Hot coffee apparently has more power than anyone would have ever suspected, concludes a new Yale study that focused on how test subjects reacted to each other when holding either warm or iced mugs of the wonderful beverage. Their behavior towards the people they were assessing varied substantially, according to the temperature of their mugs.
 

The notions of a "warm" or "cold" person are a common part of our daily lives. Most people associate their acquaintances with one of these two, depending on the kind of relations they have with them. The recent study shows that temperature plays a significant role in forming opinions on someone. In the current test, participants were given fact sheets about people and asked to write down their impressions.
 

Those who were given steaming coffee to hold during the experiment showed an increased tendency to write positive things and to feel more connected to the people they were writing about. On the other hand, test subjects holding iced coffee mugs exhibited significantly lower attachment levels, as few of them described traits of warmth in regard to the data they were given about someone.
 

Psychologists say that this happens because the notions of "warm" and "cold" are not necessarily associated with their current meaning, but rather are perceived by the oldest part of our brain, the one that connects to their ancient and primitive meaning. The insular cortex is stimulated by shifts in temperatures. At times, this area can overreact and cause borderline personality disorder, a disease that makes the sufferer exhibit signs of not knowing who to trust.

 
"It appears that the effect of physical temperature is not just on how we see others, it affects our own behavior as well. Physical warmth can make us see others as warmer people, but also cause us to be warmer – more generous and trusting – as well," Yale psychology professor John A Bargh, the leader of the current study, explained.