Why are legal documents so often written in convoluted and incomprehensible language that the general public and even lawyers, sometimes, can’t understand? Recent cognitive science research tries to answer this question.
Previous studies demonstrated that legal documents appear to be an exception to the communicative efficiency theory of cognitive linguistics. The communicative efficiency theory posits that language develops to be more efficient and concise to save time and ease communication burdens. Legal documents are generally linguistically less efficient and concise and impose greater cognitive processing and memory demands on the reader.
Researchers identified overuse of center-embedded clauses as a feature of legal texts that makes them more cognitively taxing to process by lay readers and even by legal professionals. Center-embedded clauses are clauses inserted within the center of a clause rather than inserted on the edges of the clause or as a separate sentence. In sentences with center-embedded clauses, the subject and main verb phrases are often separated by excessive clausal material which makes them difficult to cognitively process. For example, the first paragraph of a Massachusetts drunk driving law (Massachusetts General Laws c.90 § 24(1)(a)) has over 100 words of clausal material separating the subject and main verb phrase.