Get ahead, get a hat

One of many things not to be surprised about when snow cover's thin (though it's now dumping down in the Dolomites and a few other corners of Europe - yay!) is the high accident rate. There's an increased chance not just of holes in your soles, from rocks, but in your head, from collisions with people failing to cope with sketchy hardpack.
So, wear a helmet. Unless of course there's a chance that any potential benefit is outweighed by some of the negative effects of wearing one. In which case, don't wear a helmet. But do ski more carefully.
And if you think risk compensation is phooey, then why, in the event of being hit from behind on piste, is it disproportionately probable, apparently, that the guilty party will be wearing a helmet?
A slightly different effect was recorded on the streets in the UK, where a scientist found cars passed him on his bicycle more closely when he wore a helmet than when he didn't (something a few urban riders were already familiar with). But not many of us have taken the next step, of wearing a long flowing wig to look like a dizzy blonde. He tried that too and got an even wider berth though he did presumably get his backside pinched more at traffic lights.
So there you have it: a theory for why some Scotsmen ski in kilts - they are in fact cross-dressing for safety.