Although it was clear that there was a connection between the linguistic abilities of young babies and their future development, it was only recently that it became clear how linguistic abilities at the age of less than one year indicate linguistic abilities at a later age
Miriam Dishon-Berkowitz, Galileo
You are delighted with your baby, who is a few months old. The Zatot listens when you speak, produces syllables or turns its head when it recognizes certain words. What does this behavior teach about the linguistic abilities he will demonstrate at the age of two, four or six? A study published in the journal Developmental Psychology, the result of the work of a team led by Rochelle Newman (Newman, Bernstein-Ratner, Jusczyk, Jusczyk & Ayala Dow) shows that linguistic abilities at the age of less than one year predict linguistic abilities at later ages.
Although there is extensive research literature dealing with the linguistic development of children, and although it is reasonable to assume that there is a relationship between a baby's linguistic ability and the development of his future language skills, most studies in the field have examined differences between groups of babies, and not the relationship between the linguistic skills demonstrated by each individual baby and His future language skills. For example, the difference between the linguistic skills of a group of 9-month-old infants and those of a group of 15-month-old infants was examined. However, the difference between the linguistic skills of the same baby at the age of 9 months and his skills later, at the age of 15 months, has hardly been studied. why?
Long and expensive studies
First, the conduct of longitudinal studies - by their very nature - requires more time, and they are also more expensive. Second, when in a specific experiment a particular baby demonstrates excellent - or poor - performance, the accepted assumption is that one cannot learn from this performance about the baby's true abilities, but only about his behavior at the moment when the experiment was conducted. why? The dependent (measured) variable in most studies on small infants, who cannot yet speak or respond motorically in a controlled manner, is looking in a certain direction (for example, in the direction from which a familiar word was heard).
Anyone who is around babies knows that it is difficult for a small baby to concentrate on something for a long time, at least for the period of time needed for the experiment. Therefore, he may not turn his head towards a sound stimulus simply because he is hungry, because his diaper has not been changed or because he is tired. Therefore, if, for example, 18 out of 24 6-month-old infants turn their heads for a longer time toward a speaker when familiar words come from it than unfamiliar words, the conclusion is that infants of this age are able to recognize familiar words. And what about those six babies who did not react as expected? The accepted assumption was that they did not turn their heads for reasons unrelated to the experiment (fatigue, hunger, etc.). However, is this assumption really correct?
In the new study published in Developmental Psychology, Newman and her colleagues focus on that small group of babies who do not respond to stimulation like the other babies. Is their inability to perform the experimental task in the laboratory only due to the fact that they were, for example, tired that day, or does their behavior indicate lower abilities, which may indicate future difficulties in the development of their language skills at later ages?
To answer this question, where Newman and her colleagues examined data collected by Jusczyk and his colleagues in 2000-2001 on 412 infants aged 7 months to 7.5 year. In this study, Jusczyk and his colleagues examined the babies' ability to isolate a particular word from a sequence of words in a sentence. This ability is necessary (even for adults) for language learning and understanding. In our native language we do this automatically, but think about a situation where you are listening to a foreign language. Do you know when one word ends and another begins? In their study, Jusczyk and his colleagues repeated a single word (for example, "mug") over and over until it became familiar to the babies. Then the babies were played two recordings: one in which the word "cup" is mentioned several times, and one in which it is not mentioned. If the babies listened for a longer time to the recording that contained the word "cup" (listening was measured by looking towards the direction from which the sound came), the conclusion was that they could isolate words. Babies are able to perform this task at the age of XNUMX months.
In the first phase of their study, Newman and her colleagues reanalyzed Jusczyk and his colleagues' data, but now focused not on group differences, but on the individual infants. Jusczyk and his colleagues at the time followed the babies for several years, and also examined their vocabulary at the age of two. Newman and her colleagues examined the "excellent" group on the vocabulary test - those whose scores were in the top 15 percentiles - and the "struggling" group on the vocabulary test - those whose scores were in the bottom 15 percentiles. From a retrospective analysis of the data, it became clear that about 70% of the toddlers who excelled in the vocabulary test at the age of 7 successfully performed the word selection tasks already when they were 40 months old. However, only about 7% of the children who had difficulty with the vocabulary test at the age of XNUMX were able to perform these linguistic tasks when they were XNUMX months old.
Straight attitude to the early skills
How did the language skills of those outstanding and struggling children continue to develop? In the second phase of their research, Newman and her colleagues tracked down 27 children who had participated in the original study by Jusczyk and his colleagues, who had meanwhile reached the ages of four to six. 12 of them excelled in the vocabulary test at the age of two, and the rest had difficulty in it. The researchers tested the children in a series of tests that included an IQ test, a vocabulary test and tests of syntax, grammar and expression.
From the analysis of the results it became clear that the subjects' abilities to recognize single words in a sentence while infants predicted their language skills as expressed in vocabulary, syntax and grammar at the age of four to six years. In contrast, the ability to isolate words at 7 months of age did not predict expressive ability or IQ at later ages.
The ability to recognize individual words in a sequence of fluent speech requires both the ability to isolate the word, and the ability to store it in memory for future recognition. This is a necessary step in the acquisition of language skills, and is essential for the later development of the ability to attach meaning to the sound of the word. And here it becomes clear that difficulties in recognizing individual words already in infancy lead to difficulties in the development of vocabulary and other language skills at the age of two, four and six. From an applied point of view, it is important that in the future it will be possible to develop tests that will help identify children who may develop difficulties in their language acquisition skills. Once identified, it will be possible to help those children before their language difficulties get worse.
