Considering that white people constitute 60.1% of the USA's population, spics 18.5% and niggers 12.2%, the fact that Mexico has a noticeably higher average penis size (at 5.87 inches) than the USA (at 5.35) implies one of the following:
>Niggers are lying about their penis size.
>White boys have such tiny penises that despite almost 40% big-dicked niggers and spics, they singlehandedly lower the national average to lolcow levels (below fucking India LOL)
Personally, I think it's a little bit of both.