You don't always need to use words to get your point across — you could just growl or yelp.
No matter what your cultural background, if you sob, scream or growl, others are likely to know what you mean, according to a new study.
And the cries you may make when you're in danger or upset are more universally understandable than those you might let out if you're feeling good, such as a cheer or a sigh of relief, the researchers say.
While several studies have looked at whether different facial expressions are recognizable to people all over the globe, few have examined the universality of so-called "nonverbal vocalizations," or the cries, grunts and laughs we all use to convey emotion without speaking, said study researcher Disa Sauter of the Max Planck Institute for Psycholinguistics, in The Netherlands .
In fact, no previous studies have compared the nonverbal noises of westernized cultures with those of extremely isolated groups who have had zero exposure to the modern world, she said.
For this task, Sauter and her colleagues turned to the Himba people, a group of over 20,000 living in small communities across northern Namibia, in southern Africa. Some of their settlements are extremely isolated, having no contact with people from other societies. Their culture has no writing system and no formal education.
The researchers wanted to see how well the Himba people understood European nonverbal vocalizations, and in turn, how well the Europeans deciphered the Himba nonverbal sounds.
Himba members were first read stories in their own language that were designed to elicit very specific emotions, such as one meant to elicit sadness about a man whose close relative had died. The story listeners were then asked, "How do you think this person is feeling?" and were played two sounds — one of a person crying, the other a sound not related to sadness (a so-called distracter sound). If crying means the same thing to Himba people as it does to Europeans, they should pick the right noise every time, and if not, their selections should be random.
(This story strategy does not require the Himba people to read, and it avoids any potential problems that might arise from translating words between the cultures, Sauter said.)
They found that the Himba people were more easily able to recognize sounds conveying negative emotions than positive ones. They correctly paired sounds for anger (growls), sadness, disgust (retches) and fear (screams) with their appropriate stories, and did so at a level that was higher than what you would expect by chance. They also accurately identified the sounds for surprise — considered a neutral emotion, because it is expressed in situations that are unexpected, but not necessarily good or bad.
They didn't do as well for positive emotions. The sound for amusement (laughter) was the only positive vocalization that the Himba people were able to recognize at a level that did not appear random.
Those in the European group were able to correctly identify all of the Himba nonverbal vocalizations, for both negative and positive emotions.
The mismatch in results between cultures "seems to suggest that maybe positive signals are something that we learn from those around us as we grow up, whereas the negative emotions seem to be something that's possibly more biologically determined," Sauter told LiveScience.
Specifically positive emotions "are thought to strengthen social bonds, and that might be something that you want to primarily do with the people of your own group," she said.
The results were published in the Jan. 25 issue of the journal Proceedings of the National Academy of Sciences. Sauter conducted the research as part of a Ph.D. thesis while at the University College London, in England. The work was funded by the Economic and Social Research Council, the University College London Central Research Fund, among others.