Syntactic variation offers a lens through which we may explore what underlies language structure. For example, what motivates our tendency to displace longer VP-subordinate constituents farther from the verb? (We see this in noting that NP displaced beyond PP seems odd in “We found pp[in Santa Barbara] np[a place]” but perfectly natural when the LA Times writes “We found pp[in Santa Barbara] np[a place of health, comfort and luxury].) Existing theory posits this effect of “end weight” as a single, unified principle, even while the strength of this effect is known to vary across phenomena, far stronger in phrasal-verb separation, for example, than in prepositional-phrase ordering. This sets up an empirical question: Do individuals or communities indeed internalize this as a single principle, or might we learn our preferences individually and separately by construction in the process of acquiring language? We’ll explore this question via corpus and experimental studies.