Parental Educational Level, Language Characteristics, and Children Who Are Late to Talk Celeste Domsch Department of Hearing & Speech Sciences Vanderbilt University Ph.D. Final Oral Defense March 12, 2003

Purpose To examine parental education and language in relationship to language development in children who are late to talk

Identifying Children Who Are Late to Talk (CWLT) Normal hearing Normal nonverbal intelligence Do not have autism or other neurological disorders Are not bilingual Score in bottom 10 th percentile for expressive vocabulary

Hypotheses tested: 1.That parental educational level was positively associated with parental language measures; 2.That parental educational level was positively associated with child language measures; 3.That parental language use was positively associated with child language development

Method 20 participants (20 CWLT and their parents) –CWLT 16 male (two of 16 were twins), 4 female Mean age = 29.9 months, SD = 4.1 Mean nonverbal IQ = 103.6, SD = 9.3 Mean vocabulary size = 70.3 words, SD = CWLT in speech/language treatment

Method Parents (19 sets; one family had twins) –Mean maternal education = years, SD = 2.36 –Range = 12 to 19 years –Mean paternal education = years, SD = 2.47 –Range = 12 to 19 years –15 families intact, 3 divorced and remarried, 1 never married –Mother was primary caretaker for 18 CWLT; father was primary caretaker for remaining 2 CWLT

Method Procedures –Each family received 5-7 home visits over 8-months Parent completed vocabulary checklist Experimenter collected language sample –Parent playing with CWLT for 15 min. –Videotaped Experimenter tested receptive and expressive language on final visit

Method Main Dependent Measures –Parents Years of education from questionnaire Mean length of utterance (MLU) from language sample Total number of words (TNW) from language sample Number of different words (NDW) from language sample –CWLT Vocabulary size in words from parent checklist MLU from language sample TNW from language sample NDW from language sample Receptive vocabulary test score Expressive vocabulary test score Data Analyses –Pearson product-moment correlations –Hierarchical Linear Modeling

Results Testing H1: that parents with more education talked more to their CWLT Are parental educational levels positively associated with parent MLU, TNW, or NDW? Parental education not correlated with parent MLU, TNW or NDW; however, parent MLU, TNW and NDW all correlated with one another (p <.05)

Results Testing H2: that more educated parents had CWLT who were more verbal Is parental educational level positively associated with child MLU, TNW, or NDW? Neither child TNW nor NDW was correlated with parental educational level; however, child MLU was correlated with parental educational level (r =.445, p <.05)

Results Testing H2: that more educated parents had CWLT who were more verbal Is parental educational level positively associated with child language test scores? Parental educational level was not correlated with either child receptive or expressive vocabulary scores Interestingly, 9 CWLT scored in the normal range for both receptive and expressive vocabulary 8- months after intake; 5 remained delayed in both

Results Testing H3: that parents who talked more had CWLT who were more verbal themselves Are parental language measures (e.g., MLU, TNW, NDW) positively associated with child language test scores? Neither Parent MLU nor TNW was correlated with Child receptive or expressive scores Parent NDW was correlated with receptive language (r =.55, p <.05), but not with expressive language

Hierarchical Linear Modeling (HLM) Used to analyze changes in children’s language over time (sampled 5-7 times over 8-months) Level-1 model tested whether individual CWLT differed from one another in their initial status and rate of growth for various language measures Level-2 model tested whether selected parent factors were significant predictors of growth

HLM Questions Is parental educational level positively associated with child vocabulary growth? Is initial parental MLU positively associated with growth in child MLU? Is initial parental TNW positively associated with growth in child TNW? Is initial parental NDW positively associated with growth in child NDW?

HLM Results CWLT varied significantly in their initial status and rate of growth for all measures (vocabulary size, MLU, TNW, NDW) But selected parent factors (parental education, MLU, TNW, NDW respectively) did not predict growth That is, parents with more education, or who used more total words, a greater variety of words, or longer sentences, did not have late talkers who showed faster language growth

Discussion Parental education was positively correlated with child MLU Parental NDW was positively correlated with child receptive language test scores CWLT varied significantly in initial status and rate of growth for vocabulary size, MLU, TNW, and NDW But these variations were not apparently related to parental education or parental MLU, TNW, or NDW respectively

Conclusions CWLT appear to pay attention to, and benefit from, hearing a variety of words, even if they do not immediately produce them Parental educational level was not a reliable predictor of rich language input to CWLT Parental educational level also had no apparent effect on vocabulary growth or measures of child language (except MLU) Thus, lower levels of parental education did not constitute an additional risk factor for slowed language development in CWLT

Future Directions Include an even more diverse group of parents (i.e., non-high-school graduates) Compare results from optimal vs. typical language sampling techniques Group CWLT by severity of expressive delay (bottom 5 th percentile vs. bottom 10 th )