(MICHAEL SLOAN FOR THE WASHINGTON…)
A friend recently asked me whether black bears in Appalachia have Southern accents and whether they have trouble understanding black bears raised in Canada or Alaska. Taken literally, those are notions more fit for a Disney movie than a scientist. In a more abstract sense, however, it’s a profound inquiry that fascinates zoologists and psychologists alike.
Is communication learned or innate in nonhuman animals? Can geographically distant groups of the same species develop local culture: unique ways of eating, playing and talking to each other? I posed those questions to Darcy Kelley, a Columbia University professor who studies animal communications.
“In most species, communication appears to have a genetic basis,” she said. “Regional accents can only develop in the small number of species that learn their vocalizations from others.”
Research suggests that the overwhelming majority of animals are born knowing how to speak their species’s language. It doesn’t really matter where those animals are born or raised, because their speech seems to be mostly imprinted in their genetic code.
University of Pennsylvania psychologist Bob Seyfarth and biologist Dorothy Cheney conducted a classic experiment on this question. They switched a pair of rhesus macaques and a pair of Japanese macaques shortly after birth, so that the Japanese macaque parents raised the rhesus macaque babies, and the rhesus macaque parents raised the Japanese macaque babies. This particular inter-species switcheroo is interesting because the two primate species communicate using most of the same sounds — coos, gruffs, barks and screams — although they don’t use them in the same contexts. Young rhesus macaques, for instance, tend to gruff during play, for example, while Japanese macaques tend to coo.
Seyfarth and Cheney found that foster parenting had little effect on the vocal patterns of the primates. The Japanese macaques continued to coo during playtime, even though all of their rhesus playmates were gruffing. This strongly suggests that macaques are born knowing when to coo, gruff, scream or bark, and that life experience and social conditions have no impact on their communication patterns. In other words, you can’t teach a rhesus macaque to speak like a Japanese macaque.
The implication is that macaques probably could develop regional accents only if they lived apart for thousands of years, long enough for their genetic speech patterns to diverge. That’s different from what we think of when we talk about accent differences in humans.
Birds do it; bats do it
Don’t pat yourself on the back for our unique language-leaning abilities, though. Humans are not quite alone in our ability to acquire language.
“Songbirds are fantastic learners,” says Ofer Tchernichovski, who studies bird communications at Hunter College in New York. “A nightingale can learn to sing 60 different songs after hearing them only a few times.”
Individual members of the same songbird species sing different songs based on their home town. White-crowned sparrows, whose range covers large portions of the United States, use about seven different sounds in their songs. But different population groups combine the sounds in different ways, researchers have found. They seem to learn their local patterns in the first three months of their lives by listening to adults. Ornithologists can immediately identify a white-crowned sparrow’s place of birth from its song, just as you can often tell a South Bostonian or a Louisianian from his distinct accent.
Dolphins, whales, hummingbirds and bats also have a proven ability to learn new vocalizations, and they probably exhibit what we would consider regional accents. Sperm whales in the Caribbean, for example, use different clicking patterns from those in the Pacific. Most other animal species, however, seem to to be more like macaques than men: They’re born knowing how to vocalize, and it doesn’t matter where they’re born.
Keep in mind that there’s a difference between learning to say new words and learning to understand them. It seems that many more animals can do the latter than the former. Remember the macaques from Seyfarth and Cheney’s study? Even though the adopted young never vocalized like their foster brothers and sisters, the adoptive parents raised them without any trouble. When the infants called out for food or comfort, the parents responded, even though they were basically speaking a different language. And some dogs have learned to understand more than 1,000 human words and some simple sentences.
Getting the message
This raises an intriguing question: If animals can learn to understand and respond to foreign languages, why can’t they learn to speak them? The answer may lie in a Darwinian imperative.
“Many biologists think that proper vocal communication is so important that a species can’t risk it being infinitely malleable,” says Columbia University’s Darcy Kelley. “It’s crucial to mating and announcing the presence of predators, which is the basis of survival.”
It’s just a hypothesis, but a powerful one. Due to the huge number of word combinations and accents in human communication, think of the number of times in a day when you have to say “What?,” “Pardon me?” or “Come again?” when someone speaks too fast or in an accent, foreign or domestic, that your ear hasn’t tuned in to well. Often, all you missed was “Please pass the salt” or something similarly inconsequential. But just imagine if it was slightly more important, such as “Look out for that hungry tiger!”