In USA and UK we take the "thumbs up" sign to be an indication of approval. It is used in many different scenarios including the "thumbs up" made famous by the Stumbleupon social network site.
The thumbs up sign was originally used by the ancient Romans to decide the fate of Christians in the arena. The thumbs up (pollice verso) sign meant "kill him" and the thumbs down, or hidden (pollice compresso) sign meant "spare him". In the film "Spartacus" the directors actually got this the wrong way round.
In most of the world it's quite acceptable to offer the thumbs up to people but if you are traveling in Afghanistan, Iran, Nigeria, or parts of Italy and Greece, take care. In these countries it is considered extremely rude and insulting. In Sardinia it is seen as particularly offensive and a hitch hiker thumbing a lift is more likely to be run down, than offered a ride.
Roughly speaking, in these countries, this hand signal is the equivalent to the "middle finger" salute which is common in USA and UK.
The term "thumbs up" is now used in English speech. For example, "The director gave me the thumbs up." In formal circumstances that phrase is acceptable where actually giving the thumbs up sign might not be.
So, it pays to research the customs of any country you might be visiting before you use the "thumbs up" or any other type of hand signal. It just keep you out of trouble, or at least improve your chances of thumbing a lift in Sardinia.
译文:
让地球上一半人感到恶心的手势
在美国和英国，竖起大拇指通常意味着赞成或通过，而这个手势还可以在其他不同的场景下使用，包括曾经因“竖起大拇指”出名的一些使用
Stumbleupon 这个浏览器插件的网站。
这个手势最早起源于古罗马时期，用来在竞技场上决定一个基督教徒的命运。大拇指朝上表示“杀了他”，而朝下则表示“饶恕他”的意思。在电影“斯巴达克斯”中，导演事实上弄错了这个手势的意思。
在世界上大部分地区，你竖起大拇指是很容易让人接受的，但如果你在阿富汗，伊朗，尼日利亚，或者是意大利和希腊的一些地区旅行，你要注意了，在这些国家，这个手势是极度的粗鲁和侮辱人的。在撒丁岛，竖起大拇指是很具有攻击性和挑衅意味的，一个远足旅行者举起大拇指表示叫人走开，而不是要求搭车。
一般来说，在这些国家，这个手势和在英国美国通用的“中指”手势意思是一样的。
现在“竖起大拇指”这个短语常被用于英语演讲，如“导演向我竖起大拇指”。而在那些不接受这个手势的国家，如果是在正式的情况下，那么这个短语也是可接受的。
因此，在你去一个国家之前，先调查一下它“竖起大拇指”的传统用法以及其它的一些手势是值得的。它能让你避免一些麻烦，至少增加了你在撒丁岛搭车的机会。