Sorry fellas, contrary to what a gal might tell you, size does in fact matter.
A study done by a researcher at the University of Ottawa found that penis size has a measurable influence over whether a woman finds a man attractive.
"We found that flaccid penis size had a significant influence on male attractiveness," concludes the study, published Monday in the Proceedings of the National Academy of Science.
"Males with a larger penis were rated relatively more attractive."
Comparatively speaking human males are "generously" endowed, which drew biologist Brian Mautz to explore how the size of male's private parts is based in science.
"Another project I was on, looking at female preferences in genital size in fish, showed that females actually do discriminate in males before copulation even begins," Mautz said. "That potentially influences genital evolution."
While previous research asked women to choose between drawings of male anatomy they found appealing, Mautz believes self-censorship would bias the data.
"When you directly ask someone about a sensitive topic, you're likely to get some bias in responses," he said. "Penis size isn't supposed to matter."
The study compared 343 combinations of body shape, height and penis size varying from smaller to larger. Women were then asked to rate computer-generated, life-sized pictures of the naked male on sexual attractiveness.
Mautz found that men who were tall, long and V-shaped were scored with the highest levels of attractiveness. Body shape was the most influential variable, followed by penis size and height.
"The finding suggests that selection on penis size is potentially as strong as selection on stature," he said.
The study found, however, that bigger isn't necessarily better – and it didn't look at other physical or emotional traits that factor into perceived attractiveness.
But, says Mautz, "It shows that females can exert a choice and influence genital evolution, which is a relatively understudied area."