1. Introduction

Reciprocity lies at the heart of social cognition, and with it so does the encoding of reciprocity in language via reciprocal constructions. Despite the prominence of strong universal claims about the semantics of reciprocal constructions, there is considerable descriptive literature on the semantics of reciprocals that seems to indicate variable coding and subtle cross-linguistic differences in meaning of reciprocals, both of which would make it impossible to formulate a single, essentialising definition of reciprocal semantics. These problems make it vital for studies in the semantic typology of reciprocals to employ methodologies that allow the relevant categories to emerge objectively from cross-linguistic comparison of standardised stimulus materials. We situate the rationale for the 20-language study that forms the basis for this book within this empirical approach to semantic typology, and summarise some of the findings.