I vaguely recall something I read about a culture where people could take on the role of the opposite gender (men could take on spirtual roles usually reserved for women for example) if they lived as that gender. Am I misremembering, or did something like this exist?
I'm guessing you're thinking of the Two-Spirit people (who have a bunch of other names) from several Native American cultures, as they have kinda been "in vogue" lately in the news and in popular culture, there was a PBS documentary, for example. But liminal genders of some variety, or acknowledgement of the ability to take on a gender role not linked to a biological sex, occurs in many cultures all over the world in the past and now, from the hijra in India to the Femminiello in Naples.
this would be worth x-posting to /r/AskAnthropology, maybe also /r/AskSocialScience (check w/ the mods there first)
Late to the thread, but I see you haven't got many replies.
A good example are the sworn virgins of Albania.
http://video.nationalgeographic.com/video/albania_swornvirgins
Prior to the dictatorship of Enver Hoxha, one of the many communist regimes that emerged in Eastern Europe after World War Two, much of Albania followed the Kanun, a set of traditional laws. It is most famous for setting out the rules prescribing blood-feuds, but covered many aspects of Albanian life, amongst which were gender roles.
The sworn virgins were (and still are - many are still alive) woman who lived as men and were accorded the same rights and responsibilities of men. Responsibilities is the key part. Only men of the family can perform certain duties under the Kanun and if no men survive, a daughter can become a sworn virgin and take on those responsibilities.