Table 3.
Full correlation matrix of covariates, predictors and outcomes
| PMLU | CTW | ACK | COM | YN | WH | IMI | EXP | Prop Resp | MSEL RL | MSEL EL | VABS RL | VABS EL | MCDI RL | MCDI EL | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Income | .452** | .224 | .278 | .219 | .100 | .204 | .125 | .295 | .073 | .127 | .142 | .259 | .373* | .291 | .323* |
| n | 42 | 42 | 42 | 42 | 42 | 42 | 42 | 42 | 42 | 34 | 34 | 43 | 43 | 40 | 40 |
| PMLU | .652** | .170 | .279 | .235 | .237 | .135 | .585** | .164 | .578** | .674** | .482** | .703** | .743** | .694** | |
| n | 49 | 49 | 49 | 49 | 49 | 49 | 49 | 49 | 38 | 38 | 47 | 47 | 41 | 41 | |
| CTW | − .094 | − .109 | .187 | .304* | .319* | .798** | .178 | .748** | .725** | .463** | .721** | .744** | .782** | ||
| n | 49 | 49 | 49 | 49 | 49 | 49 | 49 | 38 | 38 | 47 | 47 | 41 | 41 | ||
| ACK | .589** | .479** | .476** | − .101 | .058 | .480** | − .046 | − .077 | .054 | .060 | − .163 | − .081 | |||
| n | 49 | 49 | 49 | 49 | 49 | 49 | 38 | 38 | 47 | 47 | 41 | 41 | |||
| COM | .544** | .277 | .292* | .140 | .618** | .211 | .126 | .149 | .134 | − .020 | − .024 | ||||
| n | 49 | 49 | 49 | 49 | 49 | 38 | 38 | 47 | 47 | 41 | 41 | ||||
| YN | .643** | .283* | .334* | .626** | .292 | .340* | .259 | .268 | .124 | .198 | |||||
| n | 49 | 49 | 49 | 49 | 38 | 38 | 47 | 47 | 41 | 41 | |||||
| WH | .207 | .508** | .595** | .201 | .315 | .378** | .451** | .206 | .309* | ||||||
| n | 49 | 49 | 49 | 38 | 38 | 47 | 47 | 41 | 41 | ||||||
| IMI | .484** | .315* | .447** | .407* | .555** | .470** | .395* | .405** | |||||||
| n | 49 | 49 | 38 | 38 | 47 | 47 | 41 | 41 | |||||||
| EXP | .421** | .732** | .635** | .598** | .799** | .688** | .724** | ||||||||
| n | 49 | 38 | 38 | 47 | 47 | 41 | 41 | ||||||||
| Prop Resp. | .439** | .285 | .200 | .303* | .197 | .246 | |||||||||
| n | 38 | 38 | 47 | 47 | 41 | 41 | |||||||||
| MSEL RL | .831** | .551** | .780** | .813** | .827** | ||||||||||
| n | 40 | 39 | 39 | 36 | 36 | ||||||||||
| MSEL EL | .585** | .854** | .841** | .911** | |||||||||||
| n | 39 | 39 | 36 | 36 | |||||||||||
| VABS RL | .814** | .698** | .659** | ||||||||||||
| n | 50 | 44 | 44 | ||||||||||||
| VABS EL | .857** | .887** | |||||||||||||
| n | 44 | 44 | |||||||||||||
| MCDI RL | .926** | ||||||||||||||
| n | 44 |
PMLU parent mean length of utterance, CTW child total words, ACK acknowledgments, COM comments, YN yes/no questions, WH WH questions, IMI imitations, EXP expansions, Prop Resp proportionate responsiveness, MSEL RL Mullen Scales of Early Learning receptive language age equivalence, MSEL EL Mullen Scales of Early Learning expressive language age equivalence, VABS RL Vineland Adaptive Behaviour Scales receptive language age equivalence, VABS EL Vineland Adaptive Behaviour Scales expressive language age equivalence, MCDI RL MacArthur-Bates communicative development inventories receptive vocabulary, MCDI EL MacArthur-Bates communicative development inventories expressive vocabulary
*p < .05, **p < .001