>> i saw that and it's similar to alcohol. we're not allowed to drink until we're 21. we're not allowed to smoke until we're 21. if you wait, i don't see the problem. >> i would definitely agree with teenagers, definitely, but in a culture of situation in which it's 4/20 friendly and education, if they don't need to smoke marijuana until well after high school. >> that is false. it's a skewed study to begin with. i looked into that study and it's not true. it causes new brain cells to grow as opposed to what your study suggests. >> i wouldn't be surprised. there is a lot of developmental changes that happen through adolescence and puberty, as you age, so does the brain. >> all right. pretty unbelievable. that is not the only study that should make people nervous. a separate survey, they say marijuana use increases heart