The benefits of learning languages that you won't use
I have read numerous time that learning a language such as Haskell, Lisp or Smalltalk will somehow make you a better programmer while you program in other languages.

Is there more than just anecdotal evidence for that claim? 
Or is it just the way people rationalize having spend a lot of time learning a programming language that they will never use?
The benefits of learning languages that you won't use
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I have read numerous time that learning a language such as Haskell, Lisp or Smalltalk will somehow make you a better programmer while you program in other languages.

Is there more than just anecdotal evidence for that claim? 
Or is it just the way people rationalize having spend a lot of time learning a programming language that they will never use?