豪華客船が沈む時
様々な民族の人が乗った豪華客船が沈没しそうになる。
それぞれの乗客を海に飛び込ませるには、どのように声をかければいいか？
イギリス人には、「こういうときにこそ紳士は海に飛び込むものです」と伝える。
ドイツ人には、｢規則ですので飛び込んでください」と伝える。
アメリカ人には、「今飛び込めば貴方はヒーローになれるでしょう」と伝える。
日本人には、「みなさん飛び込んでますよ」と伝える。

When a passenger liner sinks.
The liner, with representatives of different nations, will soon sink.
How to convince different passengers to jump into the sea?
The Englishman should be told: "It is at such a time that a gentleman should jump into the sea."
The German should be told: "This is the rule, so please jump."
An American should be told, "If you jump now, you might be hailed a hero."
The Japanese should be told: "Your comrades are already jumping."

Grammar comment
Let's analyze one of the meanings of the grammar ものです (mono desu) used in a joke in with the Englishman: 「こういうときにこそ紳士は海に飛び込むものです」(ki ni koso shinshi wa umi ni tobikomu mono desu) - " It is at such a time that a gentleman should jump into the sea.”
This ending expresses a social (moral) obligation, expectation, tradition. It is not used if you are referring to personal circumstances.
- 人はお互いに、助け合って生きるものだ。 (Hito wa otagai ni, tasuke atte ikiru mono da) - People should live by helping each other.
— 日本業界では、自己紹介をする時、名刺を交換するものです。 (Nihon gyo:kai dewa, jikosyo:kai wo suru toki, meishi wo ko:kan suru mono desu) - In Japanese business circles, when you represent yourself, you should exchange business cards.
As you can see from the above sentences, mono desu is usually preceded by a simple verb. The word “should” is often used as a translation of this grammar, but this imperative is not due to personal opinion, but to the established order of things. Note that mono desu is always placed at the end of a sentence.

Linguocultural commentary
This anecdote makes fun of the desire of the Japanese to be like everyone else. This is clearly not a society where individuality is welcomed. A well-known Japanese proverb says: 「出る杭は打たれる」 (Deru kui ha utareru) - "The nail that sticks out is hammered." Sometimes it really comes to the ridiculous: half-breed children with lighter hair color in some Japanese schools are forced to dye their hair in traditional black in order to meet generally accepted standards.

Do you agree with the proverb about the nail? Share your thoughts in the comment!