For one-night stands, size does matter, but it's not penis length that women are concerned about — it's girth, a new study suggests.
In the study, 41 women viewed and handled artificial penises made on a 3D printer. The models were blue, and ranged in size from 4 inches long and 2.5 inches in circumference to 8.5 inches long and 7 inches in circumference. They were asked to pick which of the 33 models they would prefer for a one-time partner, and which they would prefer for a long-term partner.
For one night stands, women selected penis models with slightly larger girth, on average, than those they selected for long-term relationships.
But there was no difference in length between the penises they preferred for one-time partners versus those they preferred for long-term partners: In either case, women tended to choose penises that were about 6.5 inches long.
The vagina has many pressure-sensitive nerve endings that detect sensations of stretching, and these sensors may be finely tuned to detect variations in penis girth, the researchers said. A penis with larger girth may also bring the clitoris closer to the vagina during sex, which has been suggested to help with achieving orgasm.
On the other hand, longer penis length may lead to cervical pain, said study researcher Shannon Leung, an undergraduate in biology at the University of California, Los Angeles, who presented the findings last month at the meeting of the Association for Psychological Science in San Francisco.
In a second part of the new study, women were given one of the penis models and allowed to examine it for 30 seconds. They were then asked to pick that same model from a bin of 33 models, either immediately or after completing a 10-minute survey (to allow time to pass).
After completing the 10-minute survey, women tended to overestimate the size of the penis they had previously examined, the study found.