The correlation is quite small, but interesting nevertheless. I tried looking for replication studies, but couldn't find any.<p>Here is the publication in question: <a href="http://www.udel.edu/educ/gottfredson/reprints/2009semen.pdf" rel="nofollow">http://www.udel.edu/educ/gottfredson/reprints/2009semen.pdf</a><p>Here is an addendum trying to explain why it might be the case: <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2775227/" rel="nofollow">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2775227/</a>
Alternative theory: men think with their junk. OK, I'll see myself out...<p>In all seriousness, it'd be great to see a more thorough study here. I see so many confounding factors. Measuring intelligence is a tough one. Perhaps people more likely to score higher on intelligence tests come from a part of the world where higher sperm counts were selected for genetically. For example, how do sperm counts correlated with the number of cold vs hot days during an average year? Or humidity levels? Or circumcision traditions? Or average penis size? My point is that there are so many factors that go into calculating intelligence and at least to me it seems there are as many factors that affect sperm count that this correlation may be influenced by several other hidden variables.
If this would be true, we'd already live here: <a href="https://en.wikipedia.org/wiki/Idiocracy" rel="nofollow">https://en.wikipedia.org/wiki/Idiocracy</a>
my understanding is that transmitting intelligence to the next generation requires (a) the presence of whatever genes are responsible for intelligence and (b) the absence of mutations affecting those genes.<p>it would make sense that the quality of sperm correlates with intelligence, because it would have to be less damaged in order to reliably transmit these attributes. the headline seems to dance around this, perhaps because of the controversy involved.<p>one unfortunate factor which affects the quality of sperm - paternal age. average number of mutations increase every year. so if you're "thinking" about starting a family, consider that a disincentive to wait.
"They may, for example, be less likely to smoke, more likely to eat healthy foods or to exercise, and so on." I would chalk up the small correlation documented to this. Higher IQ people tend to be higher on the social scale and be healthier in a large variety of ways.
This is very significant. If human <i>general</i> intelligence was just a coincidence of runaway sexual selection, then what are the chances of that occurring again on a different planet? How many times have peacocks independently evolved?
So i can't still figure it out..<p>Smart guy --> better sperm or
Better sperm --> smart guy<p>maybe my sperm is telling me something with this question.
"Quality of a man’s sperm depends on how intelligent he is, and vice versa"<p>I don't think people know what "depends" means anymore. Especially the "vice versa" part.<p>That means if you improve the quality of your sperm, as a direct consequence you <i>will</i> become more intelligent, which brings forward all kinds of interesting questions, such as do men <i>really</i> think with their balls?