Contestant Number One in the finals of the New York Japanese Consulate's annual speech contest was a Hispanic man in his early twenties who talked about playing baseball for a Tokyo high school. In impressively accented Japanese he bragged about fitting in so well that his teammates called him Taro, a common boy's name. He compared himself to Tom Selleck's character in "Mr. Baseball," a movie about an American who plays for a Japanese team.

Contestant Number Two was a short, blonde woman who wore a navy blue blazer and discussed her study of flower arranging and tea ceremony. Her accent needed work, as did her use of polite forms.

Contestant Number Three began by asking the standing-room-only audience, "Nihon-jin no cho to America-jin no cho to de wa, nani ka, chigai ga arimasu ka?" Is there any difference between Japanese people's intestines and American people's intestines?

Big laugh from the crowd. And that would cost me.

I was Contestant Number Three.

Like many Americans, I grew up believing that, aside from surface characteristics and susceptibility to certain diseases, members of the human race are essentially the same. Perhaps this had something to do with the many hours I spent watching Sesame Street and listening to Free To Be You and Me.

Ms. Yamada was raised with a different message.

Ms. Yamada was my teacher at the college on the outskirts of Tokyo where, in 1988, I studied Japanese for two semesters. Ms. Yamada had puffy cheeks and a high-pitched voice, and every day she brought our class a newspaper article so we could practice reading kanji characters. One day she brought an article about the Beef and Orange Trade Problem.

Everyone who lived in Japan in 1988 knew about the Beef and Orange Trade Problem. The problem, according to the United States, was that Japan was charging high tariffs on American meat and fruit. The problem, according to Japan, was that the United States thought that this was a problem.

Ms. Yamada led us through a character-by-character dissection of the story, which summarized the positions of the respective governments. There wasn't much new information, until we got to a quote near the end. It was attributed to Tsutomu Hata, Japan's then-minister of agriculture.

"To the Japanese intestinal system," Hata said, "it will mean a very big change to eat more beef." Then he explained why: "This is because Japanese intestines are longer than those of Americans."

A German girl named Astrid raised her hand.

"Kore?" she said, pointing to her abdomen.

Ms. Yamada nodded.

"Yours are longer?"

From the expression on Ms. Yamada's face, Astrid might as well have asked if fish really swam in the sea.

Ms. Yamada said, "Doesn't everyone know that?"

I had already been studying in Japan for several months, which was long enough to encounter other peculiar notions about the physical uniqueness of the Japanese people. For instance, I had read a book claiming that the Japanese brain was structured to hear the buzzing of certain insects (especially cicadas) as a kind of music. Once, when I had a cold and was sniffling on a train platform, a middle-aged woman walked up to me and said, "How could your nose be that big and still get stuffed up?" Even now, if you ask a Japanese woman how long a typical pregnancy lasts, she'll probably say ten months.

It might have been easier to shrug these off if Japan hadn't been doing so well economically. The country's rising power seemed to embolden people, and I got the feeling that the uniqueness beliefs were about not only being different, but somehow better. Besides, I don't remember if Free to Be You and Me came right out and said that we're all the same on the level of our internal organs, but to my mind it was certainly implied. So, as much to defend a view of mankind as to satisfy my curiosity, I took a stand, and set out to prove Ms. Yamada wrong.

The first thing I did was ask Japanese students on campus if they had heard about differences between Japanese and American intestines. I jotted down the responses in a notebook:

"Yes. Japanese ones are longer."

"Japanese are much longer."

"Never heard that."

"Japanese intestines are exactly 1.5 times longer."

"Who told you that?"

The initial answers were statistically similar to those I received from surveying a total of 120 students. Overall, 65 percent believed that Japanese intestines were longer. I heard the suspiciously precise "1.5" figure four times.

When respondents told me that their intestines were longer, I asked if they could explain why. Answers to this question were remarkably consistent. As a male on the tennis team explained, "We Japanese were traditionally an agricultural people. Our ancestors didn't eat much meat, so we evolved a longer intestine to digest the vegetables."

I asked him, "You mean, like how cows need four stomachs to digest all that roughage?"

"Exactly," he said.

That explanation seemed reasonable at first, but I detected an air of superiority in it. It positioned Americans as lion-like carnivores, aggressive when they're hungry but lazy most of the time. The Japanese came off as diligent grazers, always chewing, always working.

And the more I thought about it, the more I saw holes. First of all, the identity of modern Japanese people's ancestors is one of the great mysteries of Japanese archaeology. (Much evidence points to the culturally unwelcome conclusion that they came from the Korean peninsula.) Second, although today's Americans eat a lot of meat, our ancestors (is it even possible to generalize about "our" ancestors?) ate less. Then there was the idea that evolutionary changes in intestinal lengths happened relatively quickly. One girl in my survey predicted that, during a planned year-abroad study program in the United States, her intestines would surely shrink.

Luckily I got involved in other things, and for a while I didn't think about Japanese intestines at all.

After studying in Japan I got a job in New York with a company that produced TV programs — news, documentaries, game shows — for networks in Japan. One night I was having a beer with a cameraman named Naoki when the intestine question suddenly popped into my mind. I asked him about it.

"I heard that," Naoki told me. "And something else."

Naoki said that a friend once told him — I'll try to put this more delicately than Naoki did — that because of their long intestines, the Japanese were the world's most prodigious producers of solid waste. In fact, the reason Japan lost World War II, according to Naoki's friend's theory, was that American soldiers were able root out hidden Japanese troops simply by looking for extra-tall piles of human dung. To his credit, Naoki was laughing as he told me this last part, and stressed that he wasn't one-hundred-percent sure it was true.

Not too long after that, a prime-time Japanese variety show hired me to film an aging comedian on his Manhattan vacation, which happened to include a colonoscopy performed by Hiromi Shinya, a Japanese-born gastroenterologist at Mount Sinai Hospital. While the comedian was resting (a video clip of his colon — along with a clean diagnosis — was later broadcast on Japanese TV), I asked Dr. Shinya about the length of Japanese intestines.

Dr. Shinya said he didn't feel comfortable speaking to an American reporter, and when I explained that I wasn't a reporter, he said it didn't matter. Nevertheless, he recommend that I purchase his book, Icho wa Kataru (The Digestive Tract Speaks), at the Japanese bookstore in Rockefeller Center.

Part memoir, part guide to intestinal self-help, the book included Dr. Shinya's reflections on his early days as a physician in the United States. I was intrigued by this passage:

"…when I looked at the intestines of Americans whose diet was primarily meat-based, I could hardly contain my astonishment. Their intestines were stiff and short… On the other hand, the intestines of people — even some Westerners — who subsisted entirely or primarily on a diet of grains, beans, vegetables and fruits, tended to be very smooth and relatively long. The latter type is common among Japanese people, and leads to a much better intestinal condition." ¹

Five years later I was working for a computer consulting firm when a friend introduced me to Internet search engines. The first thing I typed into Yahoo was "Japanese AND intestines AND longer."

On the third page of results, in the archives of the Historical Medical Library at the College of Physicians of Philadelphia, I found an abstract of an academic paper titled "The Length of the Intestine in Japanese." I called the school and paid a librarian $10 to mail me a copy.

The paper was an English translation of a document penned by Henrich Botha Scheube, a German physician, likely around 1880. (The manuscript was undated, but the librarian told me she had found it in a box with other papers about Japanese physiology that had all been written between 1876 and 1889.) Dr. Scheube began by citing his hypothesis that Japanese intestines might be longer:

In my [previous paper,] 'Remarks on the Japanese Diet,' I said that very probably rice is better used up in the intestine of the Japanese than in that of the European, and I expressed a surmise that the Japanese intestine must be the longer of the two.

Consulting a German anatomy textbook², Dr. Scheube learned that intestines in Europeans were typically between 800 and 900 centimeters long. To test his "surmise," he gathered measurements on the intestines of 26 Japanese corpses aged between 17 and 60 from a Japanese hospital. Of the combined data set, he wrote, "The 26 cases give a length of intestine of 953.7 cm. The maximum was 1203, the minimum 667; only 3 times the intestine was below 800…Accordingly, even the absolute length of the intestine is greater in the Japanese than in the European."

The difference was even more pronounced when Dr. Scheube accounted for the fact that Europeans were, on average, 11 centimeters taller than Japanese people. Relative to body length, he found that Japanese intestines were 20 percent longer. He cautioned, however, that 26 intestines were not a lot to go on.

"Whether further measurements will confirm these conclusions," he wrote, "remains to be seen."

Ten years passed. I had moved to San Francisco, and was dating a psychologist. One day she told me that a Japanese doctor was visiting her hospital.

"Could you introduce me?"

"Why?" she asked.

"Just something I want to talk to him about."

His name was Fumio Shaku, and he was a psychiatrist. I invited him out for Korean barbecue, but he said he had never heard about the intestine difference.

A few days later, though, he called me on the phone sounding excited.

"You were right!" he said. After our dinner, he told me, he had emailed a gastroenterologist he knew in Tokyo. "My friend says Japanese intestines are definitely longer. Sometimes, when he's performing colonoscopies, he actually runs out of cable. He says he doubts such a thing ever happens in the United States."

I discounted this last testimony as ludicrous until a couple of years later, when my gallbladder became infected and had to be removed. After my operation, I asked my doctor, an American colorectal surgeon named Jeff Sternberg, the question I had now been asking for nearly 20 years. He surprised me in two ways: (1) by not dismissing the notion as ridiculous, and (2) by using the word "colonoscope" as a verb.

"I don't have data or anything," he said. "But it's kind of known in the field that when you colonoscope Asian woman, especially young Asian women, their colons are like, really freakin' long."
I asked Dr. Sternberg if there he knew of a text book that provided lengths from American cadavers, but he assured me that such measurements would have little meaning.

"Intestines are funny," he said. "They're always contracting and expanding."

The Consulate held the speech contest in the auditorium of the Japan Society, not far from the United Nations. Each contestant spoke for ten minutes in Japanese, and I used my time to lead the audience through my quest for the truth. I had to admit that I still wasn't sure what the truth was, and that, as strange as it sounded, Japanese intestines might indeed be longer.

I wrapped up my talk by listing some of the other beliefs I had heard, including the one about insect noise sounding like music and how it took ten months to have a baby. The last one, I said, might be explained by Japan's traditional use of the Chinese lunar calendar: Japanese and U.S. doctors agree that the human gestation period is 280 days, which is ten 28-day months.

Or — and this was my punch line — maybe Japanese babies just needed an extra month to grow their extra-long intestines.

Huge laugh.

The head judge, a short, bearded Japanese academic, announced the results. The baseball player came in third, and I was runner-up. The judge said "Mr. Raskin's speech was very funny." At first I thought he was praising me. But then I remembered noticing him in the audience while I had been giving my speech: he was the only one not laughing.

The blonde woman with the bad accent won first prize — two round-trip tickets to Tokyo. In her follow-up Q&A she was asked which Japanese season she liked best. "Spring," she said, "because the cherry blossoms are in bloom." The head judge cited her answer as proof that she truly understood the uniqueness of the Japanese people.

¹ From Icho Wa Kataru. My translation.
² Scheube called the textbook “Hoffman’s Manual of the Anatomy of Man.”