Freud says fetishes, at least in men, are caused by early childhood trauma. The guy I'm dating now firmly believes that I was traumatized in some way that lead to me eroticizing hair washing.
Personally, I'm not a fan of Freud's work. I've had to read Anne Koedt's "The Myth of the Vaginal Orgasm" for, oh let's see now, four classes? Yeah, that sounds about right, maybe five, but you get the idea. I know Freud was wrong in his notion that the vaginal orgasm is more "mature" than the clitoral orgasm. I could go on and on about this, but I'll save that for another time. Perhaps another blog entirely. But if Freud was wrong about that, I'll stand to wager he was wrong about a few other things.
We've also taken significant strides to dismantle the myth that all homosexual tendencies are caused by childhood trauma. Most of the time they're just . . . there. And maybe we don't need to know why people are gay, and spend more time and energy just accepting people for who they love.
If I was traumatized as a kid, I can't remember it. At least, nothing that can be linked to this fetish. Maybe I developed a weird obsession with it as a kid for whatever reason, maybe from watching some kids' movie, and then it developed into an erotic fixation when I saw the Herbal Essences commercials.
Why do we need to pathologize every little abnormality? By that I mean, do we have to classify everyone who's just a little bit "off" as sick or broken? Unless someone's weirdness causes a legitimate problem for themselves or others, leave it alone!
There are some fetishes I think may arise from deeply entrenched sexism - like a fascination with anything having to do with dominating a woman, or the preference for very young girls even if the guy is much older. And maybe this shampoo fetish is steeped in gender norms too, maybe I've eroticized being taken care of by a guy, or many guys. The model of a woman submitting to a man in exchange for being taken care of is hundreds of years old, and was only very recently challenged in most of the developed world, where the concept of feminism is easily accessible.
In this day and age, I think one's fetishes have much more to do with the media they're exposed to than anything else. We're in a media age, where adolescents turn to the media and their peers rather than parents and teachers to learn about, well, everything. Most guys learn about sex through pornography, girls through magazines, and everyone is exposed to pornified images in advertising, movies, television, and music videos. Kids who don't learn through the media learn through their peers, but the ideas that seep into the peer culture of teens are from various forms of media. I'm sure that many fetishes probably developed from whatever an adolescent's first exposure to eroticism was, whether that was through pornography or through sexual advertising.
Early childhood trauma might be a cause or contributing factor for some people's sexual abnormalities, but I think fetishes come more from early exposure to eroticism, socialization and education of what is pleasurable, and maybe even mere childhood experiences. Whatever the cause, as long as it's not hurting anyone, maybe we should just leave it alone and embrace what makes us different, whether than fret over why we deviate from the norm.