&gt; In the study, researchers looked at the lifestyles and personality traits of 700 Spanish psychology students from two universities. The subjects ranged in age from 18 to 32 and included slightly more women than men.<p>This is a big deal - college students are not a representative sample of the general population when it comes to behavior. There are going to be confounding factors galore here; I can only hope the researchers took care to untangle them.