Penis size over-reporting is more prevalent among experienced college men than in less experienced ones; may be due to a greater sense of masculinity & sexual competence and prowess by experienced men

Social Desirability and Young Men’s Self-Reports of Penis Size. Bruce M. King, Lauren M. Duncan, Kelley M. Clinkenbeard, Morgan B. Rutland & Kelly M. Ryan. Journal of Sex & Marital Therapy, https://doi.org/10.1080/0092623X.2018.1533905

Abstract: Previous studies demonstrate that many men have insecurities about the size of their penises, often resulting in low sexual self-esteem and sexual problems. In the present study, mean self-reported erect penis length by 130 sexually experienced college men (6.62 inches) was greater than found in previous studies in which researchers took measurements. This suggests that many of the men embellished their responses. Only 26.9% of the sexually experienced men self-reported penis lengths of less than 6 inches, while 30.8% self-reported lengths of 7 inches or more (with 10% self-reporting 8 inches or more). The correlation with Marlowe–Crowne social desirability scores was +.257 (p < .01), indicating that men with a high level of social desirability were more likely than others to self-report having a large penis.

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The difference between sexually experienced and inexperienced men for self-reported penis size has not previously been reported but suggests that over-reporting is more prevalent among experienced men, thus accounting for the stronger correlation in that group. We speculate that the difference between the two groups is due to a greater sense of masculinity and sexual competence and prowess by experienced men.