It takes one to know one is an idiom that originated in the United States. We will examine the meaning of the common saying it takes one to know one, where it came from, and some examples of its idiomatic usage in sentences.
It takes one to know one is a remark one makes when criticized by someone who has similar failings. Often, it takes one to know one is used as a defense against a vague insult. For instance, if your neighbor says that you are an idiot, you may reply it takes one to know one. Occasionally, it takes one to know one is used as a reply to a compliment. For instance, if your neighbor says that your are a genius, you may reply it takes one to know one. Generally, the expression it takes one to know one is considered a juvenile retort; it is mostly used by children. The phrase came into use in the 1920s in the United States, though its specific origin is unknown.
Examples
Russian President Vladimir Putin shot back after US President Joe Biden described him as a “killer”, saying that “it takes one to know one.” (Times of India)
“The fact that he thought of that on that prompt shows this young man not only knows his history but also recognizes difference-makers, and it takes one to know one,” his dad, Jay Suire, said in an interview with his son. (Daily Advertiser)
Morrison responded like a child putting his fingers in his ears, going “lalalala” then saying something along the lines of “it takes one to know one”. (Canberra Times)