It's nice to find many other liberal arts educated people on here interested in the industry. I think there really is value in having diverse interests working on any project, whether that's game development or otherwise. Being interested in things like classical lit, myth and psychology I see the intersections with these fields of interest in almost every successful game out there.
Case and point: there was a recent article on myth theory and game design on gamasutra. I don't think understanding how mythic structure works is entirely necessary for a designer, but if you read Joseph Campbell or Northrop Frye you are going to have a better grasp of what the characters' actions mean to the player, how both stories and gameplay still work with the same archetypal narratives as other media and literature.