The Cross-Linguistic Prevalence of SOV and SVO Word Orders Reflects the Sequential and Hierarchical Representation of Action in Broca's Area

Despite the increasingly interdisciplinary nature of the language sciences, so far relatively little effort has been devoted to exploring potential connections between typology and neuroscience. To illustrate some of the insights that can be gained from pursuing such an integration, this paper focuses on one of the most well established and frequently cited typological generalizations, namely that in the vast majority of human languages, the basic word order is either SOV (about 48%) or SVO (about 41%). It has been suggested that these strong tendencies can be explained cognitively in terms of the prototypical transitive action scenario, in which an animate agent acts forcefully on an inanimate patient to induce a change of state. Two forms of iconicity are especially relevant: first, because the agent is at the head of the causal chain that affects the patient, subjects usually precede objects; and second, because it is the agent's action, rather than the agent per se, that changes the state of the patient, verbs and objects are usually adjacent. The purpose of this paper is to show that this account converges with, and hence receives further support from, recent research on how actions are represented in the brain. Specifically, several lines of evidence are reviewed which suggest that Broca's area plays a pivotal role in schematically representing the sequential and hierarchical organization of goal-directed bodily movements, not only when they are performed and perceived in the real world, but also when they are conceptualized and symbolically expressed as transitive clauses. Taken together, these findings support the hypothesis that the most cross-linguistically prevalent word order patterns reflect the most natural ways of linearizing and nesting the core conceptual components of actions in Broca's area.