takes one to know one

(it) takes one to know one

A childish retort used to suggest that the person who has accused someone of being some negative thing is in fact that thing (as if being that thing would help one to identify others of like kind). A: "You're a real jerk!" B: "Yeah, well, it takes one to know one!" A: "I don't want to sit next to her—she's a nerd!" B: "Takes one to know one!"
See also: know, one, take
Farlex Dictionary of Idioms.

(It) takes one to know one.

Inf. You are one also. A: You are a stupid oaf. B: So are you. It takes one to know one.
See also: know, one, take
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • (it) takes one to know one
  • it takes one to know one
  • tell me about it
  • the genuine article
  • genuine
  • genuine article
  • far be it for/from me to...
  • far be it from me
  • far be it from me to
  • far be it from one to
References in periodicals archive
IT TAKES ONE TO KNOW ONE: Anfield legends (from top left) John Aldridge, Alan Kennedy, Ian Callaghan, Sammy Lee, Ian Rush and Phil Neal today praised the current crop of Reds stars
Champions of Europe 2005: LEGENDS' TRIBUTE TO NEW KOP KINGS
However, based on the theory it takes one to know one, Wales on Sunday, in this instance, agrees wholeheartedly with Mr Davies' 'expert' opinion.
A day for our heroes, not politicians
. "It Takes One to Know One: Passing and Communities of Common Interest." Critical Inquiry 20 (Summer 1994): 715-36.
"Nothing was Lost in the Masquerade": The Protean Performance of Genre and Identity in Charles Johnson's Oxherding Tale
His nod to the subject of the book comes in his last sentence, "But then, as I hope to have persuaded my fellow, newly constituted spooks, as we begin benignly to stalk a new Europe, it takes one to know one."
Shakespeare in the New Europe
Fair enough, but it apparently takes one to know one: "Hollywood should not be making exploitive violent and exploitive sex films.
View masters
"Takes one to know one," Treddy said as he gave her a hug.
Treddy Treadmore: search for the Loch Ness Monster
Ironically, Arnold commonly warns the clearcutting magnates that environmentalists are driven by a 'cult' kmentality: "Once newly committed people have joined an environmental group, they become True Believers who will fight and die for the cause." I guess it takes one to know one.
Clearcuts, Moonies and right-wing death squads
Everyone would say, "Well, it takes one to know one," and my credibility would vanish.
A star was born
And I say that on the basis that it takes one to know one.
Alfredo's no use to Gers in stand so the old heads in dressing room must talk sense into him; RANGERS IT'S TIME TO WISE UP; (Just like Arthur and Ronald did to yours truly)
It's painfully trite to say it takes one to know one, but in this case it cannot be helped.
To the achieving underachiever
Maybe because "it takes one to know one", or do they realise none has the credentials for the job?
Leave politics as usual aside; Letters
And trust me when I say, it takes one to know one here, and I know one when I see one.
Insanely interesting books
The sources said that Lohan has said that she knows her life is "out of control," but doesn't think the precept, "It takes one to know one," is the way to go.
LiLo rejects Charlie Sheen's 'mentor' offer
Levine, it takes one to know one. After all, he was one of the first employees of Veritas - rising from engineer to executive vice president there before Symantec bought the company in 2004 for $13.5 billion.
Startup decides on Nashua, not Worcester
If it takes one to know one, then Forster couldn't have asked for a more glowing reference than the Italian World Cup–winning legend he has studied throughout the formative years of his career.
It's great to hear Buffon's praise ..he's my hero; SAYS FRASER FORSTER