Growing up I thought cooties (http://www.youtube.com/watch?v=w6ylxWcwkUM) were real and I knew exactly what they looked like

http://i3.ebayimg.com/08/i/000/c4/5f/a184_1.JPG.

Is it only an American thing? Where did it come from?

Cootieville, in Cootieville Hollow just outside Cootie, B.B.:D

When I was in grade school...we would "spray" a chair a girl sat in with make-belief cootie spray. They are very contagious!

LOL, and then what??
Have you ever heard of the cootie vaccination shown in the cootie video?

I remember making "cootie catchers," although I never got a "cootie shot." According to Wikipedia and corroborated by other sources: The word "cooties" came into English during the American occupation of the Philippines in the first half of the twentieth century. Kuto or something close is the word for head or body lice in most of the Austronesian language family, including Tagalog and many other languages of the Philippines. Head lice became enough of a problem for the occupying troops that they picked up the word kuto and built an artificial plural form "cooties," which was adopted as North American English slang. The sources bemoan the difficulty of tracing the routes by which words enter childrens' slang, but I have no problem imagining a G.I. dad giving his little boy or girl a "noogie" (now where did that word come from?) and justifying it because he was sure he saw "cooties" on his or her head. Such a deliciously silly-sounding word with such a deliciously icky meaning, what kid wouldn't spread it like cooties across the whole schoolyard? :)

The Brits have a roughly similar but not identical term, "lurgi" (with a hard G), and they also use the word "mange," which is a perfectly respectable veterinary term in the USA, in a similar fashion. Other northern Europeans have similar words but, oddly, in northern Europe only girls can be infected.

I always connected cooties to boy germs and not lice.
They could breathe cooties on you. Or apparently spray them on your chair. lol

I always connected cooties to boy germs and not lice. They could breathe cooties on you. Or apparently spray them on your chair. lolWell sure. Lice are pretty difficult to see, so the word just came to mean any invisible disease-bearing organism. :)

It was a convenient way for younger children to start enforcing segregation of the sexes.