Parent Education, Language Characteristics, and Children Who Are Late to Talk Celeste Domsch, Ph.D. Baylor University Stephen Camarata, Ph.D. Edward G. Conture, Ph.D. Vanderbilt University ASHA Annual Convention 2003 Chicago, Illinois
Acknowledgements This research was funded in part by a grant to the first author from the Bamford-Lahey Children’s Foundation. Thanks also to the parents and children who participated in the study.
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 10th percentile for expressive vocabulary on the MacArthur CDI
Hypotheses tested: • 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 = 52.8 • 11 CWLT in speech/language treatment
Method • Parents (19 sets; one family had twins) • Mean maternal education = 14.42 years, SD = 2.36 • Range = 12 to 19 years • Mean paternal education = 14.32 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 (CDI) • Experimenter collected language sample • Parent playing with CWLT for 15 min. • Toys provided by experimenter • Videotaped • Experimenter tested receptive and expressive language on final visit using the PPVT-III and EOWPVT-R
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 (CDI) • 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; 6 were delayed in one domain only
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 the 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 in this study
Future Directions • Include an even more diverse group ofparents (i.e., non-high-school graduates) • Compare results from optimal vs. typical language sampling techniques • Group CWLT by severity of expressive delay (bottom 5th percentile vs. bottom 10th) • Follow-up these 20 CWLT after kindergarten to observe longer-term outcomes • These slides are available at www.domsch.com.