Way back, as early as 14th century England, "stone blind" or "stone drunk" meant being as blind or as drunk as you could get. "Stoned"--the state of being very intoxicated by drugs or alcohol--probably grew from that.
But it wasn't until the 1970s that anyone was ever called a "stoner," a term that still means about the same thing: someone whose life revolves around getting high from smoking marijuana.
"Stoner" arrived when marijuana stopped being just a "hippie" thing and came into wider use. Stoners didn't necessarily have any connection to the utopian, peace-loving, communal-living hippie values that had spread the use of pot earlier. But they did have the reputation for being very laid-back that they have today.
Stoners are stereotypically harmless but useless: Not liable to steal anything like a crack user might be expected to do, for example, and not hurting anybody--but not contributing much, either.(Debates continue to rage about how addictive or dangerous pot is, but there is clear evidence of harm to young people who are still developing physically and mentally.)
Lately, popular culture seems to be obsessed with everything associated with the mellow 1970s, including marijuana madness. Now there's even "stoner rock": basically '70s-style music with a modern, experimental twist.
