During the second GOP debate, Republican presidential candidate Carly Fiorina shared a personal story about the loss of her stepdaughter to drugs. The story came up as a response as candidates were debating the legalization of marijuana. (CNN)

"We are misleading young people when we tell them that marijuana is just like having a beer. It's not." -- Carly Fiorina discussing marijuana at the CNN GOP debate last night.

This statement is 100 percent correct -- but not for the reason Fiorina thinks it is. The point she was trying to make was that marijuana is more dangerous than alcohol. She says that today's marijuana is a lot stronger than the marijuana her generation grew up with, and links marijuana use to addiction to other, far more dangerous drugs, like the ones that cost her stepdaughter her life.

Linking marijuana to more dangerous drugs is a version of the "gateway hypothesis" -- that pot use inevitably leads to experimentation with more dangerous drugs. But the evidence does not support this claim. It's true that many people who use hard drugs like heroin and cocaine have tried marijuana in the past. But the overwhelming majority of people who use marijuana do not go on to try other drugs.

Moreover, marijuana is, in fact, far safer than alcohol. Compared to alcohol drinkers, marijuana users are

A 2010 Lancet study found that marijuana was far less harmful than alcohol at both the individual and societal levels. It's less addictive. Marijuana users are considerably less prone to violence than drinkers.

This is not to say that marijuana is completely safe. Like any other human activity, there are risks associated with smoking pot. The more you smoke, and the younger you start smoking, the greater these risks become. The same can be said for alcohol.

But Fiorina is right that smoking pot isn't like having a beer -- on balance, it's a lot safer.