“There’s one preschooler that at 2 years old just talked and talked and talked, but another is the exact same age and barely says a word!”

“Am I going to give my child a language delay because I talk to them in Arabic at home, but they learn English at school?”

              These fears that teachers and parents of young children have are very common. To alleviate some of these worries it is important to understand that variability in different parts of our human experience, from cognitive ability to social interaction to artistic creativity, is huge. Variability means that everyone does not fit into the exact same box. The human mind is incredibly complex and no two are exactly alike. For our species, variability is the rule, and language development is no exception.

              At two years of age, children have a vocabulary with an average size of 300 words with a standard deviation of about 170 words. What this means is that a child could produce between 130 and 470 words and be within one standard deviation of the average, or what is fairly common and expected. That is a difference of 340 words. For a two-year-old, that can more than double one’s vocabulary from one end of the spectrum to the other. Yet, it is all within what could be expected for typically developing children. This immense variability in child vocabulary makes it difficult to predict language delays, simply because so much variability is normal. This can, however, be a comforting finding.

              Toddlers are still at the beginning of learning their native language(s) which means that variability between children will be much more apparent to the adults around them. Depending on a child’s input, their vocabulary may look much different than their peers. Just because one child is talkative by 2 years doesn’t necessarily mean another child who isn’t chatty has any issues with their language ability. Linguistic ability is also not completely defined by vocabulary size, which simply captures what words they can produce. The personality and comfort level of a child in an environment may change how talkative they are on a given day. A child with a larger vocabulary isn’t guaranteed to chatter away. Variability in the day to day speech of a toddler is affected by a wide variety of factors and does not dictate whether a child has a language delay.

              What language we learn can also introduce variability into what kinds of words we learn early in life. English-learning infants in their second year of life often go through what is called a word spurt that consists mostly of nouns. During this time, they are learning on average nine new words a day! On the other hand, in languages like Korean, children go through a word spurt that consists of more verbs than English-learners. Even in typically developing monolingual children, what words they know and the kinds of ideas they can express can be very different depending on the language they’re learning.

              These differences in early learned words are related to caregiver language input. Korean-speaking caregivers use about twice as many verbs as nouns compared to English-speaking caregivers in their speech to children. English-speaking caregivers speak about an equal amount of verbs and nouns to children. The variability in language input leads children to pick up different words at these early stages of cognitive development. Children across languages become competent users of full languages, but depending on what language you’re learning, your early language knowledge may vary extensively!

              Children who learn multiple languages at the same time—bilingual or multilingual children—contend with an additional kind of variability. These children are learning multiple sets of vocabulary and grammar rules. This input increases the work the child must do to become an adult-level speaker, as they need to do so for multiple languages. The end result of this language experience is bi- or multilingualism, but oftentimes, a child’s proficiency in any one language may at an early age fall behind their monolingual peers.

              The variability in this input can come with unexpected difficulties for the child; however, this variability is still to be celebrated. Despite worries parents and teachers may have, research on bilingual children shows that they are not at a disadvantage. If a child is becoming bilingual in Korean and Spanish, and you only measure their Spanish vocabulary, then their language ability could seem diminished compared to Spanish-monolingual children of the same age. The important thing to remember is that bilingual children have twice as much to learn, so their attention is necessarily distributed across those languages. As such, current practice in research is to measure their abilities in each of their languages and combine them to get a more complete picture. In doing so, research has found that they are at least on pace, if not ahead, of their monolingual peers when their vocabulary is looked at as a whole. Whether you or your child speak one language or four is simply another piece in the variation of human language ability.

              In sum, the fears that parents and teachers of toddlers and young children have related to language development are understandable. All of us who care for a young one’s development will want the best for them, and early treatment for language delays is important. However, what tends to be missing from the discussion is the massive variability in child language development. This variability can create differences in children that are hard to interpret outside of a clinical setting. What is key to remember is that the human range of “normal” in terms of language development is much broader than you might imagine, and encompasses the quiet toddlers and the talkative ones, monolingual and multilingual speech patterns, and many other aspects of variability.

 

Note:

For more information on bilingual development, I would like to refer you to Dr. Atagi’s articles here and here on the Psychology in Action blog discussing what it means to be bilingual and the benefits it can bring.

 

Citations

Europeans and their languages, a survey co-coordinated by the European Commission. (2012). Retrieved from http://ec.europa.eu/commfrontoffice/publicopinion/archives/ebs/ebs_386_en.pdf

Feldman, Dollaghan, Campbell, Kurs-Lasky, Janosky, and Paradise (2000) Measurement Properties of the MacArthur Communicative Development Inventories at Ages One and Two Years. Child Development 71(2), 310-22.

Fenson, Bates, Dale, Goodman, Reznick, and Thal (2000) Measuring Variability in Early Child Language: Don’t Shoot the Messenger. Child Development 71(2), 323-8.

Golinkoff, R. M., Hirsh-Pasek, K., Bailey, L. M., & Wenger, N. R. (1992). Children and Adults Use Lexical Principles to Learn New Nouns. Developmental Psychology, 28(1), 99–108.

Tomasello, M. & Merriman, W. E. (2014). Beyond names for things: young children’s acquisition of verbs. New York: Psychology Press.

Tucker, Richard G. (1999) A global perspective on bilingualism and bilingual education. Carnegie Mellon University Online Resources.

Umbel, Pearson, Fernandez, and Oller (1992) Measuring Bilingual Children’s Receptive Vocabularies. Child Development 63.