I agree that the small standard deviation suggests that either that doesn't happen or the people in question are much less prevalent than 10% of the population (a number I picked because I have ten fingers). I also suspect that the mechanism roystgnr identified is stronger than the mechanism I identified.
This study isn't set up to differentiate between people, which is what we would need to make a warning policy.
(I had an erroneous statement about the sample size here, which I've deleted.)
Small n? They used 819 subjects - that's bigger than pretty much any psychology cited on LW!
The latest SMBC made me laugh a bit, so I thought I'd bring extra LessWrong attention to it.
I don't know if pointing out the subject of the comic in advance will make it more or less funny. Knowing that might be more data regarding that recent study claiming that spoilers don't actually spoil stuff...