Someone put a comment that do traditional medicines have some medicine to control stupidity. Brain function may be governed by various signaling molecules . I am no expert of medicine but what produces stupid behavior and how it can be cured using traditional medicine could be matter of interest. Ipomea growing on the sides of railway tracks also known as railway creeper if consumed by cows , produced strange behavior. Datura metal fruits and seeds if consumed cause hallucinations. All kinds of "drugs" obtained mainly from Cannabis and Poppy produce stupid behaviour. In one poets saying "Kanak kanak te sau guna madakta adhikay , ya khaye boray jag va paye bauray". Datura and gold both produce insanity , datura by eating and gold by mere possession. Major cause of stupidity could be richness also. Enough wealth creates lot of desires. Unfulfilled desires lead to anger, Anger blurs the vision of man and man with blurred vision leads to stupidity. Renunciation could be one way to check the stupidity. Drugs are more popular among rich and neo rich boys and girls worldwide. Alcoholism is another door leading to stupidity. Pride is another path to stupidity. One mans behavior as stupid has many reasons and many cures. Depending on geographical location, value system, political stability and society structure the values keep on changing. What can be stupid behavior in one part of the globe is considered normal behavior. Criminals also have their way to justify their stupid behavior The medicine lies in yoga. Union with God. It is practiced in differrent ways depending on the age and mental status of the man . Peace of mind is first condition to check the stupid behavior of man. Taking simple food , vegetarian food avoiding alcohol and abstention have been recommended in olden scriptures. But to find a general remedy to control stupidity worldwide is matter of research and if you find one it could lead to world peace also. Perhaps nature has the answer.