Human expressions of pain found to be universally similar: Study

The study challenges the long-standing notion that language is entirely arbitrary.

A recent study has revealed that human expressions of pain share striking similarities across languages, suggesting these responses may have roots in nonlinguistic vocalisations. The research, published in the Journal of the Acoustical Society of America, examined “pain words” or interjections in over 130 languages, uncovering consistent patterns in the sounds used to express pain globally.

The study was conducted by researchers Maia Ponsonnet from the University of Western Australia, Christophe D. M. Coupé from the University of Hong Kong, and Kasia Pisanski from France’s Centre national de la recherche scientifique (CNRS). The team focused on understanding whether interjections—standalone words like “ouch!” or “wow!”—feature common sounds tied to specific emotions such as pain, disgust, and joy.

Researchers analysed over 500 interjections from 131 languages across Africa, Asia, Australia, and Europe. They also examined nonlinguistic vocalisations, such as moans and cries, to identify links between these instinctive sounds and linguistic interjections. The study found that pain interjections frequently contained vowels like “a,” “ai,” or “au,” as seen in “ouch!” (English) and “ay!” (Spanish).

These sounds appeared more commonly in pain interjectionsthan in expressions of disgust or joy. Statistical tests showed that these patterns were not random; instead, they reflected consistent acoustic properties tied to expressions of pain.

“We found that pain interjections have markedly more ‘a’ vowels or vowel combinations like ‘ai’ or ‘au,’ which are more likely to occur compared to disgust or joy interjections, or other random words,” the researchers explained.

Interestingly, interjections for disgust and joy did not show similar patterns. Vowels in these expressions were distributed more randomly, highlighting that pain interjections are uniquely shaped by their connection to instinctive vocalisations.

The team also analysed nonlinguistic vocalisations—raw, instinctive sounds like groans or cries—from speakers of English, Japanese, Mandarin, Spanish, and Turkish. These findings further reinforced the link between pain interjections and nonlinguistic sounds. Pain vocalisations predominantly featured “a” vowels, while disgust vocalisations leaned towards neutral, central vowels, and joy vocalisations included more “i” vowels.

This correlation suggests that pain interjections may derive from the spontaneous, nonlinguistic sounds humans produce when experiencing pain. However, no such relationship was found for disgust or joy interjections, which appear to be shaped more by linguistic convention.

The study challenges the long-standing notion that language is entirely arbitrary. While words like “house” in English and “casa” in Spanish are thought to have no inherent connection to their meanings, pain interjections demonstrate that some linguistic forms may emerge from embodied human experiences.

“Pain, a universal and deeply emotional experience, is so central to human life that the spontaneous sounds it provokes might have influenced the conventional words we use to express it,” the researchers noted.

This groundbreaking study opens the door for further exploration into the origins of language. The researchers emphasised the need to examine consonants and other emotions beyond pain, disgust, and joy to build a fuller understanding of how human experiences shape language.

The study was supported by funding from France’s CNRS and the National Research Agency. While co-author Kasia Pisanski received funding for related research, the authors disclosed no financial interests that could influence their findings.