Tuesday, 30 March 2010

Hangovers impair perceived performance but not performance

Take a couple hundred students. Make them sit through a lecture. Then, give half of them non-alcoholic beer, the other half, full strength. Measure blood alcohol of both groups. Put them to bed. Next morning, make them all do two tests: part of the GRE, and a quiz on the prior day's lecture.

Then, do it again, but flip the groups so you can get within-subject measures.

You might expect that the hung-over students would perform worse on the tests. In surveys after the tests, those in the alcohol treatment certainly thought they'd done worse. But, there was no difference between the two groups' performance. The students thought that alcohol had impaired their performance, but there was no difference between the two.
While our findings are discordant with results of survey studies that find associations between alcohol use and academic problems, these studies are potentially confounded in that a third factor (e.g. personality) may cause both excessive drinking and academic difficulties and causal order is unknown (i.e. academic difficulties could lead to excessive drinking). Our findings are consistent, however, with a study on the effects of intoxication on next-day occupational performance [33]. In that study, merchant marine cadets’ performance on a diesel engine simulator was not affected significantly, relative to placebo, on the morning after intoxication (mean BrAC.115 g%), but self-rated performance was significantly worse. Similarly, another laboratory study found measures of combined attention and reaction-time to be the only neurocognitive measures affected on the morning after 0.11 g% BrAC [74]. [emphasis added]
The Boston University story on the study is here; the full paper is here.

Now, what does this mean for WHO-approved survey measures of problem drinking that ask respondents how often their drinking kept them from doing what was normally expected of them? Might mean a bit of upward bias in responses there, mightn't it?


  1. Exactly how many beers did they drink to get hungover?

    My bet is the pussy researchers figured just two beers would do 'em (but I haven't paid to download the orginal research, so I don't know).

    In any case, just to make really, doubly sure of the results, could you not replicate the research again with a bottle or four of whiskey?

    If so, I'd be happy to volunteer as a research subject. :-)

  2. It does sound nice, but doing the paperwork to get it through the human ethics committee just isn't worth it. Doing the paperwork to get damn near anything through HEC just isn't worth it.

  3. Paper says the guys were getting around 7 standard drinks each.

    I'll also stick my name down for any experiment replication. A fair few UC's honours students say they wouldn't mind volunteering either. Just a thought, Eric :-).

  4. It's encouraging to have an honours cohort that seems keen on the prospect of free booze! In other years, food and beer have been left at the end of some functions - very disappointing.

  5. @James: You're not going to get drunk on 7 standard drinks, are you.

    Not unless you're drinking Steinlager. Or (being Boston) Rolling Rock.

  6. @Eric: "In other years, food and beer have been left at the end of some functions..."

    That's disgraceful. What sort of students do you have down there!

  7. Well, 7 drinks counts as binge drinking according to the usual sorts....

    In fairness to the students, while the food was typically excellent, the beer was not.

  8. "In fairness to the students, while the food was typically excellent, the beer was not."

    Quality of the beer should not matter to honours students. When I was that age I used to think Tui was a premium drop ...

  9. @PC: Agreed: http://esprit-de-l-escalier.blogspot.com/2010/03/you-call-that-hang-over-this-is-hang.html.

    @Matt: A few scholarships and student loans means that my Tui days are well behind me. Cider is more my thing these days.