Abstract
BACKGROUND: According to the body-specificity hypothesis, people with different bodily characteristics should form correspondingly different mental representations, even in highly abstract conceptual domains. In a previous test of this proposal, right- and left-handers were found to associate positive ideas like intelligence, attractiveness, and honesty with their dominant side and negative ideas with their non-dominant side. The goal of the present study was to determine whether 'body-specific' associations of space and valence can be observed beyond the laboratory in spontaneous behavior, and whether these implicit associations have visible consequences. METHODOLOGY AND PRINCIPAL FINDINGS: We analyzed speech and gesture (3012 spoken clauses, 1747 gestures) from the final debates of the 2004 and 2008 US presidential elections, which involved two right-handers (Kerry, Bush) and two left-handers (Obama, McCain). Blind, independent coding of speech and gesture allowed objective hypothesis testing. Right- and left-handed candidates showed contrasting associations between gesture and speech. In both of the left-handed candidates, left-hand gestures were associated more strongly with positive-valence clauses and right-hand gestures with negative-valence clauses; the opposite pattern was found in both right-handed candidates. CONCLUSIONS: Speakers associate positive messages more strongly with dominant hand gestures and negative messages with non-dominant hand gestures, revealing a hidden link between action and emotion. This pattern cannot be explained by conventions in language or culture, which associate 'good' with 'right' but not with 'left'; rather, results support and extend the body-specificity hypothesis. Furthermore, results suggest that the hand speakers use to gesture may have unexpected (and probably unintended) communicative value, providing the listener with a subtle index of how the speaker feels about the content of the co-occurring speech.