I thought this was a fascinating aside in Ruha Benjamin’s Race After Technology pg 63. It captures something which the contemporary sense of stereotype as reductive/cliche tends to miss: the fact these categories are impervious to countervailing evidence and reproduce the same judgement in different circumstances:
It first referred to a practice in the printing trade whereby a solid plate called a “stereo” (from the ancient Greek adjective stereos, “firm,” “solid”) was used to make copies. The duplicate was called a “stereotype.” The term evolved; in 1850 it designated an “image perpetuated without change” and in 1922 was taken up in its contemporary iteration, to refer to shorthand attributes and beliefs about different groups. The etymology of this term, which is so prominent in everyday conceptions of racism, urges a more sustained investigation of the interconnections between technical and social systems.