August 28, 2008

Harder Choices Matter Less

...or they should, logically speaking.

Suppose you're torn in an agonizing conflict between two choices.

Well... if you can't decide between them, they must be around equally appealing, right?  Equally balanced pros and cons?  So the choice must matter very little - you may as well flip a coin.  The alternative is that the pros and cons aren't equally balanced, in which case the decision should be simple.

This is a bit of a tongue-in-cheek suggestion, obviously - more appropriate for choosing from a restaurant menu than choosing a major in college.

But consider the case of choosing from a restaurant menu.  The obvious choices, like Pepsi over Coke, will take very little time.  Conversely, the choices that take the most time probably make the least difference.  If you can't decide between the hamburger and the hot dog, you're either close to indifferent between them, or in your current state of ignorance you're close to indifferent between their expected utilities.

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July 31, 2008

Detached Lever Fallacy

Followup toHumans in Funny Suits

This fallacy gets its name from an ancient sci-fi TV show, which I never saw myself, but was reported to me by a reputable source (some guy at an SF convention).  Anyone knows the exact reference, do leave a comment.

So the good guys are battling the evil aliens.  Occasionally, the good guys have to fly through an asteroid belt.  As we all know, asteroid belts are as crowded as a New York parking lot, so their ship has to carefully dodge the asteroids.  The evil aliens, though, can fly right through the asteroid belt because they have amazing technology that dematerializes their ships, and lets them pass through the asteroids.

Eventually, the good guys capture an evil alien ship, and go exploring inside it.  The captain of the good guys finds the alien bridge, and on the bridge is a lever.  "Ah," says the captain, "this must be the lever that makes the ship dematerialize!"  So he pries up the control lever and carries it back to his ship, after which his ship can also dematerialize.

Similarly, to this day, it is still quite popular to try to program an AI with "semantic networks" that look something like this:

(apple is-a fruit)
(fruit is-a food)
(fruit is-a plant)

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July 30, 2008

Humans in Funny Suits

Biggornandkirk_2Followup toThe Psychological Unity of Humankind

Many times the human species has travelled into space, only to find the stars inhabited by aliens who look remarkably like humans in funny suits - or even humans with a touch of makeup and latex - or just beige Caucasians in fee simple.

It's remarkable how the human form is the natural baseline of the universe, from which all other alien species are derived via a few modifications.

What could possibly explain this fascinating phenomenon?  Convergent evolution, of course!  Even though these alien lifeforms evolved on a thousand alien planets, completely independently from Earthly life, they all turned out the same.

Don't be fooled by the fact that a kangaroo (a mammal) resembles us rather less than does a chimp (a primate), nor by the fact that a frog (amphibians, like us, are tetrapods) resembles us less than the kangaroo.  Don't be fooled by the bewildering variety of the insects, who split off from us even longer ago than the frogs; don't be fooled that insects have six legs, and their skeletons on the outside, and a different system of optics, and rather different sexual practices.

You might think that a truly alien species would be more different from us than we are from insects - that the aliens wouldn't run on DNA, and might not be made of folded-up hydrocarbon chains internally bound by van der Waals forces (aka proteins).

As I said, don't be fooled.  For an alien species to evolve intelligence, it must have two legs with one knee each attached to an upright torso, and must walk in a way similar to us.  You see, any intelligence needs hands, so you've got to repurpose a pair of legs for that - and if you don't start with a four-legged being, it can't develop a running gait and walk upright, freeing the hands.

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June 28, 2008

Average Your Guesses

What percentage of the world’s airports are in the USA? (Answer below the fold.)

Take a guess. Now, take another guess, different from the first one, and average them. According to research reported on in The Economist, averaging the 2nd guess improves accuracy by 6.5%. Better still, wait 3 weeks before taking a second guess. Averaging now improves accuracy by 16%. (Story found via Slashdot.)

Here is the full report from Pschological Science.  Some excerpts:

It is important that neither group knew they would be required to furnish a second guess, as this precluded subjects from misinterpreting their task as being to specify the two endpoints of a range.

That could make it a little tricky to do this on your own; you have to try to make your first guess as good as you can, and then start fresh for the second guess.

This benefit of averaging cannot be attributed to subjects' finding more information between guesses, because second guesses were less accurate than first guesses

Hmmm, how can second guesses be less accurate than first guesses, yet averaging them is more accurate than either? I suppose it means that the two guesses tend (on average) to bracket the correct answer, with the second guess farther away than the first one. That means that your first instinct to improve your guess is more likely than not to be in the correct direction, but go too far. Knowing this might allow you to improve your guesses even more.

Oh, and as for the airports? According to the CIA World Factbook, there are 14,947 airports in the U.S., and 49,024 in the whole world, so 30% of the world's airports are in the U.S. For the record, I guessed 25%, and then 15%, so averaging didn't help me. But in general this might be a useful trick to easily improve guesses.

June 27, 2008

2-Place and 1-Place Words

Monsterwithgirl_2

Followup toThe Mind Projection Fallacy, Variable Question Fallacy

I have previously spoken of the ancient, pulp-era magazine covers that showed a bug-eyed monster carrying off a girl in a torn dress; and about how people think as if sexiness is an inherent property of a sexy entity, without dependence on the admirer.

"Of course the bug-eyed monster will prefer human females to its own kind," says the artist (who we'll call Fred); "it can see that human females have soft, pleasant skin instead of slimy scales.  It may be an alien, but it's not stupid - why are you expecting it to make such a basic mistake about sexiness?"

What is Fred's error?  It is treating a function of 2 arguments ("2-place function"):

Sexiness: Admirer, Entity -> [0, ∞)

As though it were a function of 1 argument ("1-place function"):

Sexiness: Entity -> [0, ∞)

If Sexiness is treated as a function that accepts only one Entity as its argument, then of course Sexiness will appear to depend only on the Entity, with nothing else being relevant.

When you think about a two-place function as though it were a one-place function, you end up with a Variable Question Fallacy / Mind Projection Fallacy.  Like trying to determine whether a building is intrinsically on the left or on the right side of the road, independent of anyone's travel direction.

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June 26, 2008

No Universally Compelling Arguments

Followup toThe Design Space of Minds-in-General, Ghosts in the Machine, A Priori

What is so terrifying about the idea that not every possible mind might agree with us, even in principle?

For some folks, nothing - it doesn't bother them in the slightest. And for some of those folks, the reason it doesn't bother them is that they don't have strong intuitions about standards and truths that go beyond personal whims.  If they say the sky is blue, or that murder is wrong, that's just their personal opinion; and that someone else might have a different opinion doesn't surprise them.

For other folks, a disagreement that persists even in principle is something they can't accept.  And for some of those folks, the reason it bothers them, is that it seems to them that if you allow that some people cannot be persuaded even in principle that the sky is blue, then you're conceding that "the sky is blue" is merely an arbitrary personal opinion.

Yesterday, I proposed that you should resist the temptation to generalize over all of mind design space.  If we restrict ourselves to minds specifiable in a trillion bits or less, then each universal generalization "All minds m: X(m)" has two to the trillionth chances to be false, while each existential generalization "Exists mind m: X(m)" has two to the trillionth chances to be true.

This would seem to argue that for every argument A, howsoever convincing it may seem to us, there exists at least one possible mind that doesn't buy it.

And the surprise and/or horror of this prospect (for some) has a great deal to do, I think, with the intuition of the ghost-in-the-machine - a ghost with some irreducible core that any truly valid argument will convince.

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June 25, 2008

The Design Space of Minds-In-General

Followup toThe Psychological Unity of Humankind

People ask me, "What will Artificial Intelligences be like?  What will they do?  Tell us your amazing story about the future."

And lo, I say unto them, "You have asked me a trick question."

ATP synthase is a molecular machine - one of three known occasions when evolution has invented the freely rotating wheel - which is essentially the same in animal mitochondria, plant chloroplasts, and bacteria.  ATP synthase has not changed significantly since the rise of eukaryotic life two billion years ago.  It's is something we all have in common -  thanks to the way that evolution strongly conserves certain genes; once many other genes depend on a gene, a mutation will tend to break all the dependencies.

Any two AI designs might be less similar to each other than you are to a petunia.

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June 24, 2008

The Psychological Unity of Humankind

Followup toEvolutions Are Stupid (But Work Anyway), Evolutionary Psychology

Biological organisms in general, and human brains particularly, contain complex adaptations; adaptations which involve many genes working in concert. Complex adaptations must evolve incrementally, gene by gene.  If gene B depends on gene A to produce its effect, then gene A has to become nearly universal in the gene pool before there's a substantial selection pressure in favor of gene B.

A fur coat isn't an evolutionary advantage unless the environment reliably throws cold weather at you.  And other genes are also part of the environment; they are the genetic environment.  If gene B depends on gene A, then gene B isn't a significant advantage unless gene A is reliably part of the genetic environment.

Let's say that you have a complex adaptation with six interdependent parts, and that each of the six genes is independently at ten percent frequency in the population.  The chance of assembling a whole working adaptation is literally a million to one; and the average fitness of the genes is tiny, and they will not increase in frequency.

In a sexually reproducing species, complex adaptations are necessarily universal.

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June 22, 2008

Surface Analogies and Deep Causes

Followup toArtificial Addition, The Outside View's Domain

Where did I acquire, in my childhood, the deep conviction that reasoning from surface similarity couldn't be trusted?

I don't know; I really don't.  Maybe it was from S. I. Hayakawa's Language in Thought and Action, or even Van Vogt's similarly inspired Null-A novels.  From there, perhaps, I began to mistrust reasoning that revolves around using the same word to label different things, and concluding they must be similar?  Could that be the beginning of my great distrust of surface similarities?  Maybe.  Or maybe I tried to reverse stupidity of the sort found in Plato; that is where the young Eliezer got many of his principles.

And where did I get the other half of the principle, the drive to dig beneath the surface and find deep causal models?  The notion of asking, not "What other thing does it resemble?", but rather "How does it work inside?"  I don't know; I don't remember reading that anywhere.

But this principle was surely one of the deepest foundations of the 15-year-old Eliezer, long before the modern me.  "Simulation over similarity" I called the principle, in just those words.  Years before I first heard the phrase "heuristics and biases", let alone the notion of inside views and outside views.

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June 20, 2008

Heading Toward Morality

Followup toGhosts in the Machine, Fake Fake Utility Functions, Fake Utility Functions

As people were complaining before about not seeing where the quantum physics sequence was going, I shall go ahead and tell you where I'm heading now.

Having dissolved the confusion surrounding the word "could", the trajectory is now heading toward should.

In fact, I've been heading there for a while.  Remember the whole sequence on fake utility functions?  Back in... well... November 2007?

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