest child is for instance the 'smart kid' in the family, i think they develop patterns of behavior within the family that they are likely to carry over to the world outside the family. and maybe they tend to extrovert or focus their intelligence outside of the family too.

for what it's worth, i am the younger of 2 brothers, and my brother was much smarter than me.

 

[NewEra]

There is a basic explanation I got for the higher IQ of older siblings. There is nothing biological here, it's more psychological than anything else. The older siblings have (in general) more responsibility than the younger ones and have a tendency to act more mature. Their IQ increases. Why is it purely psychological? Because the IQ of the younger siblings rose almost 3 points on average (quite a lot) when the older siblings died.

The IQ thing might be accurate. My ISTJ older twin is a straight A student. I'm a B+ student.

But that doesn't say anything about IQ. He could be more hard-working than you.

 

[tibby]

This seems somewhat accurate. I've found that younger siblings are usually (but not always) dumber than their older ones.

How can you tell a person is dumber? And what does that "dumber" mean, how does it display itself?

Younger siblings take on different roles in their families; as do older siblings. Older siblings probably prolly will have to learn how to adjust to situations and repress their frustration more to an extent. It's complex and multifaceted, but it determines a lot - what we're expected of, how we're perceived as, what kind of behaviour is encouraged & symphatised & gains relatively more positive feedback etc. Filling holes. Younger siblings may have it easier on the parental expectation card and depending on the individual that lowers the motivation for approval-seeking and depending on the individual can manifest in many ways... And that with very many other variables.

Unless this thread was about some biological factor that determines the younger ones being born "dumber" as default?

But one very important factor to consider I believe in all of this IQ babble is self-efficacy. People with high IQ would theoretically have an advantage when it comes to it, but it's far from being the lone determinant. "Can I do this" - people with high IQ can struggle equally because of emotional roadblocks (upbringing).

Of course parenting can have an impact on harnesting and cultivating their offspring's abilities. If the "stakes" are put on the older ones shoulders and far less / none on the younger ones (stereotypical) - maybe the price of falling wouldn't be as devastating for the younger one as it'd be for the older - and would make the older try harder (for whatever here is the valuable factor, be it success in academia, work etc). But that's really black & white actually... May it be the appereance that's more important than the innate will for growth in x ? That would explain some of it, if there's something to be explained.

 

[NewEra]

This seems somewhat accurate. I've found that younger siblings are usually (but not always) dumber than their older ones.

How can you tell a person is dumber? And what does that "dumber" mean, how does it display itself?

I made that statement way back in January, don't really know why I said that. I think I took the example of one family I know. Read my response today (right above yours) to see a more accurate opinion of mine.

 

[AOA]

(IQ scores in birth order)

Me: 103 to 110
Sister (ENTP): 144
Brother (INTJ): 167
Littlest sister (ENFP): 89

... So, I wouldn't know for sure about any particular correlation, here.