Did Einstein really say the “definition of insanity” quote?

What you need to know

The line “insanity is doing the same thing over and over and expecting different results” is widely credited to Albert Einstein, but researchers have not found it in his writings, speeches, letters or interviews. Einstein died in 1955. Closely related versions appear in recovery literature around 1981, and the familiar wording appeared in Rita Mae Brown’s 1983 novel “Sudden Death.” Reference works on Einstein list the attribution as unsupported. So the clean answer is: useful saying if you like it, but not a verified Einstein quote.