Also, encryption is easy; key management is hard. If your workplace sets up a Public Key Infrastructure on your Exchange server, all you have to do is click "encrypt." But outside of an organization that uses it, you'll need some out-of-band way of exchanging keys with everyone you want to communicate with. And, as fun as key-signing parties are, they can be a little awkward for, say, someone you just met on reddit.

...which I think is about 6 months away...

Outside view suggests it might be more like a year. (Ants was originally planned--at least by one of the contest's officials--for about 6 months after planet wars.)

I'm not too unhappy with my #326 finish, considering that life intervened and I basically didn't work on it at all for the second half of the contest. Percentage-wise, it's an improvement over the last one, anyway. I was also struck by how mundane the winner's strategy was (http://www.xathis.com/posts/ai-challenge-2011-ants.html). It seems he didn't beat it with just a few overarching principles, but rather a lot of little pieces done well.

I have some more postmortem thoughts that I'll try to write down in a bit.

While we're talking about this: does anyone know why encryption isn't standard? What advantage is there in communicating with someone without encryption?

There's a similar guideline in the software world:

There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult.

FWIW, there's a nice proof of Bayes' theorem in Russel and Norvig's textbook, which I haven't seen posted here yet.

That was interesting, thanks. Here's another take - specific to the field of language modeling, but addresses the same question of statistical versus formal models: http://norvig.com/chomsky.html

Okay, so, how did this survive evolution?

There is variation in the population over tolerance for risk. If the preference for certainty is detrimental in achieving goals, then those with less attachment to certainty, ceteris paribus, would have better overall reproductive success than the ones with greater attachment. Accordingly, a pro-certainty bias would be selected against.

So, what's the reason it didn't get selected out of the population?

This reminds me of Explain/Worship/Ignore. Am I getting the right idea?

Study cognitive biases and fallacies and use them to examine your thought patterns and actions. Cognitive dissonance is, in my opinion, the most important, as it allows people to make mistakes without recognizing them as such and thus to make them again and again. Every time you make a decision that has unexpected consequences, even if they are favorable, ask yourself honestly, was this really a good decision? What evidence did you have at the time to justify it? Would you make it again, and if so, why? Would other people agree with your reasoning?

People can go through life blissfully unaware of how catastrophically bad some of their past decisions--for example, of where to work, where to live, who to marry--have been because of this all-power cognitive bias. Your goal is not to obsess over the past (and there is a risk of that), but rather to learn from it, and cognitive dissonance impedes you from doing that.