There is one interesting correlation. However, we may never have the proof that the sexagesimal base is a consequence of it. But it's a fucking correlation.

12 is the biggest number you can reach counting with one hand. 60 is the biggest number you can count to with your 2 hands.

Let me explain the 12:

Your thumb is used as a pointer of where you are with your counting. Then you count all the phalanges of your actual hand (the one you count with). 3 phalanges per finger, and 4 fingers (five minus the thumb equals 4) per hand. That make 12!

Each time you add 1 you change the position of your thumb. For example, you start with the 1st phalange of the 1st finger; then the 2nd phalange of the same finger; then the 3rd of the same finger; and you do the same for the 2nd, the 3rd, and the 4th finger. Easy, isn't it?

And for 60:

With the other hand you can count to five. 1 is your hand fully opened. And for the other 4 (2, 3, 4, and 5), you mark each other fingers with your thumb as a marker.

This intuitive counting, as you don't need to know the numbers for counting, should have appear far before the invention of numbers by the Sumerians.

It is still in use today, at least up to 12 to do Pranayama (breathing exercises), counting the repetition of exercises while the other hand is used for blocking one nostril.

Amazing correlation, or amazing consequence?