That historical example did a lot to persuade me. Do you have any others similar to it?
I used to share your position, but moved away from it. The main reason I did is studies such as the ones mentioned in this article:
http://online.wsj.com/articles/SB10001424052702304854804579234030532617704.
How do you explain such results?
The main reason I did is studies such as the ones mentioned in this article:
http://online.wsj.com/articles/SB10001424052702304854804579234030532617704
The article is behind a login wall. It would help linking directly to studies instead of a badly accessible article about them.
To guess at the point, we find that obesity within the US has a strong genetic component. On the other hand we find that obesity strongly changes over the time span of decades. The fact that something seems to be genetic within one population seems no good evidence that there are no societal factors involved.
What is something you used to believe, preferably something concrete with direct or implied predictions, that you now know was dead wrong. Was your belief rational given what you knew and could know back then, or was it irrational, and why?
Edit: I feel like some of these are getting a bit glib and political. Please try to explain what false assumptions or biases were underlying your beliefs - be introspective - this is LW after all.