Simplicity is overrated, and a spate of research on "cognitive fluency" and "disfluency" is just starting to put it in perspective. One study that should jar some "plain language" proponents, for example, found that making high-school texts harder to read improved retention. (See http://tinyurl.com/3aouvja) Balancing simplicity and complexity is no simple matter, but science is finally addressing it.

I have a blog on writing—legal writing, actually—and it's the only place I've seen the cognitive-fluency research seriously applied to persuasive writing. Most often, the research is misinterpreted to favor the old plain-language pablum of one-sided simplification. The most persuasive writing doesn't clock in with a low Gunning fog index; consider Darwin's writing style, which is anything but simple—rather, simply excellent. (See http://tinyurl.com/48dxal4)

My blog, "Disputed Issues: Controversies in Legal Writing," is at the link. The advantages of disfluency are discussed at http://tinyurl.com/3e9fqcs; integration of cognitive-fluency research with working-memory research, at http://tinyurl.com/3qz3gxd

[The final link was bad: corrected 7:54 p.m., 8/30.]