American cartoons were originally created and broadcasted for the entertainment of children. And they did just that. Cartoonists used elements like giving human characteristics to animals and other inanimate objects. Storylines were funny, and funny in the most basic ways: ways that small children could understand. (Walt Disney is the prime example)
Even when it's not directed toward little kids, cartoons are still supposed to be funny, or have humorous points: i.e.: The Simpsons, King of the Hill, and most importantly: Beavis & Butt Head.
Japenese Anime, however, is completely different. Whether directed toward children or adults (usually children), they are animated versions of mixed concepts that Americans have been doing the live-action versions of for a long time: Either soap-operas or sci-fi, mostly sci-fi. The only two examples that pop into my head right now are Dragon Ball Z and Gundam Wing. Anyway, they would be just as good if not better in they were made into live-action.
As for realisticy: Anime sucks. In old American cartoons, and even the newer ones, the characters would act and pose as people would. When they talked, they would move. -Not actually move about the room, but they would turn their heads or "talk with their hands", or they would be moving in some other small way. Same thing when they walked: (If you want and example of this, watch any episode of Scooby Doo) the characters would move their heads, swing their arms, and act as people do when they're walking.
And for the Anime side: When anime characters walk and talk, they keep their poses. Their hands stay in the same place, and their heads never move and inch from side to side. Their facial expressions are also noexistant most of the time. (the little stress mark on the forehead doesn't really count as a facial expression. It only serves to inform the viewer that the character is stressed or mad or something)
My oppinion: We should just go on ahead and turn every Anime cartoon into either a soap-opera or a sci-fi series.
Yet another topic: Cartoon Netword used to show all of the good old American cartoons. That has been greatly reduced, now since Anime is on more than half the time.
Fortunately, somebody was smart enough to dedicate a whole channel (Boomerang, or just Bam) to the old American cartoons.
Why don't they just scrap Cartoon Network, play the American cartoons on Boomerang, and create a whole new channel just for anime?