What is this intelligence

Two Italian construction workers were in the field on an extremely hot day working...

The one says to the other " hey, how come we do all the work and he gets all the money?" pointing to the supervisor.

The other says, "I don't know, go ask him."

So Guido goes up to the supervisor and says "Hey, how come we do all the work and you get all a da money?"

The supervisor says "Intelligence".

Guido says "what is this intelligence?"

The supervisor puts his hand on a tree and says "Hit my hand as hard as you can!"

Guido winds up and with all his might tries to hit the supervisors hand. Just as he almost does the supervisor pulls his hand away and Guido hits the tree!

The supervisor says "That's intelligence".

Still smarting Guido goes back to his co-worker and his co-worker says "Hey, what did he say?" With a sheepish look on his face Guido puts his hand on his face and says "hit my hand as hard as you can..."