From Lauri Karttunen (via Arnold Zwicky):
I have come to realize that there are a lot of examples on the web of the type "not want to not X" that seem to say the opposite of what they mean. Here are a few:
She failed to give the patient CPR and turned an ambulance away in the mistaken belief that the elderly woman’s had said she did not want not to be resuscitated. (Cambridge, UK, newspaper article)
If a guest does not want not to be disturbed they need only to place the 'Do Not Disturb" sign on the door and their wishes will be respected. (Florida motel)
In the first case, the mistaken belief was that the elderly woman did not want to be resuscitated. In the second case it should say "If a guest does not want to be disturbed …"
I first thought that these were isolated errors but there are so many of them that they cannot not all be errors. You find this phenomenon with "wish," "desire," and even "expect:"
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If the girl remained unkissed, she could not expect not to marry the following year.
Do you know if something has been written about this phenomenon? It doesn't look like negative concord.
As Arnold observed in response, this appears to be a new type of misnegation, of the overnegation variety, not previously catalogued. And Larry Horn noted
I can only add that one feature that often leads to (or at least accompanies) hypernegation, including the cases illustrating what I call "Triplex negatio confundit" and "Quadruplex negatio far'blondiat" (in my old 1991 CLS paper on "logical" double negation), is the lexical incorporation of (at least) one of the extra negatives. That property is present in some of the examples below ("She failed to give the patient CPR and turned an ambulance away in the mistaken belief that…"; "Nor will we waste your time…", "If the girl remained unkissed,…", and arguably also "they need only…"), so that may be a factor even when the incorporated negatives are in a different clause. In the third example, perhaps the "If not p then not q" form may have thrown a monkey wrench into the mix; I wonder if the hypernegation would have arisen had the consequent been simply "please leave immediately". In the remaining example, there's a "nor" anticipated in the later clause. I'm not claiming there's an inevitable relation between the processing of some negations (which is known to put a strain on both production and comprehension, back to work by P. C. Wason, Herb Clark, and others) and the difficulty of keeping track of others, but there does seem to be a correlation.
Update — There has been some discussion in the comments about whether these examples are instances of editing errors, perhaps facilitated by interaction with word processing programs. FWIW, we can certainly find cases of this kind that were written well before the era of computerized word processing, such as this passage from the address of Walker D. Hines to the National Lumber Manufacturers Association, published in Lumber World Review, April 23, 1919:
Broadly speaking, the policy of the Railroad Administration is that the advisors on each railroad will continue to make their purchases just as they did before the war and on the same general basis with, however, some limitations to prevent the exercise of undue pressure for a considerably lower price. The Railroad Administration could get no ultimate advantage by prusing such a short-sighted policy. It has no such desire nor has it a desire to bring about prices for itself which are below the prices of of other purchases of commodities in substantial volume. It does not want not to be the beneficiary of special treartment which will result in putting a burden on the rest of the public.