who said the definition of insanity

The phrase "the definition of insanity is doing the same thing over and over again and expecting different results" is often misattributed to Albert Einstein. However, there is no evidence that he actually said this. The origin of the phrase likely dates back to the early 1980s within 12-step program meetings such as Alcoholics Anonymous and Narcotics Anonymous, and it appeared in print in a 1983 novel by Rita Mae Brown. It became popularly linked to Einstein around 1990, but this attribution is incorrect. The actual definition of insanity refers to a severe mental disorder or madness, which is different from the popular quote's meaning about repeating mistakes.