Here is a fascinating article from The New Yorker, mostly about itching but not just.  Here is my favorite part:

A new scientific understanding of perception has emerged in the past few decades, and it has overturned classical, centuries-long beliefs about how our brains work–though it has apparently not penetrated the medical world yet. The old understanding of perception is what neuroscientists call “the naïve view,” and it is the view that most people, in or out of medicine, still have. We’re inclined to think that people normally perceive things in the world directly. We believe that the hardness of a rock, the coldness of an ice cube, the itchiness of a sweater are picked up by our nerve endings, transmitted through the spinal cord like a message through a wire, and decoded by the brain.

…Yet, as scientists set about analyzing the signals, they found them to be radically impoverished. Suppose someone is viewing a tree in a clearing. Given simply the transmissions along the optic nerve from the light entering the eye, one would not be able to reconstruct the three-dimensionality, or the distance, or the detail of the bark–attributes that we perceive instantly.

…The images in our mind are extraordinarily rich. We can tell if something is liquid or solid, heavy or light, dead or alive. But the information we work from is poor–a distorted, two-dimensional transmission with entire spots missing. So the mind fills in most of the picture. You can get a sense of this from brain-anatomy studies. If visual sensations were primarily received rather than constructed by the brain, you’d expect that most of the fibres going to the brain’s primary visual cortex would come from the retina. Instead, scientists have found that only twenty per cent do; eighty per cent come downward from regions of the brain governing functions like memory. Richard Gregory, a prominent British neuropsychologist, estimates that visual perception is more than ninety per cent memory and less than ten per cent sensory nerve signals.

And sorry, readers, for shouting in the header; sometimes I get carried away.  By the way, don’t let defenders of naive realism tell you that any attempt to contradict it is self-refuting.  Science proceeds in pieces, cross-tested in various ways, and the sum total of those pieces can revise our understanding away from naive realism without producing self-contradiction.

In reference to my Bloggingheads appearance, one loyal MR reader emails me:

you said don’t be certain, be 90-10 or 60-40 then [you] said 1-99 that humanity dies out when sun’s gone.

Yes, I believe the chance is very small that humanity survives the death of our sun or even gets close to that point.  I’ll give it p = .005.  But what’s the chance I think that is the correct p or even in the neighborhood of the correct p?  Maybe 60 percent.  Of course my p estimate could go either up or down and after I apply meta-rationality p = .005 is where I end up, for better or worse.  I expect that fragile estimate to undergo lots of revision as I age, read more, etc.  I just don’t know if it will go up or down, thereby satisfying one of Robin Hanson’s canons of rationality (or some approximation thereof).

Why am I skeptical?  The Fermi paradox, for one thing, plus I observe that humans aren’t very good at solving large-scale collective action problems.  Our environment may be more fragile than we had thought and that’s without even considering the impact of man.

Under one scenario, the shy become more extroverted and everyone enjoys their new bon mots and witty asides.  Gains from trade increase all around.  Under another scenario, shyness and extroversion are part of a larger positional game.  Some people take the anti-shyness drug, but the previous extroverts, facing new competition for sex and friends, become even more extroverted, thus feeling more strain.  Many of them start taking the drug to stay ahead.  The previously shy exhibit more "juice," so to speak, but without much net result in terms of an improved life since they are still coming in second, so to speak.  And those who don’t take the anti-shyness drug are even worse off than before, given the new and higher standard for extroversion.

Some of the remaining shy, however, might in fact feel relieved.  If the new standard of extroversion rises so high that they can’t possibly meet it, they might, to some extent, withdraw from social competition.  The truly shy might even form social clubs and band together in the interests of promoting shyness.  If they can signal that they do not take the drug, their shyness might become more socially acceptable than before.