Balls and brains -- Smart men have better sperm

http://www.economist.com/science/displayStory.cfm?story_id=12719355

by dzohrob • 18 years ago

18 15 18 years ago

In the ensuing arms race to show off and get a mate it has been exaggerated in the way that a peacock’s tail is. This process of sexual selection, Dr Miller and his followers believe, is the reason people have become so brainy.

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.

gcheong• 18 years ago

Things like this always remind me of the movie Idiocracy of which the first 10min or so is best part:

http://www.imdb.com/title/tt0387808/

smanek• 18 years ago

http://video.google.com/videoplay?docid=1597642154209383351

randomwalker• 18 years ago

Were you trying to be funny (if so, a smiley would help a lot), or do you not get that evolution works on a different time scale? Cultural evolution has dramatically outpaced biological evolution in humans in the last millenium, making the latter irrelevant.

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!

mynameishere• 18 years ago

Nutrition, Education, etc, have continual costs. If we have a continuously dropping natural intelligence, then the part of our intelligence derived from the environment will only get more expensive. That's unsustainable.

The Flynn effect itself will probably stop or slow all-but-completely anyway

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi...

bd• 18 years ago

From my understanding, recent IQ gains are more akin to recent increases of the life expectancy.

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:

http://news.ycombinator.com/item?id=386449

peakok2• 18 years ago

The quality of a man’s sperm depends on how intelligent he is, and vice versa

It is unfortunate that an article talking about intelligence starts with a tautology.

tyn• 18 years ago

Why is this a tautology?

peakok2• 18 years ago

A = You have a good sperm

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.

mechanical_fish• 18 years ago

So what exactly is so interesting about this study? Is it supposed to be astonishing that the function of my brain and the function of... the rest of my body are correlated? That if you starve one you starve the other? That if you do exercises to improve the circulation of one, you improve the circulation of the other? That if you get better sleep and avoid stress both of these things will improve?

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.

danteembermage• 18 years ago

Suppose person A has nuturing parents as a child. Nurturing parents encourage study and hard work leading to higher IQ as an adult. Moreover, nurturing parents feed their children nutritious food and no matter how many cigarettes or calories I consume as an adult I still had good nutrition when my brain (and sperm) were developing. I don't think their experimental design precludes this, although looking at sperm health does have the advantage that it's less likely to be influenced by decisions as an adult.

opticksversi2• 18 years ago

study and hard work [lead] to higher IQ as an adult.

How did you come to that conclusion?

callmeed• 18 years ago

So, that's why my wife gets pregnant so easy ...

mmmm4• 18 years ago

No way! you do not necessarily believe the "brainism," (similarly, racism, or any other types of "-ism", like socialism, etc.) however, I still like to believe in the theory of Darwinism, especially social Darwinism ... Of course, in order to be accepted as a "theory," it needs to have proofs. I am not a scientist, I am just speaking in a layman language.

Balls and brains -- Smart men have better sperm

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