I have been thinking a lot about sign language, as my mother is rather deaf, and I am already beginning to lose my hearing. This rather dismays me, as I was already wondering if I would need to learn ESL or French, or whether one would follow easily from the other!
It also reminds me that counting on fingers in China is very different, (perhaps in Japan, too?) and so maybe the people didn't begin to count until after settling in Asia...which seems probable. Although if there is so much variation in one smallish island?