As usual, the U.S. played a key role in fostering international cooperation. You see, in 1916, Americans from a bunch of engineering trade groups founded the American National Standards Institute, or ANSI. The trade groups were getting a bit ANSI about the lack of a regulation width for pipe threads. (A real problem! It made it difficult to coordinate on major public works initiatives.) Eventually, ANSI built a set of regulations for industrial workplaces and building projects, and helped make formerly dangerous production and construction jobs much safer for workers.
After World War II ended, there was a major push towards international cooperation on foreign policy issues, one that resulted in (for example) the founding of the U.N. In 1947, a group of highly detail-oriented humanitarians got together in London to found the International Organization for Standardization, or ISO. A representative from ANSI attended, as did representatives from each of the 25 then-member nations.
The brave men and women of the ISO risked potentially morbid levels of boredom to create guidelines for everything from environmental best practices to industrial quality assurance. But the ISO was not content to just make invisible rules about stuff. They wanted to make stuff you could see with your eyes. And so they created many, many sets of symbols for use in safety and informational signs, designing them to be universally intelligible and culturally neutral.
But what about the plane part? Well. The first commercial air flight in U.S. history had happened many years earlier, on January 1, 1914. (It went from St. Petersburg, Florida, to Tampa.) The first aviation safety laws were passed in the 1920s. International travel took off in the 1940s.
You can keep your free airplane ham dinner, three-color-process people of the past. We may have to pay for every crumb of food they give us, but at least we have those inflatable life-vests that we don't know how to use because we never actually watch the instructional video. Take that! (dok1/Flickr)
In the past few decades, however, the industry has grown at an exponential rate. (In April 1997, about 40,000 flights left the U.S. for international destinations. Just 15 years later, in April 2012, about 70,000 did.) And foreigners sometimes fly U.S. domestic air, too! Unsurprisingly, there has started to be a really good chance that, at any given time, there are a lot of people in the sky on American planes who do not speak the same language.
What did the ISO do about it? Regulate! The ISO 9000 family of graphical symbols (approved over the course of the past decade) are what you see on most U.S. planes everyday.
These upside-down exclamation points keep you safe. But they are also having fun.