The score by itself is nothing. We meant that feature analysis, key signature etc. are not consciously inferred but that our brain automatically detects the acoustic differences between musical scores which are written with those characteristics. Sorry for the sloppy formulation. Yes, scientists are in most cases conservative and rarely musically sophisticated. Our distinction pop versus classic is not real, we discriminated between subjects which indicated their preference for pop or classic in a questionnaire only.
Pop can be musically more complex of course.