What is the definition of a real lisp? AFAIK lisp is just a family of computer languages. Elisp certainly isn't the most powerful or full featured but it still seems to have most of the characteristics.
(Concerning the comments) Amazing how subjective people can be about this stuff. I thought the response from Stuart Halloway was well considered and fact based.
The problem is obtaining this evidence is really hard. So many considerations are involved during the coding of a non-trivial system. It's hard to isolate all factors involved. I remember code complete presenting some evidence that 100-200 line functions are the best size but how true is that really? What consideration does language have on that? Most people these days would see that functions that size as way too long.