Variability in Early Communicative Development

Abstract

Data from parent reports on 1,803 children--derived from a normative study of the MacArthur Communicative Development Inventories (CDIs)--are used to describe the typical course and the extent of variability in major features of communicative development between 8 and 30 months of age. The two instruments, one designed for 8-16-month-old infants, the other for 16-30-month-old toddlers, are both reliable and valid, confirming the value of parent reports that are based on contemporary behavior and a recognition format. Growth trends are described for children scoring at the 10th-, 25th-, 50th-, 75th-, and 90th-percentile levels on receptive and expressive vocabulary, actions and gestures, and a number of aspects of morphology and syntax. Extensive variability exists in the rate of lexical, gestural, and grammatical development. The wide variability across children in the time of onset and course of acquisition of these skills challenges the meaningfulness of the concept of the modal child. At the same time, moderate to high intercorrelations are found among the different skills both concurrently and predictively (across a 6-month period). Sex differences consistently favor females; however, these are very small, typically accounting for 1%-2% of the variance. The effects of SES and birth order are even smaller within this age range. The inventories offer objective criteria for defining typicality and exceptionality, and their cost effectiveness facilitates the aggregation of large data sets needed to address many issues of contemporary theoretical interest. The present data also offer unusually detailed information on the course of development of individual lexical, gestural, and grammatical items and features. Adaptations of the CDIs to other languages have opened new possibilities for cross-linguistic explorations of sequence, rate, and variability of communicative development.

Vocabulary development in Greek children: a cross-linguistic comparison using the Language Development Survey*

“…Individual variation in early vocabulary has also been reported among children acquiring Spanish (Bornstein, Cote, Maital, Painter, Park & Pascual, 2004 ;Jackson-Maldonado, Thal, Marchman, Bates & Gutierrez-Clellen, 1993), Italian (Camaioni & Longobardi, 1995 ;Caselli et al, 1995), Hebrew (Maital, Dromi, Sagi & Bornstein, 2000) and Japanese (Tamis-LeMonda, Bornstein, Cyphers, Toda & Ogino, 1992). Gender differences in early lexical development have also been widely reported (Rescorla, 1989 ;Rescorla & Achenbach, 2002;Fenson, Dale, Reznick, Bates, Thal & Phethick, 1994), with girls typically having somewhat larger reported vocabularies than boys.…”

“…With respect to the composition of early lexicons, data from languages such as English, Hebrew and Italian (Benedict, 1979 ;Caselli et al, 1995 ;Dromi, 1987 ;Fenson et al, 1994 ;Rescorla, Alley & Book, 2001) reveal that early lexicons contain words from a variety of different semantic classes. For example, reported that the thirty-eight words present in the lexicons of at least 80 % of their sample at 2; 0 to 2;2 included animal names (' dog ', ' cat ', ' bird '), foods (' juice ', ' banana', ' cookie', 'apple '), toys (' ball ', ' book '), clothes (' shoes ', ' socks '), household items (' spoon ', 'bed ', ' cup ', ' key '), people ('mommy ', ' daddy ', ' baby ') and social words (' no ', ' byebye ', ' hi ', ' yes ', ' thank you ', ' please ').…”

“…For example, reported a q correlation of 0 . 86 between a Pennsylvania sample of 422 children and the children of comparable age from the Fenson et al (1994) norming sample for the CDI for the 280 words in common between the two checklists. When q correlations were calculated between the US national survey sample used in the present study and the Pennsylvania sample and CDI samples used by , the resulting q correlations were, respectively, 0 .…”

Semantics guide infants’ vowel learning: Computational and experimental evidence

“…We could not test this possibility directly at 8 months, but an opportunity came when some of our infants (N = 20; 10 girls; 12 consistent; 8 inconsistent) returned 10 months later to participate in one of our other studies. We were thus able to obtain parental estimates of these children's productive vocabulary scores at 18 months (Dutch version of the communicative-development inventory for toddlers (Fenson et al, 1994;Zink & Lejaegere, 2002). This sample of 20 was not significantly different from the larger set with regards to the number of trials they attended to during the training phase (t[47] = −0.787, p = 0.435; median number of attended trials = 108.5, SD = 15.9).…”

Learned Labels Shape Pre‐speech Infants’ Object Representations

“…Three‐dimensional stimuli are depicted in Figure 1 and consisted of two age‐appropriate wooden toy objects (castanets and two wooden balls joined with string), chosen because they are novel to ten‐month‐old infants (Fenson et al., 1994). Objects were approximately equal in size and were painted either red or blue using nontoxic paint.…”