The Branching Direction Theory of Word Order Correlations Revisited1

In Dryer (1992a), I presented evidence from a sample of 625 languages on which pairs of elements correlate with the order of object and verb, and which do not (Greenberg 1963). I argued that the word order correlations reflect a tendency for languages to be consistently left-branching or consistently right-branching, what I referred to as the Branching Direction Theory (the BDT), and proposed that this tendency reflects processing difficulties associated with mixing left- and right-branching. The predictions of the BDT depend heavily, however, on one’s assumptions about constituent structure. A number of the correlations require assuming fairly hierarchical constituent structures, and are not predicted by the BDT if one assumes flatter constituent structures. In this paper, I discuss a number of these correlations, arguing that some of them can be explained by a combination of processing considerations and other principles, while a few remain unexplained under assumptions of flat constituent structures. 1. What correlates with the order of object and verb? While my current database is considerably larger than it was at the time I wrote Dryer (1992a), now containing at least partial data for over 1500 languages, the additional languages do not change the evidence presented in Dryer (1992) as to which pairs of elements correlat