I’m sure that I have a memory of this expression being used when I was a student and working on a summer job on the building of the Spaghetti Junction motorway interchange in Birmingham, England. That would have been in the summer of 1969. At this point I need to add the usual warning about the fallibility of memory. Just because I have a clear memory of hearing the phrase in 1969, that doesn’t prove that I did.
However, there is documentary evidence of the phrase beginning to be used in England in the late 1960s. The first example I can find of it in print is in Pigeon Racing News and Gazette – Volume 25, 1969:
Just got me knickers in a twist after the New Year celebrations.
Earlier citations may well turn up, although I doubt that the phrase pre-dates the 1960s.
What may well have preceded ‘knickers in a twist’ is the rather more linguistically satisfying ‘knickers in a knot’. That is the preferred version in Australia. It certainly has the lively tone that many Australian phrases enjoy. It was in use in print there prior to any citations of ‘knickers in a twist’ elsewhere in the world.
The first example that I can find of that form of the phrase is from another Commonwealth country – South Africa. That’s in The Train from Katanga, a 1965 novel by the Anglo-South African writer Wilbur Smith:
“Okay, okay, don’t get your knickers in a knot, bucko.”
Back in Australia, in September 1972 an article in the Meanwhile In The World journal included an illustrative picture with this caption:
Kyomi Kato and Gordon Bertie get their knickers in a knot during a very freestyle wrestling match.
So, we don’t know who coined the expression, but ‘don’t get your knickers in a twist’ probably originated in the UK as a variant of the imported ‘don’t get your knickers in a knot’.
Compared to the many other proverbs which advise you to not to do something, for instance, don’t let the grass grow under your feet and don’t look a gift horse in the mouth, don’t get your knickers in a twist seems like especially useful advice.