‘Scare quotes’

Charles Moore's Spectator's Notes for 14 May.

He's writing about vol 2 of Harold Macmillan's diaries.

"Like many highly educated people, Macmillan used ‘scare quotes’ (there — I am using them myself) to an astonishing degree. Such inverted commas are a device for distancing oneself from something ...."

I've often wondered what they were called. Why 'scared'?

My father described their use thus:

"I'm using this word. It's not the right one but I can't be bothered to think of the one I should be using."