"The famous sex researchers Masters and Johnson have concluded that size of the male penis can have no true physiological effect on female sexual satisfaction. They base this conclusion on their physiological studies that show that the vagina adapts to fit the size of the penis. Because of this vaginal adaptation, they refer to the vagina as a potential space rather than an actual space. Thus, despite the worries of many males about the size of their penis, Masters and Johnson concluded that any size penis will fit and provide adequate sexual stimulation to the female."

/Research article "Penis size: Survey of female perceptions of sexual satisfaction", Russel Eisenman/