How People Tawk Affects How Well You Listen

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People from different places speak differently – that we all know. Some dialects and accents are considered glamorous or authoritative, while others carry a definite social stigma. Speakers with a New York City dialect have even been known to enroll in speech therapy to lessen their ‘accent’ and avoid prejudice. Recent research indicates that they have good reason to be worried. It now appears that the prestige of people’s dialects can fundamentally affect how you process and remember what they say.

Meghan Sumner is a psycholinguist (not to be confused with a psycho linguist) at Stanford who studies the interaction between talker variation and speech perception. Together with Reiko Kataoka, she recently published a fascinating if troubling paper in the Journal of the Acoustical Society of America. The team conducted two separate experiments with undergraduates who speak standard American English (what you hear from anchors on the national nightly news). They had the undergraduates listen to words spoken by female speakers of 1) standard American English, 2) standard British English, or 3) the New York City dialect. Standard American English is a rhotic dialect, which means that its speakers pronounce the final –r in words like finger. Both speakers of British English and the New York City dialect drop that final –r sound, but one is a standard dialect that’s considered prestigious and the other is not. I bet you can guess which is which.

In their first experiment, Sumner and Kataoka tested how the dialect of spoken words affected semantic priming, an indication of how deeply the undergraduate listeners processed the words. The listeners first heard a word ending in –er  (e.g., slender) pronounced by one of the three different female speakers. After a very brief pause, they saw a written word (say, thin) and had to make a judgment about the written word. If they had processed the spoken word deeply, it should have brought related words to mind and allowed them to respond to a question about a related written word faster. The results? The listeners showed semantic priming for words spoken in standard American English but not in the New York City dialect. That’s not too surprising. The listeners might have been thrown off by the dropped r or simply the fact the word was spoken in a less familiar dialect than their own. But here’s the wild part: the listeners showed as much semantic priming for standard British English as they did for standard American English. Clearly, there’s something more to this story than a missing r.

In their second experiment, a new set of undergraduates with a standard American English dialect listened to sets of related words, each read by one of the speakers of the same three dialects: standard American, British, or NYC. Each set of words (say, rest, bed, dream, etc.) excluded a key related word (in this case, sleep). The listeners were then asked to list all of the words they remembered hearing. This is a classic task that consistently generates false memories. People tend to remember hearing the related lure (sleep) even though it wasn’t in the original set. In this experiment, listeners remembered about the same number of actual words from the sets regardless of dialect, indicating that they listened and understood the words irrespective of speaker. Yet listeners falsely recalled more lures for the word sets read by the NYC speaker than by either the standard American or British speakers.

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Figure from Sumner & Kataoka (2013) showing more false recalls from lists spoken with a NYC dialect than those spoken in standard American or British dialects.

The authors offer an explanation for the two findings. On some level, the listeners are paying less attention to the words spoken with a NYC dialect. In fact, decreased attention has been shown to both decrease semantic priming and increase the generation of false memories in similar tasks. In another paper, Sumner and her colleague Arthur Samuel showed that people with a standard American dialect as well as those with a NYC dialect showed better later memory for –er words that they originally heard in a standard American dialect compared with words heard in a NYC dialect. These results would also fit with the idea that speakers of standard American (and even speakers with a NYC dialect) do not pay as much attention to words spoken with a NYC dialect.

In fact, Sumner and colleagues recently published a review of a comprehensive theory based on a string of their findings. They suggest that we process the social features of speech sounds at the very earliest stages of speech perception and that we rapidly and automatically determine how deeply we will process the input according to its ‘social weight’ (read: the prestige of the speaker’s dialect). They present this theory in neutral, scientific terms, but it essentially means that we access our biases and prejudices toward certain dialects as soon as we listen to speech and we use this information to at least partially ‘tune out’ people who speak in a stigmatized way.

If true, this theory could apply to other dialects that are associated with low socioeconomic status or groups that face discrimination. Here in the United States, we may automatically devalue or pay less attention to people who speak with an African American Vernacular dialect, a Boston dialect, or a Southern drawl. It’s a troubling thought for a nation founded on democracy, regional diversity, and freedom of speech. Heck, it’s just a troubling thought.

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Photo credit: Melvin Gaal, used via Creative Commons license

Sumner M, & Kataoka R (2013). Effects of phonetically-cued talker variation on semantic encoding Journal of the Acoustical Society of America DOI: 10.1121/1.4826151

Sumner M, Kim S K, King E, & McGowan K B (2014). The socially weighted encoding of spoken words: a dual-route approach to speech perception Frontiers in Psychology DOI: 10.3389/fpsyg.2013.01015

A New America of Mutts?

8687286808_ce53c853e7_oI recently wrote about my biracial daughter and public assumptions about inheritance for the blog DoubleXScience. Nearly the same day, columnist David Brooks’ op-ed piece, “A Nation of Mutts,” appeared in The New York Times. As you might imagine, I read it with interest.

In his column, Brooks writes about how the long-European roots of America are becoming outnumbered by those of immigrants from elsewhere in the world.  Add to that racial intermarriage and mixed-race offspring and you’re left with what Brooks calls the coming New America. What will this New America look like? Brooks is happy to venture guesses, predicting how the complex forces of socioeconomics, education, ethnicity and heritage may play out in coming generations. Among these predictions: that America will become “a nation of mutts, a nation with hundreds of fluid ethnicities from around the world, intermarrying and intermingling.” The piece sparked an outcry from readers and an online conversation via social media, much of it over his use of the term mutt. While it was obviously an unwise and insensitive word for him to use, I think this was the lesser of the problems with his piece.

According to New York Times public editor Margaret Sullivan, columnists are supposed to stir things up. But in “A Nation of Mutts,” Brooks merely takes a centuries-old argument, injects it with Botox, squeezes it into skinny jeans, and calls it something new.

He begins by telling us that “American society has been transformed” as increasing numbers of immigrants have come to the U.S. in recent decades. He adds that, “up until now, America was primarily an outpost of European civilization” with immigrants who came from Northern, Western, Southern, or Central Europe (depending on the era) but all “with European ideas and European heritage.” That is now changing. Brooks tells us that European-American five-year-olds are already a minority. We have thirty years, tops, before Caucasians will be the minority in America overall.

What strikes me is Brooks’ simplistic picture of racial and cultural differences. He portrays America’s past immigrants from Europe as a monolithic, homogeneous bunch (against which he will compare the diverse immigrants of today) when of course this is a straw man. Ask anyone at a European soccer championship match or at the Eurozone bailout negotiations whether Europeans all have the same “European ideas and European heritage.” On second thought, probably better you don’t.

Americans haven’t historically thought of all Europeans as similar or even equal. Take the 19th century Nativists, or Know-Nothings, who thought that immigrants were ruining America. What exotic nation supplied these immigrants? The Tropics of Ireland.

Our country’s long history of interracial children aside, Caucasians from all over Europe have been intermarrying in America for centuries. I have American ancestors dating back to colonial times and am part German and part British with at least one Frenchman and one Scot thrown in for good measure. Why does David Brooks consider my daughter a mutt yet doesn’t consider me one? Because my ancestors all had more or less the same skin color while my husband is several shades darker than me.

So what is David Brooks really recounting when he writes about the coming nation of mutts? What’s so different about the immigrants of today? Mostly superficial details of appearance. Brooks’ New America is based on the preponderance of pigments in skin, the shape and slope of eyes, the texture of hair. His seemingly profound comment is about the spread of a handful of genes that create innocuous (but visible) proteins like melanin. Big frickin’ deal.

Ultimately, David Brooks is guilty of recycling the same tired old tune: immigrants are changing America and who knows what it might become when they’re done with it? Of course immigrants change our national demographics and  cultural melange. Each generation has wrestled with this self-evident fact for different reasons and in different ways. But if there is anything constant about America’s history, it is the presence of immigration and continuous change. Which means that Brooks was wrong when he said that a New America is coming. It has been here all along.

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Photo credit: Steve Baker on Flickr

Divvying Up Baby

I recently bought my baby new pajamas with a decal that says, “50% Dad + 50% Mom = 100% Me!” I couldn’t resist an outfit that doubles as both math and biology lessons. But on further reflection, I’ve realized that this simple formula is wrong in more ways than one.

To begin with, my baby doesn’t look like she’s 50% Mom. At best, she looks about 10% Mom. I’ve written before about how our daughter would be a mixture of traits from European and Indian peoples, reflecting her mom and dad’s respective heritages. Yet she arrived looking like a wholly Indian baby. This is fine, of course. I think she’s absolutely perfect with her caramel skin and jet black eyes and hair. But it’s hard to keep a straight face when friends politely ask us who we think she resembles. And when I’m out with her in public I’m aware that I look like her nanny, if not someone who’s stolen a baby. She truly doesn’t look like she’s mine.

How else is the formula wrong? Genetically. Sure, our daughter’s nuclear genes are comprised of DNA sequences from both my husband and me. But she has another sort of DNA in her body, one that literally outweighs the conventional type. This DNA lives in her mitochondria, the bacteria-like structures that populate our every cell. Mitochondria are like tiny internal combustion engines, generating all of our energy through respiration and releasing heat that makes us warm-blooded animals. Although mitochondria don’t have many actual genes, they each carry several copies of those genes. Multiply that by the 10 million billion or so mitochondria in our bodies and you’ll find that we each contain more DNA by weight for mitochondria than humans. And these mitochondrial genes are inherited entirely from the mother.

Mitochondrial genes can’t claim credit for your eye color, jaw shape, or intrinsic disposition. Their reach is mostly limited to details of your metabolism and your susceptibility to certain diseases. But mitochondrial DNA is significant for another reason: scientists use it to trace human lineages across the globe. After all, they don’t get reshuffled in each generation as our nuclear genes are. Mitochondrial inheritance can be traced back hundreds of thousands of years, following the maternal lineage at every generation. Unlike the historian’s genealogy, which often follows surnames passed down from fathers, the scientist’s genealogy is a tree built of mothers alone.

So it is through our mothers that our heritages can be traced into the distant past. In every one of her cells, my baby carries a map leading back through me and my mother and her mother and beyond . . . unbroken all the way back to our earliest origins as modern humans. And since my baby is a girl, she can continue that line. So long as she has a daughter and she has a daughter and so on, I will remain a part of that ongoing chain.

My condolences to all you men out there. Same to all you women who only had sons. You’ve passed on your nuclear genes and your child may be the spitting image of you, but your mitochondrial chain has been broken and you will be left out of the biologist’s tree. Although my daughter looks classically Indian, her mitochondrial DNA reveal only her European lineage. Despite the hair, eyes, and skin she inherited from her daddy, my baby’s mitochondria are mine all mine. She and I are links in a traceable chain of human life while my husband is nowhere to be found.

That’s something I can remember the next time I’m mistaken for the nanny.

Halfsies!

My husband spotted another one yesterday. A half-Indian, half-Caucasian blend. The woman had an Indian first and last name, but her features were more typical of a Persian ethnicity than either Indian or white. My husband overheard her describing her heritage and smiled. These days, with a half-Indian, half-white baby on the way, we’re hungry for examples of what our baby might look like. We’ve found a few examples among our acquaintances and some of my husband’s adorable nieces and nephews, not to mention the occasional Indian-Caucasian celebrity like Norah Jones. We think our baby will be beautiful and perfect, of course, although we’re doubtful that she’ll look very much like either one of us.

Many couples and parents-to-be are in the same position we are. In the United States, at least 1 in 7 marriages takes place between people of different races or ethnicities, and that proportion only seems to be increasing. It’s a remarkable statistic, particularly when you consider that interracial marriage was illegal in several states less than 50 years ago. (See the story of Loving Day for details on how these laws were finally overturned.) In keeping with the marriage rates, the number of American mixed race children is skyrocketing as well. It’s common to be, as a friend puts it, a “halfsie.” At least in urban areas like Los Angeles, being mixed race has lost the negative stigma it had decades ago and many young people celebrate their mixed heritages. Their unique combinations of facial and physical features can be worn with pride. But the mixture goes deeper than just the skin and eyes and hair.

At the level of DNA, all modern humans are shockingly similar to one another (and for that matter, to chimpanzees). However, over the hundreds of thousands of years of migrations to different climates and environments, we’ve accumulated a decent number of variant genes. Some of these differences emerged and hung around for no obvious reason, but others stuck because they were adaptive for the new climates and circumstances that different peoples found themselves in. Genes that regulate melanin production and determine skin color are a great example of this; peoples who stayed in Africa or settled in other locations closer to the Equator needed more protection from the sun while those who settled in sites closer to the poles may have benefited from lighter skin to absorb more of the sun’s scarce winter rays and stave off vitamin D deficiency.

In a very real way, the genetic variations endemic to different ethnic groups carry the history of their people and the environments and struggles that they faced. For instance, my husband’s Indian heritage puts him at risk for carrying a gene mutation that causes alpha thalassemia. If a person inherits two copies of this mutation (one from each parent), he or she will either die soon after birth or develop anemia. But inheriting one copy of the gene variant confers a handy benefit – it makes the individual less likely to catch malaria. (The same principle applies for beta thalassemia and sickle cell anemia found in other ethnic populations.) Meanwhile, my European heritage puts me at risk for carrying a genetic mutation linked to cystic fibrosis. Someone who inherits two copies of this gene will develop the debilitating respiratory symptoms of cystic fibrosis, but thanks to a handy molecular trick, those with only one copy may be less susceptible to dying from cholera or typhoid fever. As the theory goes, these potentially lethal mutations persist in their respective populations because they confer a targeted survival advantage.

Compared to babies born to two Indian or two Caucasian parents, our baby has a much lower risk of inheriting alpha thalassemia or cystic fibrosis, respectively, since these diseases require two copies of the mutation. But our child could potentially inherit one copy of each of these mutations, endowing her with some Suberbaby immunity benefits but also putting her children at risk for either disease (depending on the ethnicity of her spouse).

The rise in mixed race children will require changes down the road for genetic screening protocols. It will also challenge preconceived notions about appearance, ethnicity, and disease. But beyond these practical issues, there is something wonderful about this mixing of genetic variants and the many thousands of years of divergent world histories they represent. With the growth in air travel, communication, and the Internet, it’s become a common saying that the world is getting smaller. But Facebook and YouTube are only the beginning. Thanks to interracial marriage, we’ve shrunk the world to the size of a family. And now, in the form of our children’s DNA, it has been squeezed inside the nucleus of the tiny human cell.

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