I'm always on the lookout for a new behavioural phenomenon. You know, the sort of curious human behaviour that is almost universal in frequency so that everyone can relate to it, and is yet so simple that it seems to make counter-intuitive common sense. This would include phenomena such as:
+ why right-handed people are slower to solve a rubik's cube puzzle than lefties;
+ why introverts are not as good as extraverts at slicing cakes into an odd number of pieces;
+ why those of us who find driving a car difficult actually have fewer crashes.

In fact, one of those phenomena was made up by me just now, but the other two are true. You see, the other satisfying thing about such simple explanations of the human condition is their simplistic plausibility - they are often so simple that we want them to be true, so we are happy to afford them extra credibility.

Now, I'm not saying I have an explanation for this one, because I think it might belong in the hands of the economists, ergonomists or mathematicians even. All I can give you is a series of observations of behaviour, with a loose psychological interpretation of what might be going on. Which may be correct, or not. I think I have discovered, the Mega-Queue . . .