[CN: CSA mention in first paragraph]
As a young and impressionable undergrad, the first academic book on bisexuality I came across in my university library (I have carefully blanked both the author and the title from my mind) argued that being abused as a child led to women becoming bisexual as adults. Even as recently as 2011, researchers at Northwestern University in the US felt the need to “validate” the existence of bisexual men – a move which prompted much snark from said bisexual men.
The outputs of research on bisexuality are often questionable largely because the assumptions and methods behind them tend to be flawed. As an academic in a related field, I occasionally get a glimpse at how the sausage is made: Researchers often circulate their questionnaires on various scholarly LGBT mailing lists in the hope of attracting more respondents, and I have got into the habit of vetting them before inflicting them on my unsuspecting queer friends and acquaintances. Surveys ostensibly aimed at the LGBT community almost invariably will contain a question along the lines of “When did you realise you were gay?” (I tend to return essay-length responses on why I am not “gay” and bin the link.)