They actually have such a thing:
It's called the Kinsey Scale.
And you'd be extremely surprised as to how much more evenly the statistics are distributed across the board
Here are some
modern statistics (although keeping in mind how difficult it is to get accurate statistics on sexual orientation and same-sex behavior):
- The Kinsey Institute Bibliography: Prevalence of Homosexuality
- In an analysis of national survey results from 2006-2008, The percentage reporting their sexual identity as homosexual ranged from 2% to 4% of males, and about 1% to 2% of females. The percentage reporting their sexual identity as bisexual is between 1% and 3% of males, and 2% to 5% of females. (Chandra, Mosher, Copen, and Sionean 2011)
- About 4%–6% of males ever had same-sex contact. For females, the percentage who have ever had same-sex contact ranges from about 4% ... to 11%–12%. (Chandra, Mosher, Copen, and Sionean 2011)
- While about 7% of adult women and 8% of men identify as gay, lesbian or bisexual, the proportion of individuals in the U.S. who have had same-gender sexual interactions at some point in their lives is higher. (NSSHB, 2010)
- In a national survey, 90% of men aged 18-44 considered themselves to be heterosexual, 2.3% as homosexual, 1.8% as bisexual, and 3.9% as 'something else' (Mosher, Chandra, & Jones, 2005).
- Among women aged 18-44 in the same survey, 90% said they were heterosexual, 1.3% homosexual, 2.8% bisexual, and 3.8% as 'something else' (Mosher, Chandra, & Jones, 2005).
- The incidence rate of homosexual desire for men is 7.7% and 7.5% for women (Laumann, Gagnon, Michael, Michaels, 1994).
- 6.2% of men and 4.4% of women are attracted to people of the same sex (Laumann, Gagnon, Michael, Michaels, 1994).
- 4% of men and 2% of women consider themselves homosexual while 5% of men and 3% of women consider themselves bisexual (Janus & Janus, 1993).
- 88.2% of adolescent youths as a Minnesota junior/senior high school described himself or herself as heterosexual, while 1.1% described himself or herself as bisexual or homosexual, and 10.7% were not sure of their sexual orientation (Remafedi, 1992).
So, the overwhelming majority of people claim to be straight, and claim not to experience same sex attraction. That percentage might go down a bit in a more accepting culture, but I suspect there is a lower bound. Being 100% gay myself (and trying to function as a heterosexual for a number of years) I don't buy that everyone is really bisexual.
As far as INFPs go, I think there are a few things that can go on in US culture:
First, I think INFP men are much more emotionally oriented than the stereotypical American male, and look for a higher level of emotional closeness with their friends.
Secondly, I think the need to maintain status and the related fear of looking gay combine to stifle friendship for US men. This is particularly unfortunate, since close friendships is correlated to things like improved quality of live, a longer lifespan and stress resilience.
Thirdly, friendships can have a romantic (if non-sexual) element to them (as in Bromance).
So, I think the first two factors combine to make INFPs stand out as wanting unusual emotional closeness with their friends for current American culture. With the third factor, it can give those friendships the overtones of something more by the desiccated standards of current US male friendship.
While none of that is normally confusing for male INFPs (except insofar as feeling out of step with the surrounding culture) I suppose a subset of young, idealistic INFPs do tend to focus on the emotional aspects of relationships at the expense of an awareness of the sexual aspects. This could, in theory, lead to some confusion given the romantic tones that friendship can have. I have a hard time seeing such confusion surviving actual sexual interaction, though.