A philosophical theory based upon the circumstances where one’s conscious thoughts, perceptions, and/or beliefs come to fruition beyond the feeling of reasonable coincidence.

The eponymous theory can be somewhat compared to frequency illusion, (also known as the Baader Meinhof Phenomenon), and has some aspects of manifestation, but is not directly similar to either.
an example of the calder effect:

*talking with my dad about the fish in my room*
me: that things gotta die soon
dad: it’s been alive for 5 years and has surpassed his other 3 friends life expectancies.
*2 days later*
*fish dies*

boom . ~calder effect~
by cxlderr July 12, 2021