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Feel the warmth. Holding a warm cup may make you more generous.

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Warm Hands, Warm Hearts

Holding a hot cup of coffee warms your hands on a cold day--but it may warm your heart as well. Two experiments, reported in the 24 October issue of Science, suggest that the physical feeling of warmth makes people judge others more favorably and act more generously.

The perception of warmth or coldness is often used in everyday life to describe abstract concepts. "Cold eyes" suggest a distant or selfish personality; a "warm smile" is synonymous with kindness. Psychologists have long thought that this kind of common wisdom may be based on actual physical experiences, and recently, a team from the University of Toronto in Canada discovered that icy stares and social exclusion literally feel cold (ScienceNOW, 17 September). The two new experiments show that this can work the other way as well: Hot and cold sensations can influence one's feelings.

For the first experiment, psychologist Lawrence Williams (ScienceCareers, 2 March 2007) of the University of Colorado, Boulder, recruited 41 undergraduate students. When they walked into the laboratory, they were casually asked to hold a hot or cold cup of coffee for a moment. They were then given a brief fictional description of "Person A" and asked to rate 10 personality traits based on this summary. The students weren't aware that holding the cup was part of the experiment, but the "effect is quite meaningful and astonishing," says Williams. Those who held hot cups were more likely to assign positive traits, such as "generous," "caring," or "sociable" to Person A than those who held the cold cups.

The second experiment of the study was presented as a product evaluation study, in which 53 participants were asked to hold hot or cold therapeutic pads for a moment and then judge the quality of the product. At the end of the test, as a "reward" for their participation, they could choose either a reward for themselves or a voucher to give to a friend. Among those who handled a hot therapeutic pad, 54% chose the voucher for a friend, but only 25% of those who held the cold pad did.

The findings show that the perception of warmth and coldness has a clear effect on people's perceptions and social behaviors, Williams says. The effect could be used in marketing, he adds. For instance, when giving away free samples of new products, it might be more effective if they feel warm.

Tomas Chamorro-Premuzic, a psychologist specializing in consumer behavior at the University of London's Goldsmiths College, agrees: "In a sense, warm objects could be used in the same way romantic, emotional, or uplifting music is used for positive mood induction." But he adds that not everybody may react favorably; consumer research needs to pay attention to personality types, he cautions.