According to Tobacyk & Milford (1988), the Forer effect (or Barnum effect) is to the tendency to accept generic personal feedback, even if it consists of trivial, general and vague statements, as being highly accurate as if the information has been written specifically for this person. This form of cognitive bias leads us to believe in a large sum of pseudoscientific practices like astrology, palm ready, fortune-telling, and more. Typically, these practices generate widely applicable personality and circumstantial descriptions. This bias relates to subjective validation, the seeking of a relationship of two unrelated events. This causes us to want to believe that this randomly generated statement truly applies to us.
In 1989, Bertram R. Forer published a study on the fallacy of personal validation in which he successfully made his 39 students believe that randomly generated personal profiles (mostly taken from astronomy books) were written just for them.