Is there a term for thinking anything heard from an outside source about yourself or someone else is true?

Question

This is most prominently seen with people who follow astrological signs. E.g. "Well Cancers are very sentimental people, so that totally explains me/my mom/my friend". Is there a phrase or specific term for this fallacy of seeing something said about yourself by an outside source and immediately thinking "Oh, that's definitely me", even though it could apply to most people in some way? Another example could be taking a poorly designed personality test, yet still agreeing with all the results. These are most often general, blanket statements, but they don't have to be.

I'm referring to the terminology of this (usually subconscious) thought process rather than the type of person who might do it.

Answer 1

It's called the Barnum effect or Forer effect.

The Barnum effect, also called the Forer effect, is a common psychological phenomenon whereby individuals give high accuracy ratings to descriptions of their personality that supposedly are tailored specifically to them, that are in fact vague and general enough to apply to a wide range of people.1 This effect can provide a partial explanation for the widespread acceptance of some paranormal beliefs and practices, such as astrology, fortune telling, aura reading, and some types of personality tests.

Answer 2

They are "personalizing" general or vague statements. They are applying general or vague human qualities to themselves or to others specifically.

https://www.thefreedictionary.com/personalize

Answer 3

Labeling people gratuitously, or bestowing unwarranted qualities on them, based on their Zodiac sign, is a practice favored by the mediocre.