Say it isn’t so

Blogging on Peer-Reviewed Research

The NYT reports on a this article by Tomas Grim of the Dept of Zoology at Palacky Univ purporting to show a negative effect on numbers of scientific publications for scientists correlated with increasing beer consumption.

According to the study, published in February in Oikos, a highly respected scientific journal, the more beer a scientist drinks, the less likely the scientist is to publish a paper or to have a paper cited by another researcher, a measure of a paper’s quality and importance.

The results were not, however, a matter of a few scientists having had too many brews to be able to stumble back to the lab. Publication did not simply drop off among the heaviest drinkers. Instead, scientific performance steadily declined with increasing beer consumption across the board, from scientists who primly sip at two or three beers over a year to the sort who average knocking back more than two a day.

However, looking at the paper I’m somewhat confused, and not just from the willingness to generalize to all scientists from a single country’s avian ecologists. For one, the scales have to be a goof. Check out the first figure.

Who drinks 2 liters of beer a year? That’s basically teetotalling. Even 6 liters a year (the high end of his effect) would be a very small amount. Is this just alcohol in the beer? At 18ml/12oz beer that would mean each liter corresponds to ~50 beers. At 6 liters that’s still only 300 beers or less than one a day. If instead the author means 2-6 liters/day/person/year that may make more sense. But 6 liters of alcohol a day? Maybe the Czech’s are worthy rivals for beer drinking but that’s now an unbelievably high amount for a non-hobo. How about 100-600 liters of beer a year? One liter is roughly 3 x 12oz beers. That would be a minimum of about 1 beers a day for the left side of the scale (although that starts at 2 so really about 1-2 beers a day is the lowest group), versus people who have about 5-6 beers a day.

I’m having difficulties understanding the quantities of alcohol we’re talking about here. Can anyone enlighten me? If, as the NYT article suggests, the mid range was with 2 beers a day (which would fit with my 100L scaling above), I have even more trouble believing this silly hypothesis that the depressive effects of moderate alcohol negatively impact scientific work. After all the data is pretty level with a +/- bounce of 0.5 from 2-4 liters, or approximately 1-4 beers a day. Then there is a group of 5-6 beer/day drinkers who yank the line down giving it a pretty poor r-square value. I think this is a confusing paper with inadequate data and an improper line fit. At 5 or more beers a day you’re talking about pretty heavy use (not that I haven’t thrown back more than 5 in a day but not every day). Isn’t this really a study showing that alcoholic avian ecologists don’t publish as much as non-alcoholic avian ecologists?

Tomáš Grim (2008)
A possible role of social activity to explain differences in publication output among ecologists