it takes one to know one


Also found in: Acronyms.

(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

it takes one to know one

The person who expressed criticism has similar faults to the person being criticized. This classic retort to an insult dates from the early 1900s. For example, You say she's a terrible cook? It takes one to know one! For a synonym, see pot calling the kettle black. A near equivalent is the proverbial it takes a thief to catch a thief, meaning "no one is better at finding a wrongdoer than another wrongdoer." First recorded in 1665, it remains current.
See also: know, one, take

it ˌtakes one to ˈknow one

(informal, disapproving) you are the same kind of person as the person you are criticizing: ‘Your brother is a real idiot.’ ‘Well, it takes one to know one.’
See also: know, one, take