Physical warmth affects our judgments of others and our behaviour towards them

We often draw on physical metaphors when we think and talk about our feelings. We might describe someone as having a warm heart. Or we'll speak of a wrong-doer as washing their hands of a crime.

Past research has shown that this mental link with the physical world may be due partly to the fact that the same brain regions that represent bodily states such as warmth, also respond to their psychological equivalents like trust.

Now Lawrence Williams and John Bargh have taken things further by providing a compelling behavioural demonstration of how physical and psychological warmth are linked, and specifically how the former can actually influence our judgements of others and our behaviour toward them.

In an initial experiment, 41 participants held either an iced coffee or a hot coffee for 10 to 15 seconds while travelling in a lift towards a psychology lab. The coffee was passed to them by a research assistant as she took down their names. Once upstairs, the participants assessed two cars (to distract them from the true purpose of the study) and then rated the personality of a fictional "person A" who they were told was intelligent, skillful and industrious.

The intriguing finding is that the participants who'd earlier held a hot coffee rated the man more "warmly", for example describing him as more good-natured and generous, than the participants who'd held an iced coffee. Personality ratings unrelated to warmth/coldness, such as attractiveness or talkativeness, were unaffected by which coffee had been held, thus showing that this wasn't just a non-specific effect on mood. Also, none of the participants guessed the true purpose of the study.

A second experiment followed a similar pattern except participants were asked to rate a hot or iced therapeutic pad, and then to choose a reward for their time. Crucially, compared with the participants who rated the ice pad, those who rated the hot pad were subsequently more likely to choose (as a reward for participating) a drinks or ice-cream gift-voucher for a friend than to opt for a free drink or ice-cream for themselves.

"Experiences of physical temperature per se affect one's impressions of an prosocial behaviour toward other people, without one's awareness of such influences," the researchers said. The new results also appear to support Solomon Asch's intuition, published in the first half of the last century, that the warm-cold dimension is central to the first impressions we form of other people.

References

L. E. Williams, J. A. Bargh (2008). Experiencing Physical Warmth Promotes Interpersonal Warmth Science, 322 (5901), 606-607 DOI: 10.1126/science.1162548