Your Most Surprising Erogenous Zones

The most intense erogenous zone the human body possesses is an entire organ—in fact, it's the largest organ, and it's probably out for all to see right now. Fine, fine! You caught us: It's the old "your epidermis is showing" joke. We are, of course, talking about your skin.

"The skin is the largest organ on the body, making it the largest sex organ we have at our disposal," said Kate Delgado, resident sex educator at Lioness. "Becoming aroused by touching places like your wrists, behind the knees, your feet or your belly are absolutely normal. More often than not, these unexpected erogenous zones are simply just a matter of being unexplored."

Every erogenous zone, from the scalp to the inner elbow, is normal. In fact, sex educator Edwina Caito explained how these areas can be even more prone to sparking arousal.

"The thinner the skin, the more sensitive that area will be, which is why most people are easily aroused by stimulating the neck, wrists, inside of the elbow and the bend of the knees," Caito explained. "Add to that the positive brain connections made from past touch and you have an entire body teaming with erogenous potential!"

Where the action really happens: The brain

Your erotic response isn't anchored to one spot in your body but is rather determined, in part, by how sensitive a body part is. Neuroscientist Nicole Prause, Ph.D., specializes in the physiology of sexual responses and explained how our brains are built in a way that facilitates sexual responses from areas of the body not considered conventionally sexual.

"The genitals are represented in different areas of the motor strip, as each area of the body has its own space on that strip of cortex," Prause said. "The responses to genital stimulation rely on the same networks as other positive, pleasurable emotions, like joy. The cingulo-opercular network is a primary source of processing sexual stimulation, whether it comes from the genitals or non-genital skin."

Prause's explanation involves one big new vocabulary word. The cingulo-opercular network is a mental superhighway with debated functions. It's hard to say exactly what the cingulo-opercular network does because it's difficult to define what it doesn't do. However, this ambiguity serves our purposes—sexual and "non-sexual" functions share office space in our minds.

For instance, the cingulo-opercular network takes residence in zones speckled throughout the brain. The network spans from the thalamus—located in the center of the brain—to cortexes and lobes bookending both sides of our brains. In line with this decentralization is the fact that the cingulo-opercular network seems engaged in a variety of tasks ranging from word recognition to processing stimulation.

The skinny on skin

Assuming any body part is capable of sexual response, you may be wondering why the skin is so special. Mainly, this is due to C-afferent fibers, or nerve fibers carrying sensation to our brains. As the name suggests, there are also A- and B-afferent fibers. And just when our erotic response was beginning to sound easily conjured, Prause clarified how particular our nerve endings can be.

"The main distinction is that the skin has specialized C-afferent fibers that respond to slow-moderate stroking speeds as erotic," she explained. "For whatever reason, C-afferent fibers prefer fine to moderately slow stroking by an ungloved human hand. It does not work with a robotic hand. It is blunted almost entirely when a human hand is covered with a glove. Too fast? No activation. Too slow? No activation. [C-afferent fibers] are found throughout the hairy skin on the body and seem finely tuned to the perception of sexual arousal."

If the boundary between sexual touch and, say, a handshake isn't all that defined, what then separates an erogenous zone from a fetish?

'The skin has specialized C-afferent fibers that respond to slow-moderate stroking speeds as erotic.'

"A 'fetish' actually is a pretty high bar where the person cannot function as they wish sexually without the involvement of that body part," Prause said. "Higher sensitivity to one particular body part is never, alone, a fetish."

Even unsurprising erogenous zones still may have interesting explanations. Kelly Nolan, the owner of online sex toy vendor Lush Sensations, explains why the bikini line, for instance, is so sensitive for those of us possessing a clitoris.

"One of the most surprising erogenous zones for female arousal is the area between the belly button and pubic area—your lower stomach," Nolan said. "It's located just a few inches from the clitoris. And by using just the right pressure or feeling the right vibrations, you can stimulate the G-spot indirectly from the opposite side."

As a professional experienced in tracking sexual response in a laboratory setting, Prause said the single most surprising erogenous reaction is a lack of response at all.

"The bigger surprises are often where people do not feel aroused," she noted. "People who cannot stand to have the head of their penis touched or their nipples feel 'dead.' The physiology is supposed to make certain areas process as sexual, but they do not seem to always connect."