In a couple of hours we'll be chewing over the highlights of the third presidential debate, but you'll still want to check out Ben Zimmer's nice column on the blended idiom Obama produced in debate no. 2: "green behind the ears."
Surely this is just a combination of green (as in naïve) and "wet behind the ears" (as in newborn and not yet dry in all the hollows). What's surprising is its age: Zimmer finds "green behind the ears" in print as early as 1924. And according to a couple of commenters, the variant exists in German too.
All these damp ears reminded me of "wash behind your ears," a familiar admonition from books if not from my own childhood. How did that area come to be singled out for special scrubbing?
Google Books turns up some references to washing behind the ears for therapeutic purposes -- headache cures and the like -- in the early 19th century. But the earliest reference to childish ablutions comes from the British humor magazine Puppet Show, in 1849, in a list of (supposed) etchings done by Queen Victoria and Prince Albert (who really did do etchings):
-- Portrait of the Princess Royal. -- Portrait of the Princess Royal with her hair in papers. -- Portrait of the Princess Royal before having her face washed. -- Portrait of the Princess Royal refusing to allow the nurserymaid to wash behind her ears. --Portrait of the Prince of Wales being sent into the corner.
Then comes "Portrait of the Prince of Wales being sent into a corner," and so on.
This focus on ear cleanliness continues for more than a century. A few samples:
"'Bathe other people's children; but don't wash behind their ears.' -- That is to
say: Do not be servile in obsequiousness to others." (Little Dictionary of Creole Proverbs, 1885)
"I'll wash behind my ears too, without being told." (Lucy Maud Montgomery, "Anne of Avonlea," 1909)
"[W]ith the expression of a small boy who has been publicly exhorted to wash behind the ears, [he] said: "Some days he's here, some not." (Dorothy Sayers, "Busman's Honeymoon," 1937)
"[S]he would never really forgive him for being able to button his own buttons and wash behind his ears." (William Faulkner, "Intruder in the Dust," 1948)
Why the century-long ear thing? It must have been the intersection of the Industrial Revolution's built-up grime and the dawn of indoor plumbing, with its rising standards of cleanliness, that triggered it. A century or so later, getting really clean was no longer hard work, and we've gradually given up treating retroaural cleanliness as the index of a young person's hygienic competence.