From Quartz, by Corinne Purtill, The Five Universal Laws of Human Stupidity
Professor Carlo M. Cipola enunciated these laws, and they are both clearly understandable and profoundly disturbing.
1. We always underestimate how many stupid people there are.
2. Stupidity is independent of every other characteristic. Plenty of well-educated stupid people out there.
3. Stupid people cause loss to others with no gain to themselves.
[there’s a chart for this]
4. Non-stupid people always underestimate the damage stupid people will do.
5. A stupid person is the most dangerous type of person.
He concludes that the only thing that can keep a society from collapsing under the weight of stupid is the extra effort put out by intelligent people. When intelligent people act helpless, or turn solely to their own profit at other’s expense [“bandits”], society goes to hell in a handbasket.
The original essay is also well worth the read.