Monday, November 17, 2008

Ignorance Is Bliss

Having written twice about the dangers of believing everything you are told, I'd like to give some face time to the opposing argument:

Ignorance is bliss.

It's all well and good to say, "You should understand things, not just follow blindly." But to be pragmatic, there is only one time this is a serious improvement: when the blind belief is wrong. What about the times that blind belief is right? Humans survived for centuries without understanding how gravity truly worked and that didn't stop them from creating some awesome things. They were even able to use the fact that "things fall towards the ground" to great effect, such as building water clocks, without ever learning Kepler's laws of motion.

Even if someone did want to totally understand the world today, it wouldn't be possible. There is such a vast corpus of information that learning even 1% of it is literally impossible in the span of a human life. Mathematicians who are experts in their field rarely have the chance to keep up on other branches of mathematics, to say nothing of physics, chemistry, or medicine.

The fact of the matter is that most of the information we've been told is correct. If I get a bus that says "Downtown" as its destination, it really is going there. The driver could take it anywhere but I'm very certain that the destination is downtown. When I order a meal at a restaurant, I take it for granted that the cook can actually make the things on the menu and that I'll be served food that's reasonable close to the description provided. The waitress serves me food assuming that I will pay the price listed. I suspect that less than 1 in 10,000 people really understands what a computer does when you turn it on, but hundreds of millions of people use a computer every day. Understanding is a luxury, not a necessity.

Like it or not, our lives as humans are anchored in faith, not reason and understanding, and this is the cornerstone of the religion well all share: Causality. If we do something ten times in a row and got the same result, we expect that the eleventh time will produce the same result. And it does, even though we rarely know why. Understanding everything is impossible, and the whole purpose of culture is to provide structure so that everyone can use the discoveries other people made.

If that's the case, why bother thinking about anything at all? Why not let someone else do your thinking for you? The primary purpose of education isn't to give people information, but to teach them how to think. And most importantly, to teach them when to think. Thinking is really important in uncharted waters. In any situation that doesn't match your typical life experience, thinking will give you a much better idea of what to do than trying something at random.

Unsurprisingly, the same problem comes up in artificial intelligence. There's only so much processor time to go around. So if seven bots all need the same piece of information and they will all come to roughly the same conclusion, it's much faster to do a rough computation once and let them all use those results. This leads to an information dichotomy, where there's general "AI Information" and "Bot specific information". Each bot has its own specific information, but shares from the same pool of general information. In BrainWorks, all bots share things like physics predictions and the basic estimation of an item's value. If a player has jumped off a ledge, there's no reason for every bot to figure out when that player will hit the bottom. It's much faster to work it out once (the first time a bot needs to know) and if another bot needs to know, it can share the result.

These are the kinds of optimizations that can create massive speed improvements, making an otherwise difficult computation fast. If you think about it, it's not that different from one person researching the effects of some new medicine and then sharing the results with the entire world.

1 comment:

Dave Mark said...

Heh... you are really going to dig my book, "Behavioral Mathematics for Game AI" when it comes out in March. ;-)

Chapter 6: "Rational and Irrational Behavior"... specifically the sections titled "Bounded Rationality" and "Rational Ignorance"

BTW, are you going to GDC?