Here’s a chapter from my Disinformation-published book titled 50 Things You’re Not Supposed To Know: Volume 2 (2004):
It’s long been noted that all of us start in the womb as sexless little blobs. We each had the same undifferentiated external equipment (a bud of tissue), plus two sets of internal ducts.
Depending on whether an embryo has a Y sex chromosome or two X’s, during week seven it starts developing into a boy or a girl. That little mound of tissue (the genital tubercle) either opens to form two sets of labia and a clitoris, or it closes to make a penis and testicles. When viewed this way, the similarities between guys’ and dolls’ private parts is obvious and has drawn comments since ancient Greek times.
But there’s a whole lot more overlap than you might suspect. Women aren’t the only ones who have a clitoris. Men do, too.
To fully understand this, it helps to know some things about our naughty bits. In women, the clit is a much larger organ than it generally gets credit for being. That little bit of ultra-sensitive tissue that is the target of so much attention is merely the tip of the iceberg. The visible part that is touched and tasted is the crown, typically 0.25 to 0.75 of an inch in length. Hidden from view is the other 2.75 to 5 inches of the structure! The entire thing is shaped like a Y, with the visible crown leading to the section called the body, which then splits into two legs that hug the urethra and vagina canal.
This 3- to 5.75-inch structure is made of two sandwiched strips of corpora cavernosa, a tissue that engorges with blood and stiffens when its owner is aroused.
Turning to the penis, we see that its insides are made up of two kinds of tissue. The thin corpus spongiosum runs along the underside of the shaft, enveloping the urethra, and accounts for all of the head. This tissue plays a minor role in erections, since a hard-on is due mostly to the two sandwiched strips of corpora cavernosa, which comprise the bulk of the shaft. These taper off internally right as they reach the spongiosum dickhead.
As in women, a man’s cavernosa soaks up blood and becomes erect when sexually excited. As in women, the cavernosa is shaped like a Y with three parts — crown, body, legs. In the case of men, the body accounts for more of the structure, and the legs are relatively stubby. On average, the male cavernosa is typically longer and thicker (which makes sense, since men as a group are bigger than women), and — unlike women — the majority of it is visible.
So here’s what we have: the same tissue forming the same structure in the same place. In other words, it’s the same thing.
A penis is really a clitoris that’s been pulled mostly out of the body and grafted on top of a much smaller piece of spongiosum containing the urethra.
As much as I’d like to be known as the person who first realized that men have clits, the credit goes to psychologist-anatomist-sexologist Josephine Lowndes Sevely for first making this explicit in 1987. Science writer Catherine Blackledge expanded on it in 2004.
References: “Male Clits.” Blackledge, Catherine. The Story of V: A Natural History of Female Sexuality. Rutgers University Press, 2004. § Gray, Henry. Anatomy of the Human Body. 20th ed., rev. and re-edited by Warren H. Lewis. Philadelphia: Lea & Febiger, 1918. § Sevely, Josephine Lowndes. Eve’s Secrets: A New Theory of Female Sexuality. Random House, 1987