Without sounding too....well creepy or gay, i enjoy watching docs on african tribes and one thing i noticed is that no most of them aren't at all very big, in fact the largest penis seen is often the white english narrator/presenter when he joins in certain activities that require him being nude.
But one thing i have noticed with eastern african tribes in comparison to west african tribes is that some (more than your average before anyone says 'huge generalisation') tend to have skinny long looking penis'. East africans are among some of the tallest men on the planet, especially in comparison to stout west africans, Hydromaxmm penis almost matches physique in this case. The Masai is perhaps a famous example, they have very long limbs in comparison to almost any other peoples....
example..
^^^^and that's just a kid, the length of his fibula and tubular is crazy. lol a lil off P.E topic but still.
and maybe some SSJs!