Well, that's certainly the case for non-fiction. In a non-fiction book, a paragraph is one, coherent, logical unit of argument. A chapter is like an essay in its own right, with its own thesis statement and conclusions to cover one aspect of your subject. But when I turn my hand to fiction, my goal as a writer is slightly different. I am not trying to analyze my subject matter in a logical way, I am enticing the readers to keep reading, and to enter into the world of my story.
This means I want my scenes and chapters to blend seamlessly together, so that readers won't meet with anything to throw them out of the story until they reach the last page. In this context, any break I make to the text is rather arbitrary. There's only one purpose for a chapter break: to give readers a moment to stop, to reflect, and to revive before they move onto the next bit. It puts me in mind of advertising campaign we have here in Australia, aimed at people driving long distance -- the slogan is, "Stop, revive, survive."
While we're on the subject, there's one more, slightly off the wall idea I have about chapters. I sometimes think it would be a good idea to number chapters in reverse; e.g. the last chapter in the book would be 1, and the first would be 27 (or whatever). It's the way they do best-seller charts and top ten lists, and I'd be doing it for much the same reason: to create that same sense of rising anticipation. The reverse numbering would better serve what I'm trying to do as a writer. But, of course, if I actually did it people would react as though I'd slapped their grandmother's or something -- people get their knickers in a knot over the silliest little things.