Written by Emily Nagoski, Ph.D.
Which brings me to foot fetishes.
There are lots of stories about the various fetishes in the world, and there are very many, and very varied fetishes. Every body part, every fluid, and every social phenomenon can be eroticized. But the foot fetish is one that I think is quite simple to explain, or as simple as anything so rare and complex can be.
My explanation is this: The somatosensory homunculus (a favorite phrase of mine because it's fun to say and makes you sound like a real smarty pants too) is the sensory map of your brain in your body. You'll notice that the feet are immediately adjacent to the genitals. So even though your feet are at one end of you actual body and your genitals are in the middle, as far as your brain is concerned, they're right next to each other.
A phenomenon known in the nerd world as "spreading activation" takes us the rest of the way along this story. The foot sensation part of your brain "lights up" and lights up a little bit of the genital part of your brain along with it, or vice versa, and suddenly there's a link between sexual arousal and foot sensations.
And so over time the guy (it's usually a guy, not always, but usually) begins to feel sexual desire around feet, in the same way that he feels sexual desire around the genitals of his partner.
This isn't a complete story, obviously. There's a lot of social stuff I'm not even mentioning, like it's probably only a small part of the explanation for the role of the car in the pedal pumping fetish, but I think it's an important piece of the story. It's a piece of the story that's essentially overlooked in the Daily Beast's take on things.
Similar stories, from my point of view, account for feces or urine fetishes, smoking fetishes and fingernail fetishes. Body parts and sensations not necessarily linked with sex come to be linked through accidents of spreading activation and associative learning.
Mmmmmh, spreading activation...