The headline last week promised exciting news: “Geniuses ‘less prone to hangovers’.” Could it be that the same brain chemistry responsible for intelligence also mitigates the effects of heavy drinking?

Alas, no, or at least not from this study. There was no scientific experiment, just a survey asking about people’s drinking habits. Although “a higher IQ score was associated with a lower prevalence of hangovers”, the researchers suggest that more intelligent people “respond better to advice not to binge drink.” Who would have thought it?

Such blindingly obvious results are reported as news because ethical concerns prevent researchers from doing proper research on human subjects – force-feeding people alcohol in the interests of science is clearly problematic.

So researchers just conduct surveys instead. But surveys are generally unable to distinguish causation from simple correlation, not that this stops the media from happily publishing the absurd “news”. There were two prime examples just last month. One claimed that listening to explicit music made people more likely to have sex; another said that watching wrestling leads teenagers to fight more with their dates. Neither correlation is surprising, but neither is evidence in itself for a causal link.

Then yesterday up pops another one: a Reason Foundation study reported on an Age blog, showing that those who drink in moderation earn higher incomes than those who don’t drink at all, particularly if they drink socially. The researchers hypothesise that this might be due to the positive social capital effects of networking over a few drinks. It might. But did it not occur to them that people who earn more can also afford to drink more, and to do so in bars rather than at home?

If you don’t ask tricky questions, it’s much easier to get the answers you’re looking for.