Sexual Orientation and Sexual Activity

In response to the question, "Do you think of yourself as heterosexual, homosexual, bisexual or something else?":

90% of women said they think of themselves as heterosexual
1.3% of women think of themselves as homosexual
2.8% of women think of themselves as bisexual
3.8% of women think of themselves as "something else."
Among women who have had sexual relations with another woman, nearly two-thirds (65%) consider themselves heterosexual.
The NSFG concedes that further study is needed to determine what exactly "something else" means to these women. They speculate that women may not understand those terms, or prefer some other term to describe their sexual orientation.

The percentage of men and women who think of themselves as bisexual or homosexual is roughly equal at 4.1%. This represents 2.27 million men and 2.29 million women in the United States.

Who are Women attracted to?

86% of women said they were attracted to only males
10% said they were attracted to "mostly males"
3.4% of women said they were attracted to only or mostly females, or equally attracted to males and females.
It is important to note that these studies do not include those 45 years of age or over, those in prison, jails or other institutions, so they are not complete estimates of the total number of people in the United States.

The Northwestern study strongly suggests this is true. The Northwestern researchers measured the psychological and physiological sexual arousal in homosexual and heterosexual men and women as they watched erotic films. There were three types of erotic films: those featuring only men, those featuring only women and those featuring male and female couples. As with previous research, the researchers found that men responded consistent with their sexual orientations. In contrast, both homosexual and heterosexual women showed a bisexual pattern of psychological as well as genital arousal. That is, heterosexual women were just as sexually aroused by watching female stimuli as by watching male stimuli, even though they prefer having sex with men rather than women.