The Ideological Turing Test is an exercise about pretending to hold an opposing ideology convincingly enough that outside observers can't reliably distinguish you from a true believer.
It was first described by economist Bryan Caplan:
Put me and five random liberal social science Ph.D.s in a chat room. Let liberal readers ask questions for an hour, then vote on who isn't really a liberal. Then put [economist Paul] Krugman and five random libertarian social science Ph.D.s in a chat room. Let libertarian readers ask questions for an hour, then vote on who isn't really a libertarian. Simple as that.
Passing the ideological Turing test is a sign that you understand the opposing ideology on a deep level.
The ideological Turing test has a similar motivation to Steelmanning, but works in a different way.
The name comes from the Turing Test proposed by computer scientist Alan Turing, where a computer program must pretend to be a human while human judges try to tell it apart from real humans.
The Ideological Turing Test is an exercise where you try to pretend to hold an opposing ideology convincingly enough that outside observers can't reliably distinguish you from a true believer.