The origin of 'elephant in the room'?

[Ben]

Could this be the root of the phrase 'Elephant in the room'?

James Gleick, in his 1987 book 'Chaos' quotes psychiatrist and dynamicist Arnold Mandell, 'When you reach an equilibrium in Biology you're dead. If I ask you whether your brain is an equilibrium system, all I have to do is ask you not to think of elephants for a few minutes, and you *know* it isn't an equilibrium system.'

There is no room mentioned and here it is 'elephants' not 'elephant' but it seems to me that perhaps people who knew this quote might have found it a convenient reference using the shorthand 'elephant in the room' for a shared, persistant thought.

[Ben]

My friend mrtumnus from twitter and the jonronson.com found this

http://www.worldwidewords.org/qa/qa-ele2.htm

which has a far more convincing account of where the phrase may have come from.