You'd be surprised how much a seemingly unrelated field of study can help with anatomy, character and world building, depending on that individuals method of study. For me, Zoology could be beneficial for drawing animals, not only learning their anatomy through interacting and study but also learning their mannerisms and deeper biological stuff. I used to want to be a doctor, not only because it was something of interest but because I knew it would be spectacular help as far as human anatomy, illness and injury.
I can see how fields like psychology, archeology, astronomy, geology, etc can help with art and story/character/world building.
Sorry, I like babbling about stuff like this.