Sociologist Robert K. Merton coined the term "unintended consequences" (amongst numerous others), and developed an existing notion of manifest vs. latent functions and dysfunctions.
In particular, Merton notes:
Discovery of latent functions represents significant increments in sociological knowledge .... It is precisely the latent functions of a practice or belief which are not common knowledge, for these are unintended and generally unrecognized social and psychological consequences.
Robert K. Merton, "Manifest and Latent Functions", in Wesley Longhofer, Daniel Winchester (eds) Social Theory Re-Wired, Routledge (2016).
In particular, Merton notes:
Discovery of latent functions represents significant increments in sociological knowledge .... It is precisely the latent functions of a practice or belief which are not common knowledge, for these are unintended and generally unrecognized social and psychological consequences.
Robert K. Merton, "Manifest and Latent Functions", in Wesley Longhofer, Daniel Winchester (eds) Social Theory Re-Wired, Routledge (2016).
<https://www.worldcat.org/title/social-theory-re-wired-new-co...>
More on Merton:
<https://en.wikipedia.org/wiki/Robert_K._Merton#Unanticipated...>
Unintended consequences:
<https://en.wikipedia.org/wiki/Unintended_consequences#Robert...>
Manifest and latent functions:
<https://en.wikipedia.org/wiki/Manifest_and_latent_functions_...>