Who coined the term elephant in the room?
The expression is American in origin, though it has become extremely common in the UK since 2004. In the article you mention, Marcel Berlins called it "the phrase I most hate in the whole world", because it has become such a cliché. Before 2004 it only turned up in text written in or referring to the US. The American phrase is usually the elephant in the living room but British writers have shortend it slightly by leaving out the penultimate word. It refers to some a problem or controversial issue that's obviously present but which everyone ignores or avoids mentioning, usually because it's politically or socially embarrassing. Marcel Berlins commented that he had traced the expression to a 1989 BBC television film whose director had said he had taken it from the Belfast writer Bernard MacLaverty. The latter had described the situation in Northern Ireland as like "having an elephant in your living room", though with the sense of something difficult in your life that you got accustomed to and tried your best to ignore, as people in Northern Ireland did with the Troubles. Marcel Berlins said that MacLaverty had used the idea in a children's story of 1978, A Man in Search of a Pet. The Oxford English Dictionary added an entry for the expression to its online service in June 2006. It doesn't mention MacLaverty and instead argues it's originally American. The first example it has in our current sense is the title of a well-known American book of 1984 by Marion H Typpo and Jill M Hastings, An Elephant in the Living Room: a leader's guide for helping children of alcoholics. There are earlier examples. A piece in the Winnipeg Free Press in October 1976 said, "What is big and unfamiliar is mistrusted. Anyone would feel uncomfortable with an elephant in the living room, no matter how friendly it might be." The OED's entry also notes an example from the New York Times of June 1959: "Financing schools has become a problem about equal to having an elephant in the living room. It's so big you just can't ignore it." Neither of these are in our current sense but are obviously its precursors. The idea seems to have been around for quite some time before it became common or took on its modern sense, most probably being reinvented from time to time by writers seeking a vigorous image. Bernard MacLaverty's claim to priority is looking rather shaky, since the expression was known in the US before he wrote his book.