When I was in Japan for a brief student-exchange, we (the American students) and the Japanese students were all asked to
raise our hand if we know a teenager who was/is pregnant.
Several of the Americans raised their hand, and NONE of the Japanese kids did.
We were also asked if we knew a teenager who had had an abortion; several of us raised our hands but once again NONE of the Japanese students did.
I don't think it was dishonesty... I just don't think they're having sex.