Children of older fathers have lower IQs

http://www.guardian.co.uk/science/2009/mar/10/child-intelligence-older-fathers

by ksvs • 17 years ago

18 45 17 years ago

guardian.co.uk

sounddust• 17 years ago

I have always wondered - when reading articles like this - whether it would just be better to freeze one's sperm at age 20 and then save it for when you want to have a child. In fact, it might even be better to save sperm from age 14 or so to reduce even further the chance of generic mutation.

I don't know if this is easy or even possible to do (or whether using frozen sperm brings its own complications), but it's worth researching further.

whacked_new3• 17 years ago

I have wondered about this too, but I recall reading that sperm quality also varies with the current bodily state. Maybe the end of high school would be the best age. But it is a strange thought to have: you are essentially depositing unborn babies into a bank, and retrieving them when you decide you want them.

To take it further, you could freeze enough sperm for 100 conceptions, then get a vasectomy. Which probably yields an even more efficient outcome, with stranger connotations.

pavel_lishin2• 17 years ago

My stepfather has said a few times that he wishes he had taken the "further" option.

I'm not sure if I ever want kids, but something about freezing my sperm and getting a vasectomy worries me. A fire at the sperm bank, and my genetic legacy is lost forever.

(Of course I could go in for a reversal, but those don't always take, etc., etc.)

raganwald• 17 years ago

Heinlein's book "Podkayne of Mars" describes couples marrying and freezing entire babies to be thawed out later when they are older, wealthier, and presumably wiser.

delano2• 17 years ago

You don't need to wonder. You can do it and then forget about it until you're interested in it again.

ShabbyDoo• 17 years ago

I wonder if the study controlled for the selection bias inherent in the decisions of males of various ages to reproduce and in their preferences for mates. Presumably, 50 year-old men are not procreating with women their age. Do older men choose younger, but dumber women to mate with? Do dumber men end up having children later in life? Are 50 year-old men worse parents?

dangoldin2• 17 years ago

Good point.

They good control it by looking at IQ relationships of brothers potentially.

old-gregg2• 17 years ago

Pick a list of successful people you believe are intelligent. Uncheck those who don't have brothers/sisters. Then look if they're an older/younger kid in the family. I've done the exercise out of curiosity and it appears the article is correct: most famous programmers were older brothers.

latortuga• 17 years ago

While I was reading this article I felt almost the exact same thing - the whole article feels like bad science because they present the conclusion that "many scientists believe that genetic mutations that build up in the sperm of older men are to blame." Presumably, the only thing this study has shown is that lower intelligence is correlated with older fathers but the cause could be any number of factors like what you said or even, for example, that people with lower intelligences are predisposed to postpone having children.

Basically, thanks Freakonomics for bringing correlation/causation to my mind every time I read an article like this.

mhb2• 17 years ago

Correlation - xkcd

http://xkcd.com/552/

aneesh• 17 years ago

Good point. They also don't mention the standard error on their estimate. The difference of 3 points could easily be swallowed by the standard error.

ChrisMac• 17 years ago

As far as I know, a three point IQ difference doesn't have any practical effect. It may be statistically significant, but it's hardly a huge advantage to score three points higher than someone else.

hachiya• 17 years ago

With an average difference of only 3 IQ points that this study found, these children appear to be missing out on little with regards to intelligence.

I would be more inclined to believe any differences in intelligence, if there really are any, are due to the environment in which the child was raised, rather than genetic advantages and disadvantages. In today's world, I would guess that children born to 50 year old men are being born into a family where the wife is not the father's first wife, and the father is not as likely to be as dedicated a father as the younger fathers plan to be. This is a sweeping generalization, but I would wager that for those 50 year-olds who are remarried (once, twice, or more), by the fact that they did not care to keep the family intact the first time (excluding cases where the wife died), these men and their current wives would be less likely to provide a nurturing environment compared to a young father.

A sweeping generalization, but my gut feeling, based on the likely fact that many of those 50 year old fathers are remarried once, twice, or more, indicating to me that they are not as good a father as the SOME of the 20 year olds will be.

Also, statistics on society's accepted geniuses do not seem to show a correlation between fathers' ages and the intelligence of the offspring.

Here is a list I have compiled. IQ scores may be disputed, but the intelligence of these people generally are not.

Genius IQ Father's age

------ -- ------------

Einstein about 160 31

Galileo 185 44

==========================================

Bobby Fischer 187 Likely father, Paul nemenyi: 48

                         Birth certificate father, Hans-Gerhardt Fischer: 35

                         http://www.nndb.com/people/455/000024383/

==========================================

Madame de Stael 180 33

Ludwig Wittgenstein 190 42

Blaise Pascal 195 35

Gottfried Wilhelm Leibniz 205 49

John Stuart Mill 200 33

Emanuel Swedenborg 205 34

Johann Wolfgang von Goethe 210 39

As you can see, one of the highest IQ's, Leibniz's, had a father who as 49 years old.

Einstein's, considered the lowest at 160, had a father of 31, the youngest in this list.

So this is opposite the study's findings. However, I don't really see a correlation overall.

With the study's difference of only 3 IQ points on average, I am inclined to believe that age makes no difference in the intelligence of their offspring, especially in those families that provide a nurturing environment, regardless of the parents' ages.

unalone• 17 years ago

Wow! Pretty excellent research.

Question, because I'm certain somebody knows: is that story of 100 IQ - 60 = 180 - 140 in terms of relative intelligence true? Or is that just metaphorical and not actually representative of "people doing such-and-such are on different planes of existence"?

bd• 17 years ago

is that story of 100 IQ - 60 = 180 - 140 in terms of relative intelligence true?

Short answer: no.

Longer answer: http://news.ycombinator.com/item?id=407083

----

Also: as katz mentioned above, IQs of historical figures are complete nonsense. I can't believe it actually got so many upvotes here on HN.

time_management• 17 years ago

Question, because I'm certain somebody knows: is that story of 100 IQ - 60 = 180 - 140 in terms of relative intelligence true?

Not really. "180 IQ" is taken to mean two different things. Precociousness is the first; a 6-year-old with the cognitive performance of an 11-year-old has a "183 IQ". It's not terribly meaningful, though, because this says nothing about his adulthood performance, which will probably be closer to the average (usually 135-150). The second is extreme cognitive ability in adults or near-adults, on an "absolute" rather than age-graded scale, which we can't measure using an IQ test.

In general, IQ tests become less meaningful (correlating less strongly to what we consider "intelligence") after 125, and are unreliable after about 150. Many distinguished professors, even in math and the sciences, score in the 120s to 130s when tested. It's not that these people are "only" 98th percentile; the test simply isn't great at measuring the high range.

Also, for case in point about the diminishing utility and relevance of IQ: consider a relationship between a person with an IQ of 125 and one at 100. Someone at 100 is unlikely to finish college, and 125 is the average IQ of Ivy League students. Their relationship would be unlikely to last due to the extreme disparity of intelligence, as well as the different schools and jobs they would be likely to have. On the other hand, if the disparity were 150/125, they'd probably be considered to be well-matched; they'd have gone to similar schools and have similar educational/job experiences; although the disparity would be present, it wouldn't be such that the 150 would end up completely dominating the 125.

delano2• 17 years ago

That list of people is the most interesting part of this thread.

katz5• 17 years ago

> I would be more inclined to believe any differences in intelligence, if there really are any, are due to the environment in which the child was raised, rather than genetic advantages and disadvantages.

Intelligence measured by the general intelligence factor is highly heritable. The general intelligence factor is a factor analysis of intelligence and is a measure of “innate” intelligence and attempts at “boosting” this fails. The test that measures this the best is Raven's progressive matrices which is culture and language negative. The general intelligence factor is highly correlated with IQ and highly correlated with future success. The performance of a person in these tests has to do with the physical make-up of the brain (there are a lot of online articles by (dr/prof) Haider that is fairly readable that sheds light on this subject.)

> Here is a list I have compiled. IQ scores may be disputed, but the intelligence of these people generally are not.

A note about your cited IQs – it is probably not correct. The popular press like to “guesstimate” the IQ of historic persons – but this is of little value. Rigorous intelligence tests (such as IQ tests) is a 20th century phenomenon. Leibniz lived in the 17th century – well before these tests. So to try and determine any IQ or measure of intelligence from him is a waste of time.

Also – you collected only a point sample - I bet someone could get the same example with selecting a different group of famous persons. You also only selected the top 1% and not the general populations – so to draw assumptions of this sample to the general population would be wrong.

I do agree with you that the study is somewhat worthless. Here are several conflating factors:

People involved in menial labour (i.e. without tertiary qualifications) generally get children at a younger age. A lot of older financially secure men would generally marry younger less intelligent women (trade-up/Russian bride phenomenon). The age of child bearing of different social classes differs significantly.

Also - a three point IQ difference with all these conflating factors would probably fall under the heading "not statistically significant".

tokenadult7• 17 years ago

The test that measures this the best is Raven's progressive matrices which is culture and language negative.

I've attended a lecture by John Raven, the publisher of that test, and he doesn't make that claim.

The long, careful examination of what the Raven tests show, in conjunction with other evidence, can be found in James R. Flynn's excellent book What Is Intelligence?, which is about to come out in a new, expanded edition.

http://www.amazon.com/What-Intelligence-Expanded-PB-Beyond/d...

Also very good for reconsidering the importance of IQ tests is Keith Stanovich's What Intelligence Tests Miss.

http://yalepress.yale.edu/yupbooks/book.asp?isbn=97803001238...

http://www.amazon.com/What-Intelligence-Tests-Miss-Psycholog...

trapper• 17 years ago

Why is it people don't understand that all groups have different means given large enough N. Statistical significance has nothing to do with the magnitude of difference. Effect size is what you are looking for which looks at the magnitude of the difference in means taking into account the groups variance.

Also, 3 may well be statistically significant, and perhaps have a large effect size. This does not mean it is clinically significant.

tokenadult7• 17 years ago

IQ scores may be disputed, but the intelligence of these people generally are not.

The IQ scores claimed for these historical figures would have to be very strenuously disputed, because most of those persons never took an IQ test. The book Terman's Kids

http://www.amazon.com/Termans-Kids-Groundbreaking-Study-Gift...

by science writer Joel Shurkin, the first independent researcher to have access to the Terman longitudinal study files, explains the fanciful way in which those figures were arrived at. They were not validated by the member of Terman's team who made up those historical guesses at the IQ scores of people dead long before IQ tests were ever used.

Have any of you ever wondered how lists like this are compiled? It's laughable when you look at what was actually done to make these unvalidated guesses.

cosmo7• 17 years ago

Can we draft a law preventing journalists from trying to interpret statistics?

tokenadult7• 17 years ago

First let's teach college teachers of statistics (who usually aren't statisticians) how to teach statistics. One of my favorite articles on that subject

http://statland.org/MAAFIXED.PDF

is so thoughtful that I reread it from time to time just to savor the language. Another good article about how to teach statistics

http://repositories.cdlib.org/cgi/viewcontent.cgi?article=10...

is helpful in guiding people who have studied statistics before to rethink what they think they have learned. It is by a very eminent statistician.

tokenadult7• 17 years ago

It looks like several journalists need to read the new book Intelligence and How to Get It by Richard E. Nisbett,

http://www.wwnorton.com/catalog/winter09/006505.htm

which I am reading just now. Nisbett reviews the best recent literature on IQ testing and what it means, and punches holes in the fallacious reasoning used by many advocates of a strong hereditarian view of influence on IQ.

A really good book for background reading on IQ testing and how it works is IQ and Human Intelligence by N. J. Mackintosh,

http://www.amazon.com/IQ-Human-Intelligence-N-Mackintosh/dp/...

which includes very clear explanations of how IQ tests have developed historically, how they are currently constructed and validated, and what we still don't know about human rationality despite a century of IQ testing.

mhb2• 17 years ago

The same study found that children's IQ was marginally higher if they were born to older mothers, a finding scientists have put down to those women spending more time caring for and nurturing their infants.

Maybe younger fathers are more nurturing.

vermontdevil• 17 years ago

This is purely anecdotal but my grandfather was 60 when my dad was born. By all accounts my dad was a highly intelligent man who achieved well in the Navy despite not finishing high school (needed money).

huherto• 17 years ago

On the anecdotal side. A friend was born when her father was 75. Some people say she is a genius (clearly an exaggeration) but she s smart any way.

known• 17 years ago

You are a product of your environment. --Clement Stone

Children of older fathers have lower IQs

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