Grades and Booze and Graphs -- Gee Whiz

October 21, 2008
Posted by Jay Livingston

Drinking lowers your GPA. So do smoking, spending time on the computer, and probably other forms of moral dissolution. That’s the conclusion of a survey of 10,000 students in Minnesota.

Inside Higher Ed reported it, as did the Minnesota press with titles like “Bad Habits = Bad Grades.” Chris Uggen reprints graphs of some of the “more dramatic results” (that’s the report’s phrase, not Chris’s). Here’s a graph of the effects of the demon rum.

Pretty impressive . . . if you don’t look too closely. But note: the range of the y-axis is from 3.0 to 3.5.

I’ve blogged before about “gee whiz” graphs , and I guess I’ll keep doing so as long as people keep using them. Here are the same numbers, but the graph below scales them on the traditional GPA scale of 0 to 4.0.

The difference is real – the teetotalers have a B+ average, heaviest drinkers a B. But is it dramatic?

I also would like finer distinctions in the independent variable, but maybe that’s because my glass of wine with dinner each night, six or seven a week, puts me in the top category with the big boozers. I suspect that the big differences are not between the one-drink-a-day students and the teetotalers but between the really heavy drinkers – the ones who have six drinks or more in a sitting, not in a week– and everyone else.


kristina b said...

I agree. But isn't there already research out there on "binge" drinking and its effect on grades? I don't have time to obsessively google that right now, but I do believe I've heard of it somewhere.

Jay Livingston said...

I didn't Google it either. But I just now took a quick look, and there is indeed a correlation, but I didn't dig into the articles to see how large the effect was. Besides, there's the question of causality. Yes, you'll probably do better on the final if you show up sober instead of sloshed. But if binge drinkers are party animals who don't really care much about learning, will reducing their intake improve their GPA?