Hmmm - before writing a lick of perl, I considered myself a very experienced C/C++ programmer, and a beginner Java programmer. (Of course, you'll have to take my word on those.) Now I consider myself an experienced perl programmer (although you can form your own opinion on that from my track record). I do believe that my background in C, C++, and, especially shell scripting, all contributed very highly to learning perl quickly and becoming useful in it.

I do believe that I am one of the more effective perl programmers in our entire work group, and that I got that way partly from my C/C++ experience. That is, I learned to program, and then I learned some languages afterwards.

I suppose the key to me is someone who likes to learn idiomatically. Who likes to write C in C, Java in Java, C++ in C++, shell in shell, Fortran absolutely nowhere, and will then likely want to write Perl in Perl. I suppose the tough part of this is figuring out that the candidate is such a person - asking this question point blank is useless as most people will understand what the desired answer is and give it, even if they don't really understand the question. Figuring out a behavioural question for this is going to be interesting.