Legal documents are notoriously difficult to understand, even for trained lawyers. Now, a new study from MIT cognitive scientists sheds light on why these texts are so impenetrable. The research suggests that the convoluted language of “legalese” serves a specific purpose: to convey a sense of authority.
Published this week in the Proceedings of the National Academy of Sciences, the study found that even non-lawyers instinctively use complex language when asked to write laws. This behavior mirrors the use of special rhymes and archaic terms in “magic spells” to signal their power.
Edward Gibson, an MIT professor of brain and cognitive sciences and the study’s senior author, explains: “People seem to understand that there’s an implicit rule that this is how laws should sound, and they write them that way.”
The research team, led by Eric Martinez, PhD ’24, and including Francis Mollica from the University of Melbourne, conducted a series of experiments to uncover the reasons behind legalese’s prevalence.
Unraveling the Complexity of Legal Language
Previous work by Gibson’s team identified a key feature of legal documents: the frequent use of long definitions inserted in the middle of sentences, known as “center-embedding.” This structure, rare in everyday language, significantly increases the difficulty of comprehension.
To test their hypotheses about the origins of legalese, the researchers recruited about 200 non-lawyers through a crowdsourcing platform. Participants were asked to write laws prohibiting various crimes and to craft stories about those crimes.
The results were striking. When writing laws, participants consistently used center-embedded clauses, regardless of whether they wrote the law all at once or in stages. However, when writing stories about the same topics, they used much simpler language.
In a separate experiment, participants were asked to write laws and explanations of those laws for foreign visitors. Again, they used complex structures for the laws but opted for simpler language in their explanations.
These findings challenge the idea that legal documents become complex through a process of gradual editing and addition. Instead, they support what the researchers call the “magic spell hypothesis” – the notion that legal language deliberately adopts a distinctive style to set it apart and convey authority.
Why it matters: This research could have significant implications for efforts to make laws and legal documents more accessible to the public. By identifying specific linguistic features that contribute to the complexity of legal language, the study provides a foundation for developing more comprehensible legal texts without sacrificing their authority or effectiveness.
The study also raises questions about the cultural and historical origins of legal language. Gibson’s team plans to analyze early American and British laws, as well as ancient legal codes like the Hammurabi Code, to trace the evolution of these linguistic patterns.
“We have learned only very recently what it is that makes legal language so complicated, and therefore I am optimistic about being able to change it,” Gibson says. This optimism comes despite decades of largely unsuccessful efforts to simplify legal language, dating back to President Richard Nixon’s 1970s directive to write federal regulations in “layman’s terms.”
As society grapples with increasingly complex legal and regulatory frameworks, the need for clear, understandable legal language has never been greater. This MIT study not only explains why legal documents are so difficult to read but also points the way toward potential solutions. By understanding the psychological and linguistic factors at play, we may be able to develop new approaches to legal writing that balance authority with accessibility.
