It’s hard to get a handle on stupid, and what it actually is. Fortunately, an economics history professor outlined the affliction way back in 1976. The problem is most of us weren’t listening.

Via QUARTZ:

Stupid people, Carlo M. Cipolla explained, share several identifying traits: they are abundant, they are irrational, and they cause problems for others without apparent benefit to themselves, thereby lowering society’s total well-being. There are no defenses against stupidity, argued the Italian-born professor, who died in 2000. The only way a society can avoid being crushed by the burden of its idiots is if the non-stupid work even harder to offset the losses of their stupid brethren.

The UC Berkeley professor developed five universal laws of stupidity. Important for those of us who’ve been trying to put our finger on what, exactly, makes a stupid person stupid have the The Third (and Golden) Law:

A stupid person is a person who causes losses to another person or to a group of persons while himself deriving no gain and even possibly incurring losses.

Read more at QUARTZ, or learn more about Cipolla and his work.