Zheng Zhongjie, Chen Yan, Zhang Wei, Chen Qianxi, Liu Zhen, Chung Eric, Hong Kai, Lin Haocheng
Department of Urology, Peking University Third Hospital, Peking University, Beijing 100191, China.
Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191, China.
Sex Med. 2025 Sep 10;13(4):qfaf068. doi: 10.1093/sexmed/qfaf068. eCollection 2025 Aug.
Despite the significance of penile dimensions in male health and self-perception, there is a lack of population-specific references and understanding of self-assessment biases.
To establish population-specific references and investigate self-assessment biases in penile dimensions.
A single-center cross-sectional study (2024-2025) prospectively enrolled 342 Chinese males. Standardized measurements of flaccid and stretched lengths were performed by a trained andrologist. Participants were asked to report their perceived erect penile length, and stratified into three mutually exclusive groups: (1) accurate estimation (AE), where self-reported lengths = stretched lengths; (2) overestimation (OE), where self-reports > stretched lengths; and (3) underestimation (UE), where self-reports < stretched lengths. The penile lengthening ratio (PLR) was calculated as (stretched - flaccid length)/flaccid length. Statistical analyses included paired tests and one-way analysis of variance for multigroup comparisons.
Mean flaccid and stretched lengths, self-reported lengths, and the distribution of estimation groups were determined.
Mean flaccid and stretched penile lengths were 7.27 ± 1.60 and 11.89 ± 1.57 cm, respectively. Self-reported erectile lengths (12.81 ± 1.85 cm) significantly exceeded measured values ( = 0.92 cm, < .001), with 72.81% of the participants overestimating their erectile length. OE participants exhibited greater flaccid (7.46 ± 1.64 vs 6.74 ± 1.39 cm, < .05) and stretched lengths (12.01 ± 1.47 vs 11.46 ± 1.69 cm, < .05) than AE participants. UE individuals showed paradoxically higher stretched lengths (13.50 ± 2.38 vs 11.46 ± 1.69 cm, < .05) and PLR (97 ± 36% vs 71 ± 14%, < .05).
These findings provide critical references for clinical counseling on penile size and perioperative doctor-patient communication, potentially alleviating patient anxiety stemming from cognitive biases to a certain extent.
The strengths include standardized measurements and a clear classification of estimation group. The limitations include incomplete baseline data (lacking penile circumference, smoking history, etc.), single-center small-sample bias, inevitable selection bias, and absence of partner satisfaction data and validated assessments.
This study revealed that self-reported erect lengths among adult males were significantly longer than clinician-measured stretched lengths. OE participants accounted for more than 70% of the sample, while UE participants tended to have a greater PLR. The research provides reference ranges for flaccid and stretched penile lengths in Chinese males, offering objective data to support clinical counseling and surgical communication. This not only alleviates patient anxiety rooted in cognitive biases but also elucidates the potential association between penile size misperceptions and PLR.
尽管阴茎尺寸在男性健康和自我认知中具有重要意义，但缺乏针对特定人群的参考标准，且对自我评估偏差的了解不足。
建立针对特定人群的参考标准，并调查阴茎尺寸的自我评估偏差。
一项单中心横断面研究（2024 - 2025年）前瞻性纳入了342名中国男性。由一名经过培训的男科医生对疲软和拉伸状态下的阴茎长度进行标准化测量。参与者被要求报告他们自我感知的勃起阴茎长度，并分为三个相互排斥的组：（1）准确估计（AE），即自我报告的长度 = 拉伸长度；（2）高估（OE），即自我报告的长度 > 拉伸长度；（3）低估（UE），即自我报告的长度 < 拉伸长度。阴茎延长率（PLR）计算为（拉伸长度 - 疲软长度）/疲软长度。统计分析包括配对t检验和用于多组比较的单因素方差分析。
平均疲软和拉伸阴茎长度分别为7.27 ± 1.60厘米和11.89 ± 1.57厘米。自我报告的勃起长度（12.81 ± 1.85厘米）显著超过测量值（差值 = 0.92厘米，P <.001），72.81%的参与者高估了他们的勃起长度。与AE组参与者相比，OE组参与者的疲软长度（7.46 ± 1.64厘米对6.74 ± 1.39厘米，P <.05）和拉伸长度（12.01 ± 1.47厘米对11.46 ± 1.69厘米，P <.05）更大。UE组个体的拉伸长度（13.50 ± 2.38厘米对11.46 ± 1.69厘米，P <.05）和PLR（97 ± 36%对71 ± 14%，P <.05）反而更高。
这些发现为阴茎尺寸的临床咨询和围手术期医患沟通提供了关键参考，可能在一定程度上减轻患者因认知偏差产生的焦虑。
优点包括标准化测量和估计组分类明确。局限性包括基线数据不完整（缺乏阴茎周长、吸烟史等）、单中心小样本偏差、不可避免的选择偏差，以及缺乏伴侣满意度数据和经过验证的评估。
本研究表明，成年男性自我报告的勃起长度显著长于临床医生测量的拉伸长度。OE组参与者占样本的70%以上，而UE组参与者的PLR往往更大。该研究提供了中国男性疲软和拉伸阴茎长度的参考范围，为支持临床咨询和手术沟通提供了客观数据。这不仅减轻了患者因认知偏差产生的焦虑，还阐明了阴茎尺寸认知错误与PLR之间的潜在关联。
