Apophenia
Apophenia is the spontaneous perception of connections and
meaningfulness of unrelated phenomena. The term was coined by K. Conrad in 1958 (Brugger). […] According to Brugger, “The propensity to see connections between seemingly unrelated objects or ideas most closely links psychosis to creativity … apophenia and creativity may even be seen as two sides of the same coin.” –The Skeptic’s Dictionary
Fiction is the art of apophenia, especially fanfiction when it makes meaningful connections the original producers neither saw nor dreamt of. The habit isn’t restricted to slash, either - non-canonical or semi-canonical pairings of all sorts arise from the fan’s spontaneous perception. Putting together a plot means making connections that don’t tend to hold in reality - from little actions that fit the theme to it all coming together on the last page.
Some people don’t restrict their apophenia to fiction - Immanuel Velikovsky made bad science out of what would have been a marvelous sci-fi premise in Worlds in Collision. Related phenomena listed in the Dictionary include Jung’s notion of synchronicity or “meaningful coincidences,” which seem to result from ESP or a sort of low-grade miracle, and pareidolia, the bad habit of seeing faces in potato chips and the Cydonia region of Mars.
I found the Skeptic’s Dictionary while looking up something else entirely, but the pseudoscience was interesting enough to keep me reading through many entries. I found that when the Skeptic was arguing against independent, falsifiable scientific data (as in I.Q. and Race or the Bible Code), he beat around the bush without ever disproving anything. Even in cases where his arguments sounded good (multiple personality disorder and the related hypnotism), a little more data would have been nice.
He chalks up the MBTI to the Forer effect (also known as the Barnum effect), the same force that makes your astrological sign seem to predict your personality. That’s from the typee’s end, though - the assessor might still be making a psychometric survey yielding a statistical correlation with people’s skills or career choices. An article linked on the page claims otherwise - Measuring the MBTI and Coming Up Short by David J. Pittenger, in the Journal of Career Planning & Placement Fall 1993. Pittenger cites evidence that S/N and J/P are correlated with one another, though he doesn’t say how.
Although the Skeptic attributes the power of the Forer effect to wishful thinking, it sounds like more apophenia to me. Conspiracy theories would also be a kind of apophenia - the persistent belief that the world is more ordered than it, in fact, is.