Table 1.
Overview of the behavioural and cognitive findings from the DDP family risk study.
| Findings |
||||||||
|---|---|---|---|---|---|---|---|---|
| Longitudinal predictor of readinga |
Longitudinal predictor of arithmetica |
|||||||
| Who | When | Variable | On its own | After controlling for arithmetic | On its own | After controlling for reading | Group differencesb | Support for MDM? |
| Child | Age 4 - not yet in school | Nonverbal IQc | ✓ | ✗ | ✓ | ✗ | FRD < FRND = C | ✗ |
| Verbal IQc | ✓ | ✓ | ✓ | ✗ | FRD < FRND < C | ✓ | ||
| End kindergarten (age 5–6) | Rapid namingd | ✓ | ✓ | ✓ | ✓ | FRD < FRND = C | ✗ | |
| Phonological awarenessd | ✓ | ✗ | ✓ | ✗ | FRD < FRND < C | ✓ | ||
| Letter knowledged | ✓ | ✓ | ✓ | ✗ | FRD < FRND = C | ✗ | ||
| End Grade 2 (age 8) | Rapid naminge | – | – | – | – | FRD < FRND = C | ✗ | |
| Phonological awarenesse | – | – | – | – | FRD < FRND < C | ✓ | ||
| Word-reading accuracye | – | – | – | – | FRD < FRND < C | ✓ | ||
| Word-reading fluencye | – | – | – | – | FRD < FRND < C | ✓ | ||
| Pseudoword-reading fluencye | – | – | – | – | FRD < FRND < C | ✓ | ||
| Spellinge | – | – | – | – | FRD < FRND < C | ✓ | ||
| Dyslexic parent | Rapid naminge | – | – | – | – | FRD < FRND (< C) | ✓ | |
| Nonword repetitione | – | – | – | – | FRD = FRND (< C) | ✗ | ||
| Word-reading fluencye | – | – | – | – | FRD < FRND (< C) | ✓ | ||
| Pseudoword-reading fluencye | – | – | – | – | FRD = FRND (< C) | ✗ | ||
| Spellinge | – | – | – | – | FRD = FRND (< C) | ✗ | ||
| Self-reported literacy difficultiesd | – | – | – | – | FRD = FRND (< C) | ✗ | ||
| Non-dyslexic parent | Self-reported literacy difficultiesd | – | – | – | – | FRD < FRND (= C) | ✓ | |
a
Reading = word-reading fluency, arithmetic = arithmetic fluency.
b
Dyslexia status was assessed using word-reading fluency at the end of Grade 2 or halfway Grade 3. Regarding the parents of the control children, the best-reading parent features in the non-dyslexic parent comparison, and the other in the dyslexic-parent comparisons.
c
Reported in van Bergen et al. (2014b).
d
Reported in van Bergen et al. (2014a).
e
Reported in van Bergen et al. (2012).
FRD = familial-risk dyslexia, FRND = familial-risk no-dyslexia, C = control, MDM = multiple deficit model.