Lectio brevior is one of the key principles in textual criticism

Textual criticism

Textual criticism is a branch of literary criticism that is concerned with the identification and removal of transcription errors in the texts of manuscripts...

, especially biblical textual criticism. The principle is based on the widely accepted view that scribes showed more tendency to embellish and harmonise by additions and inclusions than by deletions. Hence, when comparing two or more manuscripts of the same text, the shorter readings are more likely to be closer to the original.