Hahaha interesting study, this sorta confirmed some stereotypes yet raised many questions. For example:
1/ Are they even sure that the US is around 5.1 inches?? Lol, I thought it would be bigger than that like around 5.6 inches?? Lol US doesn't look that HUNG compared to the rest of the world. LOL
2/ Didn't Japan published a Penis study a while ago stating that most Japanese men are around 5.2 inches >> US men at 5.1 inches? (South park's reference anyone??) lol
3/ I watched a couple of Brazilian/latin/czech bel ami porn, ok, damn those guys are HUNG! lol (Confirmed stereotypes).
4/ Does this apply to Minorities (Latino, Black, Asians) in western countries or just people in their own countries??. For example, Peter Le, the Vietnamese guy model is around 6.7 inches, yes I've seen his naked pics. And one of the guys I've been with who was sorta disappointing in bed was about 3.5 inches and he was like Irish-American/white guy. Lol, I feel normal according to this as I am right in the middle between England and France which would explain I don't have any complaints from dudes in my past sex hook ups. LOL, Ok that sounded Slutty.
5/ For some reason, I like guys around 5.4 to 6 inches, sorta similar to me and same body type.