Wow...I can't believe that would be in question. First of all...art is great for fine motor development. Also it is a great place to experiment and explore. I would start doing the research...because there is tons relating to artistic development for younger children. You are looking for research that is development with art education. Start with Lowenfeld. HE did a tremendous amount of reserch. Also there are lots of studies out there re: art and young children. Also, a person on our staff recently wrote a book.....I belive the title is "Young At Art" which discusses artistic development I think 18 months-age 6. Make sure you go in which hard data and even some charts and graphs might help. Most school boards are data driven. Something art folk have a hard time accepting...and you have to meet them on their playing field.