Babies May Have Full-Blown Language System Built In

Hearing a baby babble wouldn't tell you this, but children are sensitive to grammar at an astonishingly young age, as a a growing number of leading language scientists are discovering. For example, when very young children first learn to speak, their sentences don't include words like "the" or verbs ending in "-ed" or "-ing" -- but they are sensitive to these parts of language, called "grammatical morphemes," a psycholinguist at The University of Arizona in Tucson has found.

LouAnn Gerken is an associate professor in the UA department of speech and hearing sciences, and is among scientists whose work is featured in the June 15 U.S. News and World Report cover story, "Baby Talk," by Shannon Brownlee.

Gerken's research shows how children depend on grammatical morphemes as cues to whether words are nouns or verbs, even though they omit these parts of language in their own speech when they first start to talk.

Gerken last February was part of a panel of scientists at the American Academy for the Advancement of Science (AAAS) meeting in Washington, D.C., for the session, "Born to Speak: Universal Grammar in First Language Acquisition."

The panel was organized to address the controversy over whether children acquire a fully powerful language system from the beginning or whether they pass through a primitive stage in which their language is considerably less powerful than that of adults.

The controversy is of great interest, Gerken said, "because at the broadest level, it speaks to the human condition. All animals communicate, but if it turns out that humans are the only animals with this very powerful system that we call language, then why is that? Chimps or gorillas are quite smart. So what is it about humans that allows us to have this incredibly powerful communication system?

"The big question that I'm asking is about children's sensitivity to grammatical morphemes in language. That's interesting for two reasons. First, kids don't say those things in their earliest language productions. Two, grammatical morphemes are probably the most important aspects of language signaling what a noun is or what a verb is.

"Nouns are things that have 'the' and 'a' in front of them,and verbs are things that have '-ing' and '-ed' after them. So if kids don't notice those things, then it would be very hard for them to figure out other aspects of language. Grammatical morphemes are an important anchor into language."

Gerken cited research results from several studies that show how important grammatical morphemes are to children for language comprehension.

In the first study, Gerken and a colleague tested two-year-olds who didn't produce any grammatical morphemes in their own speech. Their subjects were more likely to choose a correct picture when asked in sentences using grammatically correct morphemes (85 percent correctly responded to "Find the dog for me") rather than in sentences with incorrectly used morphemes ("Find was dog for me" elicited a correct response from 55 percent) or nonsense syllables ("Find gub dog for me" got a correct response from only 40 percent).

In another study, Gerken and colleagues attached electrodes to the scalps of 11- and 12-month-olds and read to the infants from a story book. When the researchers replaced the grammatical morphemes with nonsense syllables, the year-old babies showed a different pattern of brain responses for the two types of passages, suggesting that they indeed noticed the difference.

Gerken cited her own and other research demonstrating that young children omit grammatical morphemes in their own speech that don't fit a particular rhythmic pattern. (English-speaking toddlers omit grammatical morphemes because of physical constraints on speech production, she said.)

"These data effectively rule out the idea that children's omissions of grammatical morphemes reflect the use of a less powerful language system than seen in adults," Gerken concludes. "In other words, we are free to consider the possibility that infants and children are prepared to entertain a fully powerful system from the beginning." [Contact: LuAnn Gerken]

12-Jun-1998

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