Right. My anecdote isn't directly contrary evidence, but it is a contrary hint. If reading fiction were an excellent way to build vocabulary, I'd expect to see acquaintances who avidly read fiction to have larger vocabularies than acquaintances who don't read fiction. This is not what I see.
It might be that my acquaintance sample is weird. It might be that avid fiction readers fluidly express themselves with simple words where the less well-read resort to obscure vocabulary. But (over)generalizing from my personal experience, I (somewhat) suspect that people's vocabulary has less to do with the fiction they read than is usually assumed.
I had a different model in mind. I think there's a satiation point on exposure. If you were raised by consummately literate native English speakers, then perhaps you acquired a choate vocabulary simply by immersion in that environment. Additional reading of fiction therefore, will offer you only the meagerest of marginal improvements. Many people weren't raised by excellent speakers of English though, and these individuals are the ones more likely to gain from increased exposure.
Would you make the same statement about the relationship between reading novels in Spanish or German and improving vocabulary in those languages?
Although my 8-year-old son likes his teacher, he is frequently bored at school. He attends a high quality suburban public school in the United States. He has a lot of traits in common with LessWrong readers, and we would like advice for what he can do to counter his boredom. Many of you must have found grade school more or less tedious. What were your coping strategies?