Horror aequi,[a] or avoidance of identity,[2]: 100 is a linguistic principle that language users have psychological[3]: 266 or physiological[1]: 51 motives or limits on cognitive planning[1]: 51 to avoid repetition of identical linguistic structures.
[4]: 219 One of the most widely cited definitions[6]: 39 [7]: 71 is that of Günter Rohdenburg: "the horror aequi principle involves the widespread (and presumably universal) tendency to avoid the use of formally (near-)identical and (near-)adjacent (non-coordinate) grammatical elements or structures.
The term horror aequi is sometimes extended to the stylistic preference to avoid repeating the same word in a given text.
[citation needed] Other examples clearly demonstrate how horror aequi helps prevent confusion.
Merely adding semantic difference can add some clarity:[2]: 101 The horror aequi principle holds that both of these examples would be avoided.