A study seems to suggest that warm hands foster an attitude of trust, so a winning way to seek a favour from someone might be to hand them a hot cup of coffee or tea first and then ask for a favour.
It is believed that we are programmed to seek out warmth and that a hot drink triggers a host of positive associations in the brain.
In the study, the volunteers were asked to hold a cold or a warm object before taking part in a game psychologists used to gauge how much we trust others.
Those with cold hands were less trusting and brain scans showed more activity in the insula, a region thought to be key to processing information about temperature and trust.
"Our interpretation is that cold activates insula, and activation spreads into areas influencing subsequent trust decisions," the Daily Mail quoted Professor John Bargh, of Yale University, as saying.
"Coldness may prime individuals to be less risk-seeking during ensuing decision making.
"This work provides compelling support for the view that physical temperature cues provide useful information regarding whether it is safe to trust others. We have demonstrated that brief experiences with cold or warm objects can influence people's social judgements and behaviour without their awareness," he added.
On the contrary, physical warmth may unconsciously 'prime' the brain into feeling more positive and more willing to give others a chance.
"The secret to instilling trust might be as simple as handing someone a hot cup of coffee," Bargh said.
The study appears in the journal Social Cognitive and Effective Neuroscience.