Horizon Magazine · People & society

What dogs can teach us about the origins of speech

Researchers are investigating how dogs communicate through sound to understand the evolution of human speech. A project called K9VocLearn is exploring whether domestication changed how dogs use their voices, potentially revealing insights into vocal learning, a key prerequisite for spoken language.

Dogs have lived alongside humans for over 14,000 years, becoming adept at reading human gestures and cues. Now, scientists believe dogs might offer clues to how humans became the only species capable of spoken language.

Dr. Tamás Faragó, a bioacoustics researcher at Eötvös Loránd University, is leading the K9VocLearn project, which examines canine vocal communication. The research aims to determine if domestication has influenced dogs' vocal abilities and what this could signify for the evolution of human speech.

The core of the research lies in vocal learning – the capacity to modify vocalizations by listening to others. This ability is considered crucial for spoken language, and scientists are investigating if thousands of years of cohabitation with humans have equipped dogs with some of its foundational elements.

While humans possess exceptional vocal learning abilities, other mammals like dolphins, whales, seals, bats, and elephants show varying degrees of sound imitation or modification. Great apes, our closest relatives, exhibit more limited vocal flexibility compared to dogs.

Dogs occupy a unique evolutionary position, having been selectively bred for traits beneficial to humans, such as tameness, social tolerance, and cooperation in tasks like hunting and herding. Researchers hypothesize that these same traits might have influenced their ability to control and alter their vocalizations.

This line of inquiry connects with the self-domestication hypothesis, which suggests that selection for social tolerance and cooperation in human evolution led to changes comparable to animal domestication. If greater social tolerance also promotes more flexible communication, studying dogs could shed light on the evolutionary conditions that enabled human speech.

Evidence suggests a shift in canine vocal behavior post-domestication. A 2023 study indicated that breeds genetically closer to wolves were more likely to howl in response to a howl, while those more distantly related tended to bark. Researchers believe the prevalence of barking in dogs, unlike wolves, is a direct result of domestication, possibly favored by early humans for alarm-raising.

At the Budapest BARKS Lab, researchers are meticulously documenting canine vocal communication by recording barks, whines, growls, and howls alongside behavioral and heart rate data during various emotional stimuli. This helps link specific vocalizations to emotional states.

The next phase involves assessing whether dogs can voluntarily produce sounds. Training protocols are being developed to encourage dogs to vocalize on cue without external triggers, with an emphasis on voluntary participation and the dog's ability to signal discomfort or fatigue.

The objective is not to teach dogs human-like speech but to understand their level of voluntary control over their sounds. For instance, researchers aim to see if a dog can be trained to produce an excited whine on command, without the usual trigger like a ball.

The project also includes dogs with minimal vocal repertoires, as all data is valuable. Even dogs that are not naturally "chatty" can learn to control their voices, demonstrating that vocal control is distinct from simply being vocal.

The research will expand beyond the lab through citizen science initiatives, inviting dog owners globally to submit recordings of various canine sounds. Owners will also contribute DNA samples and behavioral surveys to identify potential genetic links to vocal control.

Beyond understanding speech origins, the research has practical applications, such as developing smart devices to detect a dog's emotional state through vocalizations. This could improve animal welfare by helping owners recognize stress or fear, thereby strengthening the human-animal bond.

Ultimately, by studying how domestication may have gifted dogs a more flexible voice, researchers hope to uncover missing pieces in the evolutionary puzzle of how humans developed spoken language.

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