As more states legalize medical marijuana and debate recreational use, the scientific community is investigating the plant’s effects on the body and brain. One of the more contentious debates is whether weed is a gateway to hard drugs—a theory that could be negated by expanding marijuana legalization.

While there is no conclusive proof that marijuana use predicts hard drug use, there is a correlation: 61.8 percent of hard drug users start with softer drugs like marijuana, according to the 2010 National Survey on Drug Use and Health.

Although weed might not directly lead users to experiment with hard drugs like heroin, it does act as a portal into the larger drug culture.

The stereotype that marijuana use leads to drug addiction could be debunked if it were legalized for recreational use, distinguishing it from other psychoactive drugs. Because marijuana is generally illegal, users are forced to buy it under the table.

Dealers often peddle harder drugs, exposing stoners to a realm of easily accessible dangerous narcotics. Marijuana is not available commercially, except in Colorado and Washington, but if it were offered in medical dispensaries or retail stores, pot smokers would not be exposed to hard drugs as often.

Most Americans—58 percent—are in favor of legalization, according to an Oct. 22, 2013 Gallup poll. Not to mention the 42.8 percent of Americans older than 12 who admitted to using pot at least once, with 12.1 percent partaking in the last year, according to the 2012 National Survey on Drug Abuse and Health.

Because marijuana is so popular, it only makes sense for the federal government to oversee its production and safe sale instead of leaving distribution in the hands of drug traffickers who certainly are not held to the standards of the Federal Drug Administration.

The gateway argument pertains not simply to access to drugs but to dependency itself. About 9 percent of users become addicted, according to information from the National Institute for Drug Abuse. While 9 percent is a significant sampling, it is just as significant to note that 91 percent of users do not become hooked.

Psychological dependence varies from person to person, but that does not directly lead to a desire to try harder drugs that in some cases lead to addiction.

The most widely accepted definition of addiction is vague—the Diagnostic Statistical Manual of Mental Disorders defines addiction as “the continual use of a substance despite its negative consequences,” and studies on marijuana’s addictive qualities are influenced by the medical professional definition of addiction.

Some studies of marijuana dependency support the addiction theory, but that does not mean every person will go through the physical withdrawal symptoms if he or she stops toking.

Many people only use marijuana and never partake of drugs such as cocaine or heroin. While marijuana use is not responsible for hard drug use in many instances, the connection still exists because of marijuana’s ready availability and proximity to other black market drugs. When a person first tries a drug, it can open a mental door to the idea of using another drug. But the increased likelihood for temptation does not apply to everyone, in the same way that riding a bike does not make you more likely to join a motorcycle gang. It may be a circumstance that usually comes first, but it does not directly precipitate further drug use later in life. To assume so is alarmist and unfounded.

Developing policies based on uncertain science and urban myth can create fear and bias, as in the case of people who claim weed is a gateway drug and advocate to ban it completely. To make the most balanced decision about drug consumption, the average marijuana user in the U.S. needs to be better informed about the scientific and social findings about the drug before deciding marijuana is a conduit to more dangerous substance use and abuse.