Marijuana doesn’t make the user stupid. When high, one’s thinking isn’t clear, plus it’s very hard to concentrate. But pot doesn’t subtract points from a user’s IQ.
Regular Marijuana use actually lowers the IQ several points and causes a susceptibility to schizophrenia. Remember how people used to say that marijuana made them feel paranoid/ well, it may not have been joke. Paranoia is a type of schizophrenia. Anyway scientists now say that there is a definite connection to violence.