The finding is not likely to surprise bisexuals, who have long asserted that attraction often is not limited to one sex. But for many years the question of bisexuality has bedeviled scientists. A widely publicized study published in 2005, also by researchers at Northwestern, reported that “with respect to sexual arousal and attraction, it remains to be shown that male bisexuality exists.”       

That conclusion outraged bisexual men and women, who said it appeared to support a stereotype of bisexual men as closeted homosexuals.       

I like what the bisexual lady in the article said:

Sexual arousal is a very complicated thing,” she said. “The real phenomenon in day-to-day life is extraordinarily messy and multifactorial.”       

Especially the part about sexuality being MULTIFACTORIAL