TV tropes takes a look at the tropes deployed (and subverted) in The Cabinet of Dr. Caligari. But… “The film was made to metaphorically express the dangers of hospitals in World War I when “malingering” soldiers were confined in hospitals under their manipulative doctors.” Really now?
Here’s some more interesting notes on The Cabinet of Dr. Caligari, from www.filmmonthly.com. Jon Sebastien is maybe a little too harsh on American filmmakers of 1920 (no deeper than a puddle?), but he more distinctly draws the direct line to from Caligari to Tim Burton, specifically Edward Scissorhands.
I came across this interesting piece on The Cabinet of Dr. Caligari, titled “Expression and Character in the Movements of Cesare.” If you agree with Nancy Thuleen’s basic thesis, you have to rethink the level of sophistication inherent in this film. To denote character by differing styles of movement is a big leap for 1920, but I see her point.