Carlo M. Cipolla, Italian economics historian, wrote a tongue-in-cheek book about stupidity (The Basic Laws of Human Stupidity, il Mulino, 2011). It is a concise and informative view on the choices stupid people make, where to find them, and what to do about them. This is a summary of what he said:
Law 1. Always and inevitably everyone underestimates the number of stupid individuals in circulation.
Law 2. The probability that a certain person is stupid is independent of any other characteristic of that person.
Stupid people are found everywhere, in equal numbers occupying every socioeconomic class and occupation. There are as many stupid people teaching university as there are in prison. And the number of stupid people in both is surprisingly large.
People are free to help or hurt themselves, and to help or hurt others. The combination chosen puts them in one of four quadrants:
Choices that harm themselves and harm others are the unique purview of the stupid.
Law 3. A stupid person is a person who causes losses to another person or group of persons while himself deriving no gain and even possibly incurring losses.
The amazing thing here is that stupid people do this harm to others and themselves unshakably convinced that they have made the wisest choice. This is the heart of stupidity. It involves a fundamental misreading of reality to form an incorrect worldview, and then prioritizing that worldview over reality. Stupid people become the living embodiment of the Aristotelian philosopher, believing the narrative over all contrary evidence.
Essentially, stupid people are dangerous and damaging because reasonable people find it difficult to imagine and understand unreasonable behavior.
This is a core problem with the interval between 300 B.C and the mid- to late-1600s: Aristotle's philosophy was so persuasive and common (so much that most religions adopted it lock, stock and barrel, Christianity first [Plato in the Nicean creed, 300 A.D.], then Jews and Muslims [1200 A.D.] then Christianity again [Aristotle, 1250 A.D.]) that anyone arguing contrary to Plato and Aristotle was dismissed even when it was obvious that Plato and Aristotle described a different world than the one we had. Getting out of the dark ages was a huge problem for the intelligent, and the one who did it best (Petrus Ramus, 1532) was murdered by an Aristotelian for writing Everything Aristotle Said Was False.
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.
Thus they have power, and are dangerous. They need to be avoided, not fought.
Even when one becomes aware of the attack, one cannot organize a rational defense, because the attack itself lacks any rational structure.
Law 4. Non-stupid people always underestimate the damaging power of stupid individuals. In particular non-stupid people constantly forget that at all times and places and under any circumstances to deal with or associate with stupid people infallibly turns out to be a costly mistake.
Law 5. A stupid person is the most dangerous type of person.
More dangerous than a bandit. Bandits have known damage and can be removed from society. Stupid people can't be stopped.
Avoidance is the only known means of dealing with stupid people.
Education doesn't work, as they have already decided how the world works and a challenge to that worldview is deemed immoral, and thus educators are immoral to the stupid and will be attacked.
Authority doesn't work because when the worldview is challenged by someone in authority, the authority is considered evil and must be attacked to preserve society.
Love tends not to work unless you adopt and hold the stupid worldview, and the risk of challenging it is betrayal and the all-consuming attack that follows.
I've made other posts on how to identify these stupid people:
I am also writing a post about the self-reinforcing nature of stupidity in science.