I've never met a good programmer who didn't know multiple languages so you may very well be correct. But I'm still interested in the correlation vs causation question.
Anybody know of research pointing either way or know a good programmer who only knows one language?
Maybe we won't count SQL, HTML, XML, etc. as languages. So someone who does web dev and only knows PHP would count as knowing only one language?
I do consider all of those languages. I've written a series of articles about various paradigms.
Now, it's quite possible to hack around in all of those and get a site working without really understanding why. Or it's quite possible to over-apply PHP and ignore all those other bits. Thus simply using these bits isn't enough to be a good programmer, but truly understanding all the bits probably is.
I'm surprised by how often you and I seem miles apart when we first comment on something but then when we peel back the layers, and maybe define some terms, we end up pretty close to each other.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.