
Balls and brains -- Smart men have better sperm - dzohrob
http://www.economist.com/science/displayStory.cfm?story_id=12719355
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mechanical_fish
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.

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peakok
_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
Why is this a tautology?

~~~
peakok
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.

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danteembermage
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.

~~~
opticksversi
_study and hard work [lead] to higher IQ as an adult._

How did you come to _that_ conclusion?

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mmmm4
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.

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

------
time_management
_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.

~~~
randomwalker
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!

~~~
bd
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>

~~~
opticksversi
_Cultural progress just allowed more people to: a) live longer up to their
genetic maximum, b) be smarter up to their genetic maximum._

How did you come to believe that there could be such a thing as a _genetic
maximum_ to phenotypic traits?

