3. Marijuana is a "gateway" drug

-- it leads to hard drugs
This is one of the more persistent myths.
A real world example of what happens when marijuana is
readily available can be found in Holland. The Dutch partially
legalized marijuana in the 1970s. Since then, hard
drug use -- heroin and cocaine -- have DECLINED substantially.
If marijuana really were a gateway drug, one would have
expected use of hard drugs to have gone up, not down. This
apparent "negative gateway" effect has
also been observed in the United States. Studies done in the
early 1970s showed a negative correlation between
use of marijuana and use of alcohol. A 1993 Rand Corporation
study that compared drug use in states that had decriminalized
marijuana versus those that had not, found that where
marijuana was more available -- the states that had
decriminalized -- hard drug abuse as measured by emergency
room episodes decreased. In short, what science and
actual experience tell us is that marijuana tends to
substitute for the much more dangerous hard drugs like alcohol,
cocaine, and heroin.