So this study (looks like reliable data published in a urology journal) showed average erect penis size is 5.1" to 5.6".
{sigh of relief}
I saw another study (that I can't seem to find now) where a company who sold some pocket pussy-type thing released data that was self-reported by millions of men all over the world who were shown how to carefully measure their yogurt-slinger. If they lied and added extra size, the device wouldn't work correctly. It was pretty shocking. The abnormalities were expected; Africans averaged over 7" and Asians much less, with Koreans averaging only 3". Why in the hell can't I find this now?