Let's see if we can explain robbery and a protection racket from a Darwinian perspective.
Amongst prehumans one individual might observe that another had been successful in its food gathering and simply helped himself.
Finding this easier than going out and gathering his own food this robbery became a habit. But other proto humans felt territorial about their food and fought back until it was realized that the food thief only took a small portion of his victims stores of food and thus would go away if given a small portion of the accumulated food.
And so was born the “Monkey Mafia” by Capice-un monkeys.