Essentially stupid people are dangerous and damaging because reasonable people find it difficult to imagine and understand unreasonable behavior. An intelligent person may understand the logic of a bandit. The bandit’s actions follow a pattern of rationality: nasty rationality, if you like, but still rationality. The bandit wants a plus on his account. Since he is not intelligent enough to devise ways of obtaining the plus as well as providing you with a plus, he will produce his plus by causing a minus to appear on your account. All this is bad, but it is rational and if you are rational you can predict it. You can foresee a bandit’s actions, his nasty manoeuvres and ugly aspirations and often can build up your defenses.
With a stupid person all this is absolutely impossible as explained by the Third Basic Law. A stupid creature will harass you for no reason, for no advantage, without any plan or scheme and at the most improbable times and places. You have no rational way of telling if and when and how and why the stupid creature attacks. When confronted with a stupid individual you are completely at his mercy. Because the stupid person’s actions do not conform to the rules of rationality, it follows that:
A) one is generally caught by surprise by the attack; b) even when one becomes aware of the attack, one cannot organize a rational defense, because the attack itself lacks any rational structure.
Cipolla – “Laws of stupidity”