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.