Stan Twins Theory

In the Gravity Falls fandom, the Stan Twins Theory refers to the fan-theory that the character "Grunkle Stan" has a twin brother. It was a popular theory during the course of the show, and was backed up by background elements in various episodes.

As of the episode "A Tale of Two Stans", this theory was revealed to be true. Grunkle Stan does have a twin brother named Stanford Pines, which is the name Grunkle Stan had been going by for the last thirty years. Grunkle Stan's real name is Stanley Pines.

Significance to Transcendence AU

The Transcendence AU was created shortly before October 5th, 2014. As this was several months before the airing of "A Tale of Two Stans", the true nature of the Pines family was not yet known. The Stan Twins Theory was popular enough, however, that many early authors in the AU took it into account in their writing.

The result is that most works in the AU created both before and after the airing of "A Tale of Two Stans" consider "Grunkle Stan" to have a twin brother. However, most authors assumed that Grunkle Stan's name was actually "Stanford Pines", as he claimed it to be. Thus, in early TAU works, Grunkle Stan's lost twin brother is referred to as "Stanley Pines". This is why the Stanley Pines Memorial Library of the Supernatural is named after Grunkle Stan.

After "A Tale of Two Stans", TAU creators began using the correct names for the twins, but earlier created work was not revised to fix the mistake.