2933605871_601998ca2dIn social species, prosocial emotions are those that promote the well-being of the group. By engaging in acts of trust and cooperation, social groups survive. Parents and offspring form attachments, and individuals act in mutually beneficial, altruistic ways to sow trust between one another. A growing number of studies on touch and emotion reveal our deep-seated need for human contact and warmth. Touch may be the key for communicating prosocial emotions, and for promoting group cohesion and survival.

Dr. Dacher Keltner from the UC Berkeley Department of Psychology and Dr. Matthew Hertenstein (now at DePauw University) have conducted extensive research on how touch communicates emotions. In their 2006 paper Touch Communicates Distinct Emotion, Keltner and Hertenstein investigated the ability of touch to convey various emotions. Given the importance of cooperation and altruism in social groups, Keltner and his colleagues hypothesized that it should be possible to communicate prosocial emotions through touch alone. For their study, 212 volunteers between the ages of 18-40 were sorted into pairs called dyads. In each dyad, one person did the touching (the “encoder”) and the other received the touch (the “decoder”).

Each dyad sat at a table that was bisected by an opaque black curtain, and had no opportunity see or hear one another. The decoder was instructed to place a bare forearm through the curtain. On the other side of the curtain was the encoder, who presented one of twelve emotions to the decoder by touching the decoder’s exposed arm. In addition, the encoder was given freedom to choose how best to communicate each of the emotions, including anger, disgust, fear, happiness, sadness, surprise, sympathy, embarrassment, love, envy, pride, or gratitude. The decoder then chose which of the twelve emotions best described what the encoder was attempting to communicate. Keltner and Herenstein found that anger, fear, and disgust were communicated at levels above chance (which was set at 25%) along with prosocial emotions such as love, gratitude, and sympathy.

Interestingly, this experiment revealed that we use consistent types of touch to communicate particular emotional states. Research assistants, unaware of the emotions that the encoders were instructed to communicate, monitored the “tactile displays” of the encoder on a second by second basis. Research assistants used a survey of coding systems that is routinely used by researchers investigating touch. The types of tactile displays, including tapping, stroking, squeezing, poking, pushing, and tickling, among others, were noted and quantified in terms of frequency, duration, and intensity. Although 106 different encoders participated in the experiment, they tended to use similar tactile displays to convey emotion.  For example, sympathy was most likely to be communicated with patting or stroking, while anger was most likely communicated with pushing.

In a 2009 paper that re-examined this data, Keltner and his team found some interesting patterns of gendered communication. The dyads were either Male-Female (where the encoder was male and the decoder was female, and vice-versa), Male-Male, or Female-Female. Only when the dyad consisted of males was anger communicated at greater-than-chance levels. Only when the dyad consisted of females was happiness communicated at greater-than-chance levels. Sympathy was communicated at greater-than-chance levels only when there was at least one female in the dyad. One of the more humorous findings of the study was how helpless men and women were at communicating specific emotions to one another. As Dr. Keltner explained in a public lecture, “When women tried to communicate anger to the man he had no idea what she was doing and he got nothing right. And when the man tried to communicate compassion to the woman she got zero right. She had no idea what he was doing.”