The first words arrive around the first year of life. Then the vocabulary expands, increasingly longer sentences appear, small monologues, and between the second and third year of life most children begin to speak. However, how long it takes to reach the goal is very subjective: some take very little, others an eternity, leaving parents to torment themselves for many months with the idea that something is not going as it should. Clearly, language development depends on many factors, some genetic, others environmental. But according to a study published in recent weeks in the Proceedings of the National Academy of Sciences, there is mainly one variable that allows us to predict how soon a child will start speaking: how often he hears the adults around him talking.
The research is the result of the work of Elika Bergelson, a Harvard psychology professor specializing in the study of language development during growth. And she was created to dispel some of the myths that circulate among experts on this topic, in particular that gender, the socioeconomic status of the family or exposure to a multilingual environment influence the speed with which children begin to speak.
To investigate the issue thoroughly, the American psychologist turned to the potential of artificial intelligence, which allowed her to study the first steps in the world of language of over a thousand children living in 12 different nations, and exposed to over 43 different languages .
Thanks to wearable recording devices, the researchers were able to monitor the children’s progress in real time and, at the same time, the linguistic environment that surrounded them, accumulating over 40 thousand hours of audio recordings at the end of the study. Too many to analyze manually, but nothing particularly challenging for an artificial intelligence. After providing the algorithm with recordings, information about the children and their families, the researchers were then able to test several hypotheses about the factors that influence how quickly language skills improve in the first years of life.
For the three hypotheses we mentioned previously (sex, socioeconomic conditions and multilingualism) no significant connection emerged with the number of words known and spoken daily by children. The age of the children, however, proved to be a key element, with an average of 66 more words per hour for each year of life. As well as the quantity of words spoken by adults in their presence: for every 100 words heard by children every hour, they produce on average 27 more. And for every year of a child’s life, this effect increases by an average of 16 more words spoken every hour.
“There has been a lot of discussion in the scientific literature in recent years about the influence that the socioeconomic status of the family can have on linguistic input and output,” explains Bergelson. “We have looked at this question from many, many angles, and in the tens of thousands of hours of recordings we have studied we have found no evidence that mothers with a higher level of education have children who talk more.” To maximize the chances that a child will start talking as soon as possible, all that remains is to commit to reading fairy tales to him and talking to him as much as possible. The rest will be done by time.