smoking anything forgets up the lungs.
maybe if you smoked pot and and cigarrettes, then there would be no bad things that wouldnt already be happening to you.
now that i think of it however, there is also a lack of motivation, laziness, and a few other things that my health teacher told me. and my dad (Medical School graduate, has worked in ER, Family Practice, and currently Urgent Care) says that people get to a hilarious level of caution, which makes them stop like 40 or 50 feet away from the car in front of them on the freeway, which can sometimes result in an accident.
so as explanation to your SAT thing, the people were probably already incredibly motivated in order to take that risk. i also want to know if they were a constant user before or if they started when the experiment started.
we need details on this, cause some of us never watched that show.