Sexual orientation defined as sexual involvement with members of both sexes concurrently (within the period of one year) or any sexual attraction to or involvement with members of both sexes at any time in one's life.

There is no single accepted definition of bisexuality. Some define it narrowly as sexual involvement with members of both sexes concurrently (within a twelve-month period or less). Others define bisexuality more broadly as any sexual attraction to or involvement with members of both sexes at any time in one's life. However, few people qualify as bisexual in its narrow definition. A comprehensive study, "Sex in America," conducted in 1992 by the University of Chicago, found that less than 1% of either males (0.7%) or females (0.3%) had engaged in sexual activity with both males and females within the previous year. While no statistics exist on the numbers of Americans who fit the broad definition of bisexuality...