The tears of a crying grown adult elicit more sympathy from observers than the tears of a crying young child or infant, according to a study published in Evolutionary Psychology.
The research, published on August 12, investigated the role of tears in crying across the human lifespan. It was authored by Debra M. Zeifman of Vassar College and Sarah A. Brown of Haverford College.
“One possible reason tears are less useful for elaborating the meaning of the facial expressions of infants and children is that juvenile crying is predominantly an acoustic signal,” they explained.
Infants typically do not shed tears while crying until two or three months after birth, relying on purely vocalized crying.
“As vocal signaling of distress becomes voluntarily suppressed, visual cues of distress, such as emotional tearing, may gain significance because they are reliable signs of distress and are not easily inhibited,” Zeifman and Brown wrote.
Participants in the study viewed pictures of adults, young children and infants crying with and without visible tears.
The study found that although crying in general was not viewed as particularly irritating, the crying of adults was less irritating than the crying of children or infants. Participants in the study were also more irritated by crying faces without tears than crying faces with tears.
“A common explanation for the paradoxical effects of infant crying on listeners is that the aversive quality of infant crying underlies its effectiveness at recruiting actions aimed at stopping it,” Zeifman and Brown explained in their study. “In this model, irritation typically leads to intervention.”
While the crying of an infant may provoke the least sympathy and the most irritation, participants in the study reported being much more likely to comfort a crying infant than a crying adult. When shown a picture of a crying infant, 83 percent of the participants said they would attempt to comfort the infant in the photograph. Only 25 percent said they would attempt to comfort an adult.
The full study can be viewed here (PDF).