book written by Arthur Guy Empey. Empey was an American who served in the British armed forces during World War I. He wrote: "Thumbs up, Tommy’s expression which means ‘everything is fine with me'." A visual example of the British use of "thumbs up" having a positive meaning (or, "okay") from the 1920s can be seen 19 minutes into the British-made silent 1927 film The Lodger: A Story of the London Fog, where the younger man examines some paper money for the older man and declares it "good" (not counterfeit) with a "thumbs up" using both hands. Popularization in the United States is generally attributed to the practices of World War II pilots, who used the thumbs up to communicate with ground crews before take-off. This custom may have originated with the China-based Flying Tigers, who were among the first American flyers involved in World War II. The appreciative Chinese would say ting hao de (挺好的) meaning "very good", and gesture with a thumbs up, which in Chinese means "you're number one". High officials in the Chinese government see it as a sign of respect. During World War II, pilots on US aircraft carriers adopted the thumbs up gesture to alert the deck crew that they were ready to go and that the wheel chocks could be removed. On modern US carriers, specific deck crew hold a thumb up to signal to the pilot and control tower that their station is OK for take-off. American GIs are reputed to have picked up on the thumb gesture and spread it throughout Europe as they marched toward Berlin. According to Luís da Câmara Cascudo, Brazilians adopted the thumbs up from watching American pilots based in northern Brazil during World War II. 21st century Senator John McCain of Arizona, when he cast the deciding vote that derailed a Republican repeal of the Affordable Care Act ("Obamacare") on July 28, 2017, used the thumbs down gesture. International usage The thumbs up signal has a generally positive connotation in English-speaking countries. However, its perceived meaning varies significantly from culture to culture. The sign is said to have a pejorative meaning in some countries, including Iraq and Iran. In Germany, France, Hungary and Finland the gesture can simply indicate the number one, in the right context. The thumbs up gesture is used on the logo of Thums Up, a popular brand of cola from India. Starting