It may just be that the key to Middle East peace is the "aawww" element.

Researchers at Hebrew University in Jerusalem have discovered that baby-faced Palestinian negotiators - those with proportionally larger eyes and thick, pudgy lips - are perceived as being kinder, warmer, more honest and more trustworthy, and so are likely to have more success convincing Israelis of their positions.

In contrast, those who look older are more likely to face tantrums when they work with the opposition.

Dr Ifat Maoz, who led the "Face of the Enemy" study, gave 80 Israelis fictional newspaper articles about the peace process, featuring the face of an unidentified Palestinian leader.

She came up with the project after learning of research into the powerful effect of facial features on people's trust in their own representatives.

According to Dr Maoz, past studies have found that people make judgments about their levels of trust, "after as little as 100 milliseconds' exposure to a novel face.

"I was interested to see how this applied to politicians from the enemy side, in a protracted violent conflict such as the Israeli-Palestinian one," she explained.

Her team edited pictures to make the face appear more, or less, mature, respectively shrinking or widening lips and eyes by 15 per cent.

Overwhelmingly, the panel judged "the baby-faced politician" as more trustworthy than his older self and gave more support to his peace proposal.

"Attitudes towards the opponent in conflict and towards peace were significantly shifted by subtle alterations that people were not even aware of," said Dr Maoz, whose study was the first of its type. She has been researching, for 20 years, the role of psychological factors on forging a peace deal.

She acknowledged that "in actual negotiations, other factors are at play" and that finding a path to peace required more than the election of a youthful-looking leader. "But we do seem to have quite strong theories about relationships between certain facial features and certain qualities, and these lay theories affect our impressions of others and behaviour towards them," she said.

Dr Maoz said that the next step would be to survey Palestinians in the same way, to determine whether a baby-faced Bibi would have any effect.