So why do scientific studies disprove your bullshit then? And don't come with the made up bullshit data of worldmap. The few studies conducted in sub-saharan Africa show: nope, no difference.
Example: Tanzania
Chrouser, Kristin; Bazant, Eva; Jin, Linda; Kileo, Baldwin; Plotkin, Marya; Adamu, Tigistu; Curran, Kelly; Koshuma, Sifuni (August 2013). "Penile Measurements in Tanzanian Males: Guiding Circumcision Device Design and Supply Forecasting".
Journal of Urology.
190 (2): 544–550.
Average 5.17" erect length.
Example: Nigeria
Orakwe, J C; Ogbuagu, B O; Ebuh, G U (29 August 2007).
"Can physique and gluteal size predict penile length in adult Nigerian men?".
West African Journal of Medicine.
25 (3): 223–225.
Average 5.17" erect length.