Legal language is often ambiguous. Consider: “Only cars and trucks with permits are allowed.” Does [PP with permits] have “wide scope” over the entire series [NP cars and trucks] or “narrow scope” over only the closest noun, [trucks]? Judges often choose narrow scope, citing a legal canon, the “Last Antecedent Rule.” But they sometimes choose wide scope, referencing the “Series Qualifier Canon,” which assigns modifiers to a series. Though judges claim to want to use “most people’s” interpretations, these conflicting choices led us to ask “What WOULD most people say?” We ran three experiments to find out.

Overall, wide scope was preferred. With biased PPs, the preference dropped slightly when the bias matched the last noun, “[NP cars and trucks] [PP with trailers],” but not the first, “[NP trucks and cars] [PP with trailers],” where a universal syntactic “No Crossing Branches principle” limits the PP’s domain. With temporal PPs, “People may park [NP cars and trucks] [PP on weekends],” the preference was also uniformly wide scope, not surprisingly, since these PPs can only modify verbs, not nouns. Taken together, our experiments show how experimental psycholinguistics can offer powerful evidence about how “most people” understand legal language, important information for judges and lawmakers alike.