This isn't a peer-reviewed journal, so sometimes I forget things, or only think of them later but don't bother re-publishing the post, etc. So just some additions / revisions to 3 science posts -- on recent selection, beauty vs sublime, and genius germs.
On More recent selection
, in the comments, tossed out Jerry Pournelle's
idea that domestication of the dog loosened the functional constraint on genes giving us a good sense of smell, thus freeing up brain real estate for increased general intelligence. This is akin to, say, the cortical area devoted to smell shrinking in the primate lineage, and an expansion of area devoted to vision, as we began to rely less on the former and more on the latter to survive & reproduce.
I'd been thinking about a more general relaxation of functional constraint after the dawn of civilization -- namely, the more you rely on other things (other humans, dogs, gut flora, technology, etc.), the less you have to do yourself. You outsource the tasks to other people. You're outsourced to as well, so you can't lose all sense of smell (or whatever), but you're just one cog in a big machine that doesn't demand as much of any arbitrary individual. Now that all those other things are doing just about everything for you but wiping your ass, the systems devoted to higher reasoning (for example) can expand and play a larger role in determining who will sire the most progeny. So, civilized people will get smarter.
On Psychometrics and evolutionary aesthetics
I posited that the two component vectors of an individual's "aesthetic preference" score were an appreciation for danger and for beauty. These were assumed to reflect, respectively, our intuitive responses to things that over evolutionary time would've threatened fitness, and those that would've promoted it. I didn't have a good reason for using two components as opposed to a single axis with threatens vs promotes fitness -- just the observation that two seemed to work better than one in accounting for reality.
It later struck me that that's how the autonomic division
of the nervous system works: there is the sympathetic
sub-division that deals with responses to real or perceived threats or crises (fight, flight, fright, and orgasm), and the parasympathetic
sub-division that deals with homeostasis or being in a relaxed state (digestion, slowing heart beat, etc.). It's transparent how the danger vector from my graph maps onto activation of the sympathetic system. While less transparent, most aesthetic theories both classical and modern intertwine the ideas of beauty with those of order, harmony, proper proportion, and so on -- that is, the state of things being calm rather than disturbed. Maybe I should re-label the axes harmony
So, our "aesthetic preference" is parasitic off of our more basic systems that prepare the body for both threats and relaxation (for lack of a better word). The broad approach & particular experiments I suggested still hold, though -- the idea is that "aesthetic value" is a general factor that holds across diverse domains, so if an individual prefers to artificially stimulate their sympathetic system in the area of sports (i.e., prefers riskier, more thrilling sports), then they would prefer to do so in listening to music (i.e., more turbulent music) and in sexual matters (i.e., kinkier preferences). Likewise for someone who preferred to stimulate their parasympathetic system, or for someone who preferred to stimulate both -- that's hard to accomplish in reality, since the systems are complementary, but we're talking about a person's preferences, whether or not they can realize them.
Last, on the Genius Germs
series (graphs here
Most importantly, there was a lot of griping in comments here & at GNXP over the idea that there might be a brain counterpart of the gut flora which could boost intelligence, just as the gut flora boost digestive power. I still believe, on (informed) faith, something like that exists, but these data don't necessarily argue in favor of that. The reason is that aside from superior intelligence, genius-level creativity is also a product of at least two other factors: some degree of psychoticism
personality (according to Eysenck, Rushton, Simonton, among others) and perhaps Openness
to experience from the Big Five personality inventory (as Simonton and Gottfredson have suggested).
Therefore, my "genius germs" may affect these personality factors rather than the intelligence factor in making someone into a Newton or a Beethoven. At least, that's the simplest interpretation, given that the parts of the brain involved in personality & motivation are less protected by the Brain-Blood Barrier, are expected to be targeted
more than higher reasoning centers by microbes, and have more evidence in favor of them -- for example, the high likelihood (on epidemiological & evolutionary grounds) that schizophrenia is infectious. So, I still believe, but cannot prove, that there are brain flora that help overall function, though I'm now convinced that at the highest level of genius, those guys were nuts due to infection. 
And uh, like, a-duh -- a significance test would've been nice. The trend was clear, but nailing down the p-value is of course always called for. Collapsing the data from the all graphs, excluding Combined Sciences (that is, considering all
science inventories, in addition to the arts, mostly to increase the N), we get the following contingency table, where WS = winter-spring birth, SF = summer-fall birth, G = genius (top 5 deciles), BG = below genius (otherwise):
---- WS -- SF -- Tot
G __41 __21 __62
BG _336 _299 _635
Tot _377 _320 _697
The expected values for the G row are both 31; for the BG row, 317.5. Using a G-test
with df = 1, G = 8.73, or p less than .004. Again, most of that high G value comes from the lopsidedness in the Genius row, not the Below Genius row.
Now, for the three most abstract fields (Music in the arts, Mathematics in the sciences, Philosophy in the humanities), the expected values in the cells of the Genius row were low (7.5), so I had to do a more laborious Fisher's exact test
. The labels are as above, but the data represent only the three most abstract fields now:
---- WS -- SF -- Tot
G __13 __2 ___15
BG _83 __60 __143
Tot _96 _62 ___158
There are three scenarios that are as extreme or more than the observed scenario -- the observed itself, and where the G-SF cell is either 1 or 0 (indicating even greater lopsidedness toward winter-spring geniuses). The p values for the cases where the G-SF cell = 2, 1, and 0 are, respectively: p = .02, .004, .0004. Summing those up gives overall p = .0244, which is less than .03, hence significant.
 I looked more into the "lack of Vitamin D" angle that several folks mentioned, but the historical trend of prevalence of rickets didn't match up w/ the historical trend of creative production as documented in Human Accomplishment
. Perhaps, as one commenter suggested, the Vitamin D connection is w/ the mother's health -- i.e., if you were born in winter or spring, your mother would've received more Vitamin D while you were still a fetus. There's evidence that vitamins matter for IQ, but having more Vitamin D doesn't make someone crazy. So, combining both insights -- being born in winter-spring means that: 1) your mother got more Vitamin D when you were developing, thus fostering higher IQ; and 2) you were later exposed to more microbes during infancy, fostering a nutty & eccentric personality.