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.