We all know how much emotion can be conveyed by a simple touch, whether we're stroking our partner's hand or receiving a soothing backrub from a friend. But research has largely ignored the role of touch in communication, instead focusing on communication through facial expression and tone of voice.
A recent study published in the journal Emotion offers the first investigation of the emotional expressiveness of touch in a natural setting, and its results are striking. In the study, researchers asked participants to communicate a series of emotions to a randomly assigned blindfolded partner by using any kind of touch the participants chose (so long as they kept their touch to appropriate parts of the body). These emotions included anger, fear, happiness, sadness, and disgust, as well as love, gratitude, and sympathy–three "prosocial" emotions, meaning emotions involved in positive feelings between people. The blindfolded partner was instructed to identify each emotion based solely on the other's touch.
Participants were able to convey these discreet emotions successfully most of the time. But what was especially interesting was that the blindfolded partners could not only identify love, gratitude, and sympathy but could differentiate between them, something they had not been able to do as well in studies of facial and vocal communication. By varying the intensity, speed, location, and duration of their touches, it seems, the participants were able to convey the subtle differences between these positive emotions.
These findings suggest that touch is not only important to emotional communication but also that it is intimately involved in the expression of positive emotions between people. This is consistent with what researchers have found elsewhere in the animal kingdom. Among many other primate species, for example, grooming is key to social bonding, suggesting an evolutionary explanation for why humans are so skilled at communicating positive feelings through touch.
"It is plausible that humans' tactile communication system may have evolved from the intricate system of tactile contact evident in nonhuman primates," write the researchers, among them Greater Good Executive Editor Dacher Keltner. Still, they note that more research is necessary to pinpoint the evolutionary significance of touch, and to determine whether these findings hold across cultures.