When 17th century personal correspondence was studied, it was observed that women used the evidential expression I THINK more often than men. A closer analysis showed that women also used other 1st person evidential verbs as well as the 1st and 2nd person pronouns more frequently than men. This male/female difference was maintained even in different registers, although both sexes have higher frequencies of I THINK in more intimate circumstances, such as when the informants are writing to their friends or close family members. The male/female differences in frequencies are explained as a difference in the style of communication. Women's style is more “involved” and interactive: personal point of view is frequently expressed, and both the writer and the addressee are overtly included in the communication situation. Interestingly, similar differences have also been found in Present-Day English.