How Many Words Should A Child Know?

Comparing Estimates of Vocabulary Acquisition

Many estimates of vocabulary size exist, with variability being their one constant.  The difficulties inherent in measuring vocabulary size have not stopped multiple researchers from coming up with their own numbers, some of which I’ve summarized below.

 

Despite the almost inevitable variation, the studies that support these estimates have told us some important things, such as…

• School age language acquisition occurs primarily through incidental experience more than formal teaching.
• Word learning shifts from concrete and functional to abstract and unusual.  This shift occurs gradually from third grade through the high school years.
• Environment matters.  Extreme environments extremely matter. 

There are many more of these studies than even what I’ve listed, and while I’m not saying I’ve seen it happen, it is possible that people could cherry pick ones that most support the point trying to be made.  Also, there is no consensus among anyone really, of what exactly counts for a word in these studies.  Does examine, examines, examined, etc. count as different words or variations of the same word?  Ultimately the numbers themselves aren’t as important as are examining what’s possible and what’s actually occurring.  We know from these studies that it is possible to learn many, many words – at rates of up to 14 words a day according to at least two sources.  Methods of teaching vocabulary – such as teaching categories, word webs, and using reading to facilitate vocabulary acquisition – can be helpful, but ultimately nothing works like an enriched experience.

Keep reading for more information about the sources of these studies.

Honorable Mention Language Acquisition Studies

I couldn’t decide on just one more language acquisition study, like I initially wanted to, so I’ll simply give out a few honorable mentions.

Eric Lenneberg and the critical period hypothesis – In 1967 Eric Lennneberg released a widely influential book based on his research popularizing the notion that if language is not learned before an early age – usually estimated at 4 to 6 years – a child’s ability to learn any language becomes greatly compromised, or disappears altogether.  Though this research has been advocated for and debated against by linguistic giants such as Noam Chomsky and Steven Pinker, the evidence from Lenneberg and others is flimsy, draws extensively from widely divergent examples of feral children, and is largely theoretical.

Research hasn't proven this chimp knows what's you're thinking

Theory of Mind – Theory of Mind describes the ability to infer the mental states of others.  D.G. Premack and G. Woodruff initally espoused Theory of Mind in their seminal 1978 paper, “Does the Chimpanzee have a theory of mind?”  Research by Wimmer and Perner in 1983 used a famous false belief task to test study participants’ abilities to put themselves in others’ shoes.  Simon Baron-Cohen, Alan M. Leslie, and Uta Frith published research in 1985 suggesting that children with autism have deficits in theory of mind.  Research in this area has been widespread, divergent, and often theoretically powerful. 

Jean Piaget – The study of his own three children formed the basis for much of Piaget’s work.  Not strictly language, per se, but his view of language acquisition was extremely influential, while the middle ground belief (in terms of nature versus nurture) of cognition’s intertwining with language is probably closer to the truth than anything else currently out there.  Good info exists here and here.  This information is especially informative.

I can’t not mention Broca, Vygotsky, or Kegl’s study of Nicaraguan sign language.

High Fives… Language Acquisition Studies – “Wugs”

Over the next few days I will be describing some of what I feel are the language acquisition studies marked by their significance to both our current knowledge of language acquisition as well as historical impact upon subsequent research in the field.  Without any adieu, and with no particular order, here they are.

image from (http://jean.berko.gleason.googlepages.com/home)

Jean Berko Gleason’s “Wugs”  – 1958

Berko Gleason and colleagues presented pictures of imaginary creatures to children.  The pictures were given labels such as “wug,” made up by the researchers.  The children were then presented with varieties of the make believe creatures to test their ability to apply linguistic rules.  The famous example is “This is a wug.”  (1 wug)  “What are these?”  (More than one.)  Very young children had difficulty, but children by age 4 or 5 could usually label the plural “wugs,” and most importantly – could do it without ever having heard the word used before.  These sorts of pictures were also used to test other aspects of syntax acquisition, such as possessives and verbs.  The nativists have long used this as evidence that language is not memorized.  A shortened explanation of what I think is going on can be found here. 

List of Classic Child Development Studies

Over on PsyBlog is an excellent group of articles describing 10 crucial child development studies.  This list is laden with language acquisition.  Among the list are:

  Infant Memory Works From Very Early

  How Children Learn the Earth Isn’t Flat

  Infants Imitate Others When Only Weeks Old

  When Children Begin to Simulate Other Minds

  How Infants Start the Journey to the First Word

The signficance of language in these and other classic studies highlights the signficance of language in overall development.  This is a great list!