I can only assume most of you didnt read the article.

Nowhere did it say that smoking weed will cause you to move on to heroin. All it does is briefly describe the gateway drug arguments. And even then, the scientists dont show which side they are on.
The idea that smoking cannabis increases the user's chance of going on to take harder drugs such as heroin is highly contentious. Some dub cannabis a ??gateway? drug, arguing that peer pressure and exposure to drug dealers will tempt users to escalate their drug use. Others insist that smoking cannabis is unrelated to further drug use.
All it says is that, if you smoke cannabis and then go on to take heroin, you will need more than usual to get your "fix".

However, personally, i dont think that it provides "overwhelming evidence that nobody in the brain??s developmental stage ?? under the age of 21 ?? should use cannabis". Just that if you do plan on taking heroin later in life, you might want to steer clear of cannabis.
ubermoose Reviewed by ubermoose on . DONT SMOKE WEED KIDS, A NEW STUDY SHOWS PROOF OF A NEW PROBLEM "Adolescents' use of marijuana may increase the risk of heroin addiction later in life", as a new study sprinkles retardedness up your nose without asking you first Why teenagers should steer clear of cannabis - drugs-alcohol - 05 July 2006 - New Scientist Rating: 5