Taking meaning in hand: Iconic motivations in two-handed signs

Traditionally in sign language research, the issue of whether a lexical sign is articulated with one hand
or two has been treated as a strictly phonological matter. We argue that accounting for two-handed signs
also requires considering meaning as a motivating factor. We report results from a Swadesh list
comparison, an analysis of semantic patterns among two-handed signs, and a picture-naming task.
Comparing four unrelated languages, we demonstrate that the two hands are recruited to encode various
relationship types in sign language lexicons. We develop the general principle that inherently "plural"
concepts are straightforwardly mapped onto our paired human hands, resulting in systematic use of the
two hands across sign languages. In our analysis, "plurality" subsumes four primary relationship types –
interaction, location, dimension, and composition – and we predict that signs with meanings that
encompass these relationships – such as 'meet', 'empty', 'large', or 'machine' – will preferentially be twohanded
in any sign language.