谢谢分享。我快速扫描了一下给的最后一个链接

虽然这是科学结论，虽然我并非专家，我对这个数据还是有一点疑问。
摘要：
Looking at average non-erect length, their meta-study found the average length worldwide was 9.16 centimeters (3.6 inches). In Nigeria, western Africa, the average length was 8.16 centimeters (3.2 inches), India it was 8.21 centimeters (3.23 inches), South Korea was 7.7 centimeters (3 inches), Germany was 8.6 centimeters (3.38 inches), USA was 8.85 centimeters (3.48 inches), and Jordan was 9.3 centimeters (3.66), to name but a few.
这是说疲软时的长度。
我认为疲软时的长度不能定义。因为，一个事实是，疲软的时候，长度不是一个常数。
Seinfeld里面有一集，George刚刚从比较寒冷的游泳池里爬出，换裤子的时候被一个女人看到。女人意味深长地一笑。George从此心心念念地想知道，女人是否了解，男人的那话儿遇冷后会收缩得特别短？
简言之，我认为测量疲软时的长度毫无意义。而坚挺时测量长度，至少在方法上没有毛病。