Hey Joe and Jane College, want better grades? Live cleaner and healthier lives. A new study at the University of Minnesota shows that unhealthy patterns of behavior — smoking, drinking, gambling, camping out on the Internet, and so on — clearly correlate with low grade point average. The study also showed that working a job, even a full-time one, does not negatively impact academic performance. Of course, Joe and Jane, your parents could have told you all of this. And probably did.