Previous studies have suggested that hearing more words played a strong role in the development of children’s language skills, yet a recent study by cognitive scientists at MIT challenges this idea. The MIT scientists found that more than simply being exposed to many words, back and forth conversation between a child and an adult could be responsible for boosting the child’s response to language and facilitating their language development.
A Word Gap?
A 1995 study examined the relationship between words heard by children and their language development. The study found that children who came from higher-income families heard approximately 30 million more words during the first three years of their life than children from lower-income families did, and it was thought that this gap was responsible for many of the differences found in language development, reading comprehension, and vocabulary. Recently, MIT scientists conducted a study which suggests that back and forth conversation between a child and adult is more critical to development, and explains more of the language gap, than the simple number of words heard is.
The MIT study examined children between four to six years of age and recorded how many “conversational turns” (changes in the person speaking) occurred in their conversations. The researchers found that the number of conversational turns was strongly correlated with significant differences in the language skill and brain physiology of the children in the study. This correlation held constant even when other variables, such as education level or parental income, were taken into account.
Prior to this study, it wasn’t clear how the “word gap” affected developing regions of the brain. The team at MIT tried to determine how the word gap might affect the development of language by scanning the brains of children from various socioeconomic backgrounds. The researchers assembled the database they needed by utilized a system dubbed LENA (Langauge Environment Analysis). LENA makes a record of every word that the child either speaks themselves or is heard by that child. The parents of the children ensured that the child wore a recorder on them for two days, instructing the child not to take the recorder off until they went to sleep for the day.
The recordings were input into a computer program which extracted three critical features of the recordings: the number of words heard by the child, the number of words the child said, and the number of times a conversation between the child and the adult underwent a “conversational turn”.
Language Development And Conversational Turns
The researchers used functional magnetic resonance imaging (fMRI) to examine how different children’s brains responded to language in different ways that correlated with the numbers of conversational turns their conversations usually had. Children who experienced more complex, back and forth conversation displayed much greater activity in a region of the brain called Broca’s area while they listened to stories. Broca’s area is involved with language processing and speech generation.
When analyzing the data from the LENA system and the fMRI imaging, the researchers found that the number of conversational turns a child’s conversations had was tightly correlated with the child’s scores on tests of language skills, including grammar, verbal reasoning, and vocabulary.
Rachel Romeo, the lead author on the study and graduate student at Harvard and MIT, explains that what’s important isn’t just to talk at your child but to talk with your child. It isn’t about just “dumping language into your child’s brain”, says Romeo. Mere exposure to a high volume of words won’t help much unless the child can practice synthesizing words and phrases, which means having a back and forth conversation. Romeo explains that while the results support other recent findings by cognitive scientists, there’s still a popular idea that the language gap is primarily explained by the 30-million-word-gap and that accounting for the gap is simply a matter of dumping words into children. Yet their research suggests that interactive dialogue much more predictive of strong language skill development than just hearing a large vocabulary of words.
John Gabrieli, professor of cognitive science at the Grover M. Hermann Professor in Health Sciences and Technology and member of MIT’s McGovern Institute for Brain Research, explains that the analysis shows that the effect holds true regardless of socioeconomic status. Even though conversational switches are more likely to happen in families who have a higher socioeconomic status, the children who live in families of lower socioeconomic status displayed the exact same benefits of the conversational switches. Explains Gabrieli:
One of the things we’re excited about is that it feels like a relatively actionable thing because it’s specific. That doesn’t mean it’s easy for less educated families, under greater economic stress, to have more conversation with their child. But at the same time, it’s a targeted, specific action, and there may be ways to promote or encourage that.
Future Research Goals
The research team wants to conduct more research on the topic and see if the effects of conversation continue to hold true when techniques that increase the amount of conversation are brought into children’s lives. The research team hopes that the findings of the study will encourage parents to have more engaging back-and-forths with their children. The researchers also note that while the scope of their study was limited to children 4 to 6 years of age, this type of conversational turn-taking can be done with younger children by taking turns making sounds back and forth.
Other scientists and educators have voiced their opinions on the study, generally supporting the study’s conclusions. Roberta Golinkoff (not involved in the study), an education professor at the University of Delaware School of Education,says the new study may have important implications for how parents and educators can assist children in developing strong language skills. Golinkoff says this study further supports the theory that just hearing words isn’t enough for language development.
“…If you’re not engaging with the child and having a conversational duet about what the child is interested in, you’re not going to give the child the language processing skills that they need,” says Golinkoff.
The MIT researchers are now aiming to study how possible techniques to promote conversational exchanges could be incorporated into children’s lives and what the possible effects of these techniques might be. These techniques may include assistance from technological devices such as electronic reminders for parents to engage in conversation with their children or computer programs capable of conversing.