Humans currently speak more than 6,000 languages, from Abaza to Mandarin to Zulu. Some of these share common linguistic ancestors — like the family of Indo-European languages, which has about 3 billion speakers around the world — and some arose more independently. But regardless of their origins, even the most different-sounding languages may be more alike than we tend to think.

That's according to a new study, published this week by an international team of linguists, mathematicians and psychologists. They analyzed 40 to 100 basic words from 62 percent of all current human languages, representing 85 percent of linguistic lineages, to investigate links between the sounds and meanings of words.

People often use the same sounds for common objects and ideas, they found, no matter what language is being spoken. This goes beyond onomatopoeia — words like "buzz" or "boom" that imitate the sounds they describe — and includes an array of concepts such as body parts, animals and motion verbs. The sounds don't actually mimic what they represent, yet are still mysteriously linked to meaning.

"These sound-symbolic patterns show up again and again across the world, independent of the geographical dispersal of humans and independent of language lineage," says co-author and Cornell University psychology professor Morten Christiansen. "There does seem to be something about the human condition that leads to these patterns. We don't know what it is, but we know it's there."

couple talking in China The study's authors aren't sure why patterns of sound and symbolism exist across cultures, but they speculate it has something to do with signals we use when learning or processing language. (Photo: Brian C/Flickr)

Wired for sound

The researchers compiled basic parts of speech shared across languages, including pronouns, motion verbs and nouns. They broke these into a "phonologically simplified system" of 41 consonant or vowel sounds, then used a statistical approach to look for patterns. The analysis found 74 significant associations between sound and symbolism — even in unrelated languages from different lineages.

This finding "shatters a cornerstone concept of linguistics," according to a Cornell statement about the study, since researchers have long believed the sounds of most words are disconnected from their meaning. Look at languages with little or no direct relation, the study's authors say, like Russian, Swahili and Japanese. The respective words for "bird" in those languages are ptitsa, ndege and tori, for example, each of which uses sequences of different sounds to identify the same basic idea.

Lots of languages use similar sounds for certain concepts because they come from a common ancestor, or because they have a history of borrowing words from each other, so the researchers had to control for those kinds of relationships. Even then, their study suggests an innate link between many sounds and meanings.

Here are some examples:

  • The word for "nose" is likely to include the sounds "neh" or "oo."
  • The word for "tongue" is likely to have "l," as in the French langue.
  • The words for "red" and "round" tend to feature an "r" sound.
  • Words for "leaf" are likely to include the sounds "b," "p" or "l."
  • Words for "sand" tend to use an "s" sound.
  • Words for "stone" tend to use a "t" sound.

"It doesn't mean all words have these sounds, but the relationship is much stronger than we'd expect by chance," Christiansen says.

dog at Vatera Beach, Greece The word for 'dog' doesn't usually include a 't' sound, researchers say, but across languages it does tend to have an 's' sound — as in the Greek word skylos. (Photo: Konstantinos Mavroudis/Flickr)

The study revealed both positive and negative associations, which means words tend to either favor or avoid certain sounds. Aside from the positive associations listed above, for example, it found the word for "I" (as in "me") is unlikely to use sounds including "u," "p," "b," "t," "s," "r" or "l," while "dog" is unlikely to feature a "t" sound and "tooth" words seem to shy away from "m" and "b."

Words of wisdom

Scientists have found similar hints of sound-symbol patterns in recent decades, such as studies that showed words for small objects in various languages often contain high-pitched sounds. But while previous research looked at specific word-sound relationships, or small sets of languages, this study's analysis of several thousand languages makes it the most comprehensive investigation to date.

"People haven't been able to show whether sound symbolism is really something more pervasive throughout languages all over the world," Christiansen says. "And this is the first time anyone has been able to show that at such a scale."

Finding a pattern isn't the same as explaining it, however, and these newfound connections remain mysterious for now. Christiansen speculates they might help us build or process our vocabulary, since the study looked at basic words that children of all cultures tend to pick up early in life. "Perhaps these signals help to nudge kids into acquiring language," he says. "Likely it has something to do with the human mind or brain, our ways of interacting, or signals we use when we learn or process language. That's a key question for future research."

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.