The academic interest in popular entertainment was long retarded by a class attitude that regarded it as a cultural phenomenon of inferior quality. Those who researched it were collectors and enthusiasts rather than professional scholars. The disdain of the Frankfurt School was also a factor. In the 1960s, with the rise of leisure studies and a Marxist-inflected interest in working-class culture, this began to change. The study of popular forms is now an accepted, even dominant part of the humanities curriculum, though still occasionally tinged with apology.