Proceedings of the Annual Meeting of the Cognitive Science Society

We present an analysis of a treebank of spontaneous English dyadic conversations, investigating whether the degree of syntactic priming found across speakers is a function of the degrees of a?ective alignment and over- all positivity of the speakers. We use information theory to measure the proportion of overlap between the syn- tactic structures of the speakers. The a?ective state of the speakers is indexed by aggregated measures of the a?ective valences of the words they use. We ?nd that there is a positive relation between syntactic priming and a?ective alignment, over and above any lexical rep- etition e?ects. This constitutes evidence for the percola- tion of inter-speaker alignment across multiple levels of representation. This also illustrates the indexical value of syntactic alignment, as has been proposed in modern functional theories of grammar such as Dialogic Syntax.