MONDAY, Aug. 2 (HealthDay News) -- If you want to know the true thoughts of a politician, watch his or her hand movements, a new study suggests.

"In laboratory tests, right- and left-handers associate positive ideas like honesty and intelligence with their dominant side of space and negative ideas with their non-dominant side," study author Daniel Casasanto, of the Max Planck Institute for Psycholinguistics in the Netherlands, said in an institute news release.

To find out if this link between "good" and "dominant" applies in the real world, Casasanto and colleague Kyle Jasmin studied tapes of the final debates in the 2004 and 2008 U.S. presidential elections.

The investigators found that right-handed candidates (John Kerry, George W. Bush) made a greater proportion of right-hand gestures when expressing positive ideas, and left-hand gestures when expressing negative thoughts, while the two left-handers (Barack Obama, John McCain) used their left hand more for positive ideas and their right hand for negative thoughts.

"Overall, the data support the idea that people associate good things with the side of their body they can use most fluently -- dominant is fluent, and fluent is good," Casasanto stated in the news release.

The hand that politicians use when speaking may offer insight into how they feel about what they're saying, he added.

The study was published online July 28 in the journal PLoS One.

More information

The Nemours Foundation has more about handedness.