Students were given personnality summaries and were asked to rate their accuracy. desite the summaries being identical, they rated them as highly accurate average.
We often believe vague statements about personnalities are highly specific to just ourselves
See the full study here :
Forer, B. R. (1949). The fallacy of personal validation: a classroom demonstration of gullibility. The Journal of Abnormal and Social Psychology, 44(1), 118, https://doi.org/10.1037/h0059240