No, it's not a joke. Mostly it's a cautionary tale about making sure your scientific test is really testing what you want to test.
It's a response to a 2005 study that concluded all bisexual men were really closet gays.
No Surprise for Bisexual Men - Report Indicates They Exist - NYTimes.com
In an unusual scientific about-face, researchers at Northwestern University have found evidence that at least some men who identify themselves as bisexual are, in fact, sexually aroused by both women and men.
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In the new study, published online in the journal Biological Psychology, the researchers relied on more stringent criteria for selecting participants. To improve their chances of finding men aroused by women as well as men, the researchers recruited subjects from online venues specifically catering to bisexuals.
They also required participants to have had sexual experiences with at least two people of each sex and a romantic relationship of at least three months with at least one person of each sex.
Men in the 2005 study, on the other hand, were recruited through advertisements in gay-oriented and alternative publications and were identified as heterosexual, bisexual or homosexual based on responses to a standard questionnaire.
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