I woke up thinking about Glory, Devin O'Branagan's book in the vampire genre.I realized that there's an oxytocin story here.
O'Branagan creates a world with an even more complex set of races than Stephenie Meyer's Twilight series.
Twilight's Bella has to choose between Jacob the werewolf and Edward the vampire -- and that's no decision at all. As she tells Jacob in the firs tmovie, "Don't make me choose, because it will always be him."
In Glory, Glory, the heroine, finds out that there are all sorts of races living with humans, sometimes helping, sometimes fighting, sometimes ignoring them. Glory is torn between two romantic interests, Zane, a vampire, and Dominic, an angel. She's deeply moved by and attracted to both of them in different ways.
(For more about the psychology of vampire love, read Fangs, Blood and Romance -- Oh My!)
Glory has an intense attraction to each of them. With Zane, it's blood-boiling lust. When he touches her or kisses her, her whole body ignites. With Dominic, she seems to sink into a blissful sense of union with , feeling deeply connected.
That sounds like testosterone vs oxytocin to me. Vampire Zane, who is also a cowboy, incites testosterone-fueled lust, while angelic Dominic evokes the release of calmly connecting oxytocin.
While Twilight's Jacob is very sweet and Edward is super-sexy, I can also see the oxytocin/testosterone contrast in them. Especially in the movies, Jacob has the superb muscles of a high-testosterone, alpha male. Edward, on the other hand, exhibits more oxytocin traits: He is sweet to Bella, is part of a family and community that is close and bonded, and he advocates for peace among all beings. (He's also more "pretty," especially when he sparkles.)
So, it's very clear why, for Bella, "It will always be Edward." And it's clear to me whom Glory should choose.
Nature seems to have intended that hot lust to get us over our fear of strangers and cause us to have lots of sex. But that sex is supposed to release oxytocin, which creates a deep and long-lasting bond -- long-lasting enough to keep us together when lust inevitably fades.
Glory should choose Domenic. I'd bet that in the final installment of the Glory saga, Zane will sacrifice himself to save Glory. Is there a future for human Glory and angelic Dominic? Who knows?