To break up the awkward silence at the start of a recent Overcoming Bias meetup, I asked everyone present to tell their rationalist origin story - a key event or fact that played a role in their first beginning to aspire to rationality. This worked surprisingly well (and I would recommend it for future meetups).
I think I've already told enough of my own origin story on Overcoming Bias: how I was digging in my parents' yard as a kid and found a tarnished silver amulet inscribed with Bayes's Theorem, and how I wore it to bed that night and dreamed of a woman in white, holding an ancient leather-bound book called Judgment Under Uncertainty: Heuristics and Biases (eds. D. Kahneman, P. Slovic, and A. Tversky, 1982)... but there's no need to go into that again.
So, seriously... how did you originally go down that road?
Added: For some odd reason, many of the commenters here seem to have had a single experience in common - namely, at some point, encountering Overcoming Bias... But I'm especially interested in what it takes to get the transition started - crossing the first divide. This would be very valuable knowledge if it can be generalized. If that did happen at OB, please try to specify what was the crucial "Aha!" insight (down to the specific post if possible).
Hi everyone. Just to note from the beginning of this comment, I'm a bit different from the typical LW demographic, so maybe this will help shed light on another way of coming to rationalism.
I was born into a mildly Jewish agnostic household, but when I was about 4, I became strongly drawn to Christianity. I didn't know much about it, but I somehow heard about heaven and hell, and that was definitely what drew me in. I was terrified of the idea that people didn't get what they deserved, that bad things happened to good people, that when people died they were really gone forever. When I asked my mother about concern she explained that life isn't fair. But I knew that couldn't be true. Because if it was, if there was no supernatural protection against evil and death, then of course everyone would be frantically working to make it better all the time. I knew there were kind, intelligent people in the world, and they weren't doing this, so they must have a good reason, like that they didn't need to for reasons I didn't know about. I was very confused, and the idea that most people believed in heaven and hell, and it was "okay" that life wasn't fair and we were all going to die because the afterlife was fair and lasted forever, made a great deal of sense to my 4-year-old self. I was quite relieved.
But when I learned more about the Christian afterlife, and realized you either got profoundly inexpressibly screwed forever or bliss forever, and which one you got depended more on where you were born and how much you followed the rules than anything else, I realized that was no more fair. Maybe less so, since the result would last forever. And, I thought, if Christians really believed that, why didn't they go around trying to convert people 24/7? Were they psychopaths? They thought everyone's eternal soul might be condemned eternal torture and they didn't spend every waking moment eating, pooping, or prosthelytizing? Little-me tried to think about being tortured for an hour and not being almost done. And a day and a year and a hundred years and I realized it all didn't make sense.
So I modified my belief to fit my moral code, making my own personal version of the afterlife a new life where everyone got exactly what they deserved. Which helped me rest easy for a short while. But I noticed that other people didn't like my version of the afterlife as much. And they didn't seem that interested in how unfair the world and their vision of the afterworld were so lacking in justice. I know I was a naive little kid, but I felt very alone, like I was the only person really trying to make sense of things. But the truth, that we die, sometimes young and sometimes horribly and sometimes after being treated like shit for our whole lives, was too terrible and strange for little-me to believe in for a while.
I remember the first time I heard about cryonics, when I was 7. I was staying up late with my father watching some scientist talk about some new cryoprotectant. It took about 5 seconds to convince me that cryonics was a good idea. I started crying and my father couldn't understand why. I simply hadn't realized there might be another option besides dying within my lifetime. But even this possibility disrupted my fair-afterlife fantasy. It didn't seem to make sense to base all of my actions off of incredibly slim chance that everything would suddenly get fairer when someone died, especially if I was willing to abandon the belief when I learned I might not have to die. So I kept trying to find out something that didn't depend on a frail, unknowable hope.
I think the disparity between what people professed to believe was true and what they acted like was true initially pulled me away from rationalism. I felt like there had to be some big simple explanation that I had somehow missed but made it all make sense. When I realized this wasn't true, I became much more rigorous about examining my beliefs and the beliefs of others, to make sure everything I was learning wasn't logically insane. I started informally studying psychology to try to understand the why people don't all sign up for cryonics, and why Christians don't spend all their time converting non-believers.
There were a few notable "aha!" moments.
One was that same night, at age 7, asking my father whether he had signed me up for cryonics, and hearing him say no, because he thought death was beautiful and lent meaning to life. I asked him whether, if every other parent had signed up their children, he still wouldn't sign me and my little siblings up because death was "beautiful", and hearing his voice crack as he struggled to lie to me with a straight face was one of those.
Learning about phrenology and angelology was another, because it confirmed my suspicions that just because lots of people did lots of work for many years in a respected field didn't mean everything they were doing wasn't wholly useless. I realized I needed a tool to make sure everything I did wasn't useless. Rationality seemed to help with that.
Other moments included:
randomly picking up Peter Singer's Animal Liberation at age 12, and thus learning about utilitarianism.
realizing that I could win arguments even when I knew I was wrong and the other person was right (because I didn't want to lose my reputation as the local smart person), which meant I could probably win arguments against myself to protect myself from similar discomfort.
reading Watchmen and thinking about a scenario where (spoiler) the enemy turned out to at least maybe be right all along, and maybe (which contrasted, at least in my mind, with "The Ones Who Walk Away From Omelas" and the idea that utilitarianism was wrong in some ineffable way that could be proved through storytelling).
Since finding HPMOR and LessWrong, I've had many more, but I think the priming that came before was necessary, at least for me. A lot of the time, just hearing someone else say the ideas I've had all along, but felt weird/crazy/unwelcome for trying to articulate has been crucial.