I was doing some research, and came across this paper written about Rastas in science ficiton. It appears to be a student paper for a Dutch university course on cultural identity. I would like to share with you one particularly cogent observation about The Phantom Menace:
… many of the alien characters seem to be based on racial stereotypes. Most of the time however, it is hard to ascribe a character to one racial stereotype in particular. Because they are not humans but alien life forms, their features leave room for different interpretations, as do their accents and overall behavior. Some of them seem to be based on combinations of several stereotypes.
I like to think that Lucas just put a bunch of cliches and stereotypes in a bag and got a trilogy out of it.