In laboratory tests, left- and right-handers associate positive ideas like honesty and intelligence with their dominant side of space and negative ideas with their non-dominant side. To find out whether people link ‘good' with ‘dominant' beyond the laboratory, Casasanto and co-author Kyle Jasmin examined spontaneous gestures during positive and negative speech in the final debates of the most recent US presidential elections.
The 2004 and 2008 elections involved two right-handers (Kerry, Bush) and two left-handers (Obama, McCain). Casasanto and Jasmin found that right-handed candidates made a greater proportion of right-hand gestures when expressing positive ideas and left-hand gestures when expressing negative thoughts. But the opposite was found for the left-handers, who favored their left hand more for the positive and their right hand for the negative.
Across many cultures, expressions in language link ‘good' with right (the right answer) and ‘bad' with left (two left feet). Likewise, classical treatises instruct politicians to gesture mostly with their right hand, and only to use their left hand when delivering bad news.
‘Right' and ‘left' are also linked with political views, but the candidates' spontaneous gestures did not follow party lines. Both right-handers showed the ‘good is right' pattern, and both left-handers the ‘good is left' pattern. The association of good things with one's dominant side is something Democrats and Republicans appear to agree on.
So, the hand people use to make most of their gestures with may be a clue to whether they think what they are saying is good or bad, as long as you know their dominant hand. As us lefties are in a minority, is it possible that because we mainly use our left hand for gestures about good things, the righties may actually get the impression that we think it is actually bad?
This is getting too complicated but it is an interesting thought! If you want to know more, this is a link to the original research paper.