As it's said in the wiki article, nothing has been conclusively proven. Yes, you can say that survey found "black people are bigger on average". But It is less credible than the sizesurvey.com survey because of a lack of any information on the Methodology used and other details. It only has the results. So no credibility at all, and of no use in the wikipedia article. I mean they can't even spell. Looks like a page someone quickly made up to attract viewers (searching on "penis size) to see their sex personal ads plastered all over the place.  

 If you find a better source which details that survey feel free to add it to the others in wiki article. Even then (with methodology details), it probably won't prove anything (being a self-measured study), and will only be useful noting as anecdotal evidence.  

 Same as the sizesurvey.com survey. You used a good quote which shows it's lack of credibility for showing racial size differences (this is already noted in wiki article). But the same is true of the Jakinworld survey. The sample size of Africans was too low to be of use (1.7%). So I would say both the sizesurvey.com survey and the Jakinworld survey are lacking in credibility for comparing racial sizes. I'd say we should either have both in the article (for fairness and neutrality) as weak anecdotal evidence or not have either. It is questionable.    

 Coolnurse.com doesn't even know where the survey information came from. Interesting read, but not credible. 

 If better studies and surveys are done that conclusively show "black" people are larger on average as a whole (race), then yes, that should be published whether "diet or god gave it to them". As of now, studies show too many discrepancies to make any conclusion.  

 Ok. That was a bit of a mind-bender to all contemplate. I think I need to take a break from this article. Penis Penis Penis... Blah Blah.. Heh. Good debate though. Kudos.