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This wikipedia article on fertility and intelligence (citation missing from wiki article needed for proving this claim) indicates that intelligent people are less fertile. Is this correlated to the number of children as well?

Thus, could one infer that intelligent people, whom are quantitatively defined by IQ, generally have fewer offspring?

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    It's well known that people with higher IQ have on average fewer children. But it's usually assumed that this is because they're too busy employing that IQ to raise children. E.g. a manager working 100 hour weeks isn't going to spend as much time between the sheets with her husband as does a file clerk working part time :) – jwenting Aug 22 '11 at 6:10
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    @jwenting Wasn't Einstein a file clerk? – James Aug 22 '11 at 20:32
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    @jwenting Richard Feynman was a notorious womaniser, bongo-player and part-time theoretical physicist ;) – John Lyon Sep 21 '11 at 6:47
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    @jwenting: generally men who try to "attract women into their bedroom" are not the ones who contribute most to number of children... There is a much stronger correlation between poverty and number of children then IQ and number of children. Of course there also is a correlation between IQ and poverty so... – nico Sep 21 '11 at 6:59
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    @jwenting: I didn't know they had US Patent Office in Switzerland ;-) – vartec Oct 21 '11 at 9:07
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You would not need to "infer" that people with high IQ generally have less offspring; this concept has long been known to be true, statistically. Just note that "fertility" as defined in this manner is simply a measure of the total number of offspring, not how capable one is of conceiving.

I found these sources in 15m of searching. I'm sure you can find many more with concentrated effort. Open up any article and refer to their references for a start.

Sources:

  • Campbell, C., & Preston, S. (1993). Differential fertility and the distribution of traits: the case of IQ. The American Journal of Sociology, 98(5), 997+.
  • Gelade, G. A. (2008). The geography of IQ. Intelligence, 36, 495-501.
  • Harvey, J., & Lynn, R. (2008). The decline of the world's IQ. Intelligence, 36(2), 112+.
  • Hondroyiannis, G., & Papapetrou, E. (2005). Fertility and output in Europe: new evidence from panel cointegration analysis. Journal of Policy Modeling, 27, 143-156.
  • Loehlin, J. C. (1997). Dysgenesis and IQ: What Evidence Is Relevant?. American Psychologist, 52(11), 1236-1239.
  • Lynn, R., & Jarvey, J. (2008). The decline of the world's IQ. Intelligence, 36, 112-120.
  • Lynn, R., & Van Court, M. (2004). New evidence of dysgenic fertility for intelligence in the United States. Intelligence, 32, 193-201.
  • Meisenberg, G. (in press). National IQ and economic outcomes. Personality and Individual Differences.
  • Meisenberg, G. (2010). The reproduction of intelligence. Intelligence, 38(2), 220+.
  • Preston, S. H., & Campbell, C. (1993). Differential fertility and the distribution of traits: the case of IQ. American Journal of Sociology, 98(5), 997-1019.
  • Redwood, A. L. (1983). An economic-demographic approach to forecasting national and subnational birth rates. Socio-Economic Planning Sciences, 17(5-6), 355-363.
  • Reeve, C. L. (2009). Expanding the g-nexus: Further evidence regarding the relations among national IQ, religiosity and national health outcomes. Intelligence, 37(5), 495-505.
  • Retherford, R. D., & Sewell, W. H. (1989). How intelligence affects fertility. Intelligence, 13(2), 169-185.
  • Retherford, R. D., & Sewell, W. H. (1988). Intelligence and family size reconsidered. Biodemography and Social Biology, 35(1-2), 1-40.
  • Shatz, S. M. (2008). IQ and fertility: A cross-national study. Intelligence, 36(2), 109.
  • Van Court, M., & Bean, F. D. (1985). Intelligence and fertility in the United States: 1912–1982. Intelligence, 9(1), 23-32.
  • Vining, D. R., Bygren, L., Hattori, K., Nystrom, S., & Tamura, S. (1988). IQ/fertility relationships in Japan and Sweden. Personality and Individual Differences, 9(5), 931-932.
  • Vining, D. R. (1982). On the possibility of the reemergence of a dysgenic trend with respect to intelligence in American fertility differentials. Intelligence, 6(3), 241-264.
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    Welcome to Skeptics! We expect answers to provide references for all significant claims they make. I'm curious about that statistic you mention as I suspect it would be extremely hard to correct for confounding factors. – Mad Scientist Aug 21 '11 at 7:20
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    +1 Roger that Fabian. I didn't realize this was a "significant" claim, as you put it. Is there a definition of "significant" somewhere? For example: I think the center of the Sun is not made of ice cream. Would I have to cite that? I think Evolution by natural selection is a valid theory in explaining the diversity of life on Earth. Would I have to cite that? Both appear to be "obvious", in some regard, but vary drastically in the amount of evidence for each. Just trying to wrap my head around what is required to cite and what is not. Thanks! :) – stoicfury Aug 21 '11 at 17:00
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    Please add quotes from some of your relevant sources. Good answers here will quote the relevant material so we don't have to take your word for it! I also agree with Fabian that it would be good to see that the studies have at least attempted to correct for some of the confounding factors. – John Lyon Aug 22 '11 at 1:27
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    @stoicfury, the rule-of-thumb is whether it would be known by high school science student. Obviously, that still leaves a lot of grey area. – Oddthinking Aug 22 '11 at 2:39
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    @stoicfury Providing a list of references is not enough. You should also quote relevant parts here so that anyone can check quickly and easily what the sources say about the subject. I know it is tough, and it is unusual, but this is how it works here. Visit meta if you want to check why or to discuss the policies. – Suma Sep 21 '11 at 5:54

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