The Japanese language is unusual among major languages in the high degree to which the speech of women seen collectively differs from that of men. Differences in the ways that girls and boys use language have been detected in children as young as three years old. There are no gender differences in written Japanese (except in quoted speech), and almost no differences in polite speech, except for occasional use of wa (and except for the fact that women may be more likely to use polite speech in the first place).