This Is What Science Says About "Size Matters"

Like a vampire (or a particularly stubborn erection), the size matters myth seems to rise from the dead despite repeated attempts to snuff it out for good. The idea that women only like 'em large is highly problematic — and often wrong. Penis size is but one of a variety of factors that are taken into account during a sexual engagement, and yet, there are still plenty of penis-havers who define their worth based upon their size.

Playing upon the trope of "bigger is better" — and that men love to lie about their dick size — the American Scientific Measurement Corporation (yes, that's their name) just released a novelty measuring device called the Original Dick Ruler. This 9-inch wood ruler printed to 12-inch specifications makes your wood look 30 percent bigger when held up against it. Clearly, this is an ideal stocking stuffer for the guy who takes himself too seriously (or the one who definitely doesn't).

Beyond the myth and the gag gifts, however, why are we still stuck in this size matters mentality? Here are six stats from studies and surveys about heterosexual men and penis size that reveal the real extent to which size matters:

1. Men Comfortable With Their Penis Size Have More Sex

A study published in the Archives of Sexual Behavior used the "Index of Male Genital Image" to study how men feel about their penises. Unsurprisingly, the key to a satisfying sex life isn't a massive penis, but self-acceptance (cue after school special music). Regardless of age, race, sexual orientation, education, location, or income, researchers found that men who were dissatisfied with their genitals were more likely to have less oral and less penetrative sex than men who were satisfied with their penises.

2. Most Millennial Women Don't Care About Penis Size

According to a survey of 1,100 Cosmopolitan readers between the ages of 18 and 34, Millennial women aren't lying awake at night worrying about their BF's dick size. A whopping 89 percent said they didn't have an issue with what their partner is packing, even though only 33 percent classified their partner's penis as on the large side.

3. Desired Size For One-Night Stands Versus Relationships Differs

A study published in the journal PLOS One looked into women's preferences for penis size using 3D models. Female subjects were exposed to a variety of erect penis models and asked which they would prefer for a one-time sexual encounter, and which they would prefer for a relationship. Interestingly, women chose a slightly larger length of 6.4 inches for a fling, but a slightly smaller 6.3 inches for a LTR.

4. Porn Penis Sizes Can Make Young Men Feel Inferior

Although porn is certainly not the cause of all of mankind's ills (as some suggest), it can set unrealistic expectations for young men. Besides the fact that much of mainstream porn is created to satisfy the male gaze and male fantasies (which is not the case of IRL sex), the average male porn star's penis is 8 inches long erect, while the average man's penis is 5.8 inches long erect. According to Psychology Today, watching porn at a young age can cause boys to believe "that men and women's bodies should be sexually exaggerated as they are in porn — which can lead to shame about one's own body as well as failure to be aroused by the bodies of others."

5. Size Does Matter For Fertility

OK, so maybe the "size matters" saying is right — but only when it comes to sperm count and the distance between the anus and the scrotum. A study in Environmental Health Perspectives analyzed average anogenital distances and found that when they fall below the median length of 2 inches, a man is more likely to be sub-fertile, which generally indicates a sperm count of less than 20 million per milliliter.

6. Girth Is More Valued Than Length

It's important to note there is no study proving that women think size matters across the board, but women do apparently care more about girth than length. According to research by the University of Texas, 90 percent of women surveyed said that circumference is more likely the key to maximum pleasure. Still, there are no hard and fast rules about how a hard penis should look. Variety is, after all, the spice of life.

Images: Andrew Zaeh for Bustle; Giphy (6)