Balls and brains -- Smart men have better sperm
economist.com
economist.com
And what does the finding necessarily have to do with genetics, except in the frenzied minds of the genetically obsessed?
From the article:
Hitherto, biologists have tended to disaggregate the idea of fitness into a series of adaptations that are more or less independent of each other. This work adds to the idea of a general fitness factor, f, that is similar in concept to g—and of which g is one manifestation.
This is the obvious, dressed up as insight and deployed against a pitiful straw man. Biologists have certainly known, as everyone knows, that aspects of fitness are not "more or less independent of each other": My sperm count, my brain function, my ability to win an arm-wrestling competition, and my tendency to resist getting colds are scarcely independent of my diet or my exercise. (Which, indeed, means that they are scarcely independent of my parents' skill at earning money or my society's skill at storing food to sustain itself through droughts.)
Better insights, please. Or, perhaps, better journalism.
It is unfortunate that an article talking about intelligence starts with a tautology.
B = You are intelligent
In logic, the argument translates to :
A <=> B (quality of sperm depends on your intelligence), B <=> A (and vice versa, intelligence depends on your quality of sperm)
<=> is a connector wich means "A is true if and only if B is true". Therefore, you have a good sperm if and only if you are intelligent, wich is the logical twin of "you are intelligent if and only if you have a good sperm". It is a tautology because the 2 expressions are equivalent and the meaning of the first is included in the second.
Even if it sounds superfluous, this kind of exercice actually helps you to spot the weakness of this study, because it logically excludes any other parameter than intelligence to determine successfuly the quality of sperm (depends can be translated to "is a function of"). <=> is a very strong connector. In their study, men with low intelligence and a good quality of sperm don't exist, neither do highly intelligent men wich poor sperm, then they draw conclusions. Wich is convenient, but dumb.
How did you come to that conclusion?
I hope this isn't true, because if sexual selection is the cause of human intelligence, this means that American men are slowly turning into illiterate redneck bikers with excellent "game".
Foreign ladies FTW.
In the realm of intelligence, cultural progress (which encompasses better education, nutrition, technology, and everything else) has led to the Flynn effect, a gain of 3-5 IQ points per decade. Biological evolution in Homo sapiens has given us at most 100 IQ points (but probably closer to 50) in the last 74,000 years. The former is three orders of magnitude faster!
The Flynn effect itself will probably stop or slow all-but-completely anyway
Evolution slowly created a biological basis for the maximum life span/intelligence (including genetics-based variability with relatively few individuals able to achieve extremes).
Cultural progress just allowed more people to: a) live longer up to their genetic maximum, b) be smarter up to their genetic maximum. Thus it shifted the averages but not the extremes.
Flynn effect seems to support this: gains in IQ predominantly occur at the low end of the distribution.
See also discussion on iodine deficiency, it's the same principle:
How did you come to believe that there could be such a thing as a genetic maximum to phenotypic traits?