And given the problem of being understood in noisy places, what are people doing with "No?"

2. What I notice is that people on the phone tend to use very informal versions of the affirmative, "Uh-huh," "Yeaah," "M-hm." I don't think I say, "Yes" very often because it seems weird and stilted when I deliberately do it navigating one of those speech-recognizing voice-mail systems which (I would guess) relies on that 's' to distinguish it from a "no."

So my theory is people are used to using language that seems too informal for a radio interview and they over-"correct."

3. Alternate theory, maybe "yes" seems too short and indistinct when you imagine your words going out over the radio. Maybe "That is correct" is the functional equivalent of saying "Yankee Echo Sierra."

I'll go read Goffman on the subject. I'm a great admirer of his Presentation of Self in Everyday Life and my eldest son credits the availability of that book in our home library for his success in later life in the world of finance.

If I remember correctly, in Nepali you can express affirmation by saying /ã/, while negation is expressed by /ahã/ (which is extremely confusing as it sounds so much like "uh huh"). And these are what I think you mean by "non-verbal", as in not the standard, formal way to express these concepts.

The confusion is further complicated by the fact that the Nepali body language for "yes" involves a sideways figure 8 head wobble that looks more like "I'm not sure… maybe, but probably not" rather than "yes" to Westerners.

Pray expand! I'm dimly remembering Goffman's argument in "Response Cries" that these are not as unconscious or automatic as we make them out to be, but I've never heard of any real investigation into them.

@GKP: Oh yeah, there was a question. I do say "That is correct," "That's right," etc., especially to my students, just to be a little silly. I also use it occasionally to a friend, who picked up expression of that type from a friend of his, who picked them up while working with security guards who used (yes) radios a lot; all these people also say things such as "Copy."

Next: "You are correct, sir" from Johnny Carson's time on The Tonight Show?

The maximum winning for Lascia o raddoppia was ₤ 5,120,000, which was about $8,200 or 57,000 Danish kroner in the late fifties.

As an aside and one of those personal comments that provides the flesh (not the bones) of Language Log: Denmark had this quiz as well, but we were poor, and the maximum amount was puny compared to $64,000 – a mere Danish kroner 10,000. This was about 2.5% of the American sum! But this was poor, war-stricken Europe.

Swedes like to think of Swedish as a sort of secret code that no foreigner would ever bother learning, except maybe in an emigrant family. It took several months for my colleagues there (back in the 60s) to come to grips with the fact that I, a self-professed American, could understand everything they were saying around the coffee-break table.

Another linguistic give-away is what you say reflexively when you accidentally drop something.

This may be going far off topic, but the first Italian TV quiz show was Lascia o raddoppia, which ran from 1955 to 1959. Wikipedia reports it was the Italian version of the American show The $64,000 Question, coming to Italy via the French version Quitte ou double?

The American connection is reinforced by the fact that the host of that quiz show was Mike Bongiorno: an iconic TV personality for the following fifty years, the subject of another famous satirical piece by Umberto Eco (Fenomenologia di Mike Bongiorno), and an Italian-American.

I'm several decades too young to have seen that show, but it's highly likely that Bongiorno would greet a correct answer with "Esatto!" I am pretty sure that is considered one of his stereotypical utterances, jointly with "Allegria!"

Hence, I suspect Eco was serious in attributing the usage of "esatto" to TV quiz shows, probably thinking implicitly of Mike Bongiorno in particular—I feel it's still difficult to think about Italian quiz shows without thinking of him in particular, and I dare say it was impossible in 1990.

Whether the ultimate source is in fact an American "That's correct”, and whether a parallel development might have occurred in English, I cannot say.

*) until they tagged his afterthought concerning shaving on to it.