Being of northern European descent, we men didn't waste too much time talking about, or even bragging about the size of our dicks, or how that size affects our virility!
This is not an indication of anything other than a disinterest in how the size of our 'Johnson' could dictate how we perceived each other in a 'manliness' sort of way ......., but apparently this is not the norm among a lot of different societies around the globe! (Perhaps it's because our private parts are hidden under several layers of clothing, which makes it harder to get at our dicks, while down south men's bodies are less and less constrained by clothing as the temperature rises.)
Whatever the case it seems that a man's "machismo" increases in direct proportion to how close to the equator he lives!
As we travel south, the first instance we see of men grabbing their balls occurs among the Italian and Spanish population, and there seems to be a specific reason for this.
In ancient times, Roman men would swear oaths on their balls.
Testicles. Testify. See? In effect they grab their balls to announce that what they just said is true, or as true as they want it to be.
Next come the men from the middle East, who have an unholy fixation on the size of their genitals, and on top of constantly grabbing themselves they will spend an inordinate amount of time trying to convince everyone around them that they really do have the largest dicks!
And last, but certainly not least, comes the blacks of sub-Saharan Africa who know they have the biggest dicks and don't even bother to advertise it .........., they just walk around trying to fuck every female they can get their hands on! (For us Northern European types, it gives us a bit of solace and lessens our feelings of inadequacy when we see a diagram like THIS one!)