Emma was the most popular baby girl name of 2008, the Social Security Administration announced today, supplanting Emily, which had held the slot for the past 12 years.

Both names, though, reflect a much deeper and largely unnoticed naming trend, which has played out over decades. At the beginning of the last century, names beginning with vowels, like Amanda, dominated the name popularity charts. But slowly their usage fell, bottoming out in the middle of the century as the consonant names, like David or Donna, rose to prominence. Recently, the vowels have been creeping back up to dominance.

Looking at the Baby Name Wizard Voyager charts, we had to wonder: What happened? Theories leapt to mind. Perhaps names beginning with consonants were "stronger" sounding? Perhaps it had something to do with the civil rights movement or immigration or biblical names or something that had some obscure connection to the Soviets? Surely, this pattern had to mean something, this mid-century preference for Bill (and Biff) and Sally over Ethan and Allison.

Maybe not, say sociologists and psychologists. In aggregate, the popularity of baby names are merely driven by the rules of fashion. By a process known as the "ratchet effect," the names change slowly, as millions of individuals just happen to like names that sound kind of, but not too much, like ones they know.

"Parents are really bad at knowing why we like certain names," said Laura Wattenberg, who built The Baby Name Wizard, which allows users to visually manipulate Social Security Administration name data. "I've never heard a parent say, 'I'm looking for a name that starts with a vowel.'"

Yet, unbeknownst to them, the naming zeitgeist seeps into their minds. Even culturally linked naming changes, like the terrifying rise of the name Miley (after the Disney star Miley Cyrus), occur within the framework of the larger cultural preferences for certain types of names, said Cleveland Evans, an expert in onomastics (the study of naming) at Bellevue University in Nebraska.

"You can see individual names that a pop culture thing did, but they are able to do these things because it fit into the ratchet effect already," Evans said. "If a celebrity has a name that fits in with the 'different, but not too different' thing, then it booms."

And the name's internal poetics, the way it sounds — the toughness of Tommy versus the rounded Owen, the music of Marissa versus the Betty's bounciness?

"It has no meaning," says Harvard sociologist, Stanley Lieberson, who authored an authoritative work on the subject, A Matter of Taste: How Names, Fashions, and Culture Change. "It's a chance factor."

Lieberson's data shows that real substantive changes occur, but simply as a function of varying parental preference for just how different their children's names should be. Over time that preference has shifted toward more novel names. Fewer and fewer people are picking the very most popular names. In the early part of the century, one in four babies were given one of the top 10 most popular names. Now, the most popular name (Emma) will be attached to barely one percent of the year's babies.

Whether or not this basic variable in the ratchet effect has a cultural basis or is yet another chance variation in American naming conventions is a matter of debate.

Psychiatrists Jean Twenge and W. Keith Campbell argue in their recent book, The Narcissism Epidemic, that the decrease in preference of the most popular names "says a lot about our culture."

"Naming rituals are central to cultures around the world and always have been. The names we choose for our children reveal our deepest wishes and desires," they write. "We now wish so fervently that our children will stand out from the crowd that we equip them with unique labels from birth."

While that's a compelling narrative, Evans says it could just be that, thanks to sites like Wattenberg's, parents know what the most popular names are now. Perhaps parents of the past thought they were picking less popular names, but were, in fact, unintentionally following the fashions of the time.

Now that everyone relentlessly Googles baby names, parents have no excuse if they saddle their kids with the most popular names. But Wattenberg says they still want names that sound popular, so they end up choosing endless variations on phonetic schemes that happen to be popular: Ava, Emma, Ella, Bella.

"What's hard for parents is that what feels like your own personal taste, it's everybody's taste," Wattenberg says. "It's a no win situation - if you pick a name you like, probably everybody else will like it too."

And that's what's fascinating about watching the nation-level trends in baby naming. The national nomenclature is transformed living room by living room as one frazzled couple after another makes a seemingly personal decision for underlying phonetic reasons they haven't considered.

"People may think they named a child after great, great grandma Olivia, but they have a lot of great, great grandmas, and they picked Olivia because it fits the popular sounds," Wattenberg says.

And that's how a country's culture changes: People cherry-picking from the past as they look for a name to call the future.

Wired Science editor Betsy Mason contributed to this report.

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Image: Baby Emma. Flickr/momboleum

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