drugs like Heroin, Cocaine, Marijuana, DMT, Morphine, LSD etc.
(Remember , alcohol is a foreign substance for human body and its not required by it – thats what medical science says, so alcohol is like cocaine, heroine etc.)
It is known that some large groups of people have become addicts to alcohol who have had a long ancestry to alcoholism. Their offspring are easily sucked into the alcohol dependency. And those who havn’t , can easily resist the habit.
So if large population of humans start consuming illegal drugs which modify behavior , attitude, morality and common sense , then what kind of human beings are expected to be born. Probably tolerant strains or those who cannot live without drugs right from infancy like a child needing milk?