Of the 50 females surveyed, 45 reported that width felt better, with only 5 reporting length felt better (chi square = 32.00, df = 1, p < .001). No females reported that they could not tell any difference. Some did report that sex in a relationship was better than sex without commitment.
Masters and Johnson [1
] have said that penis size should have no physiological effect on female sexual enjoyment, since the vagina adapts to fit the size of the penis. The current results call this conclusion into question, and point to the importance of penis width. However, Masters and Johnson could be correct if the present subjects are only reporting their psychological preference, and not showing a true physiological preference. In other words, the present study solely assessed females' perceived level of sexual satisfaction, which might differ from actual physiological arousal and satisfaction.
It is not obvious why a wide penis would be preferred to a long penis, but speculation would suggest the following. Penis width may be important due to a penis thick at the base providing greater clitoral stimulation as the male thrusts into the female during sexual intercourse. That is, a wide penis would seem to offer a greater degree of contact with the outer part of the vagina, including the clitoral area. If this is correct, then Masters and Johnson are wrong about penis size being unrelated, physiologically, to female sexual satisfaction. Masters, Johnson, and Kolodny [3
] do not totally rule out penis size being relevant, but they suggest that it is likely of minor importance for female sexual satisfaction (see especially pages 509-510 in Masters, Johnson, and Kolodny [3
]). Another possibility is that a wider penis provides the woman with a greater feeling of fullness, which is psychologically, and perhaps physiologically, satisfying.
Further research on sex is necessary to understand the various influences on sexual attitudes and behavior, including how attitudes influence behavior, if, in fact, they do [4
]. Different samples could be studied, as well as using different methods of investigation. One might have women rank order different aspects of sexual satisfaction, including such things as physical attractiveness of the partner, romantic feelings, love, and other things, as well as penis size. This would give an understanding of where the different attributes rank in women's stated preferences. But, width vs. length deserves study.