What's the origin of "it's the same banana"?

Solution 1:

it's all the same banana

This appears to have originally been an idiom in Asian English with the meaning "It's all the same (thing)." See this 2002 bulletin-board discussion at "Myths About the English Language/Teaching English in Taiwan", forumosa.com which includes various conjectures:

From various participants in the discussion:

Besides, we must always remember that it's all the same banana.
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But, as Sally points out above, “It’s all the same banana.”
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(And if anyone can let me know what this supposedly common English idiom is supposed to mean, and who uses it, I’d be most grateful.)
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Seriously, do British speakers ever use/have they ever used “it’s all the same banana”? It came to me via a list of idioms for inclusion in materials, sent on very seriously by a well-known and well-respected professor of English on this fair island.
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As for the banana quote, it seems to mean simply “the same sort of thing”. I’m not sure who uses it and, thankfully, I’ve never heard an American utter that particular phrase.
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Back when bananas where few and far between, London society hostesses trying to get ahead would demonstrate their status by leaving a banana lying casually around the house. This led to something of a ‘fruit race’ with each hostess trying to outdo the other on the quantity of casually strewn bananas in their reception rooms.

Only the richest and best connected could keep up. But some blackguards (lit: someone who’ll stop at nothing to prolong unnaturally the life of their banana) found that just 2 or 3 bananas, strategically placed and moved at speed by servants, could give the impression of a whole bunch to visitors.

Hence the putdown (not to be used lightly): “It’s all the same banana.”
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But for the “banana” question, just refer them to this thread. I’ve been doing some research on the subject, and I believe that the phrase “all the same banana” derives from the politically correct prostitutes’ movement of the early 1990s.

I found the following in Google Books. These examples also have an Philippines/Asian connection)

"...You mean I traveled to another dimension?" Solenn shrugged. "Plane, world, dimension, realm. Doesn't matter what you call it. It's all the same banana to me." Karren Seña; Lost Chronicles of Eden: Champions (2014)

(I believe Karren Seña was educated in the Philippines)

When asked, for instance, to link their founder with other historical personalities, one of my informants responded: "They are all one." A decade and a half ago, in a different place, a similar query by an earlier researcher solicited a similar response: "It's all the same banana" Sturtevant: 1976). Asian Studies, vols.17-20

(This is the relevant snippet from the Sturtevant work, Popular Uprisings in the Philippines, 1840-1940, p.276. Unfortunately the snippet has no additional context.)

it's the same banana

Aquino has changed the administration, but it's the same banana—they're still politicians. John Waterbury; North for the Trade (1972)

A lawyers' group, Mabini (Movement of Attorneys for Brotherhood, Integrity and Nationalism, Inc.), known for handling political cases free, points out: "It's the same banana—only worse. Reason to Hope (1983) (Snippet View)

People who don’t know the good and bad side of SEO thinks that it’s all the same banana and they could simply hire the cheapest provider with the most promises. While this is a sad truth that’s happening today, we can do something about it. Sean Si; aragil.com