Angry expressions seem to boost the effectiveness of threats making them seem more credible, according to a new research.
The findings show that angry expressions lend additional weight to a negotiator's threat to walk away from the table if his or her demands aren't met, leading the other party in the negotiation to offer more money than they otherwise would have, researchers said.
"Our facial expressions are relatively more difficult to control than our words," said psychological scientist Lawrence Ian Reed, first author on the research.
Because they are harder to control, these expressions serve as a believable outward indication of a person's motivations.
"In this way, facial expressions can carry the weight of our words," said Reed.
Reed and colleagues Peter DeScioli of Stony Brook University and Steven Pinker of Harvard University hypothesised that angry expressions may back up negotiators' threats to walk away from the table if they don't receive what they want.
In a study conducted online, 870 participants were told they would be playing a negotiation game in which some participants, acting as the "proposer," would decide how to split a sum of USD 1 with another participant, the "responder."
Each person would receive the specified sum if the responder accepted the split that was offered, but neither person would receive any money if the responder rejected the split.
Before making their offers, each proposer was shown a threat that supposedly came from the responder. The responder was played by the same female actor, who was instructed to create specific facial expressions in the video clips.
One clip showed her making a neutral expression, while another showed her making an angry expression.
The clips were accompanied by a written demand for either an equal cut of 50 per cent or a larger cut of 70 per cent, (which would leave only 30 per cent for the proposer).
After they saw the threat, the proposers were asked to state their offer.
The data showed that the responder's facial expression did have an impact on the amount offered by the proposer, but only when the responder demanded the larger share.
That is, proposers offered more money if the responder showed an angry expression compared to when they showed a neutral expression, but only when the responder demanded 70 per cent of the take.
Facial expression had no influence on proposers' offers when the responder demanded an equal share, presumably because the demand was already viewed as credible.
The research was published in Psychological Science, a journal of the Association for Psychological Science.