Table 1.
Descriptive statistics for the 29 individual difference variables and the two comprehension measures.
| Variables | N | Minimum | Maximum | Mean | Standard Deviation |
|---|---|---|---|---|---|
| Decoding & Phono. Awareness | |||||
| Orthographic Decision (ms) | 261 | 523.207 | 157.653 | 762.638 | 141.630 |
| Phonological Decision (ms) | 252 | 1157.615 | 8084.414 | 2659.039 | 1106.412 |
| Non-word Naming (ms) | 243 | 139.750 | 6479.044 | 1053.328 | 483.228 |
| Phoneme Transposition* | 224 | 0.040 | 1.000 | 0..876 | 0.131 |
| Working-Memory Capacity | |||||
| Reading Span* | 285 | 0.270 | 0.930 | 0.640 | 0.135 |
| Alphabet Span* | 284 | 0.130 | 0.970 | 0.733 | 0.121 |
| Minus Span* | 281 | 0.100 | 1.000 | 0.834 | 0.136 |
| Visual Number Span* | 278 | 0.000 | 0.710 | 0.345 | 0.073 |
| Suppression/Inhibition | |||||
| Go-No-Go* | 256 | 0.000 | 0.700 | 0.138 | 0.136 |
| Stroop Interference (ms) | 245 | −257.809 | 1052.417 | 96.981 | 102.886 |
| Print Exp. & Background Know. | |||||
| Author Recognition Test* | 279 | 0.000 | 0.500 | 0.175 | 0.104 |
| Reading Questionnaire | 330 | 1.000 | 5.000 | 3.580 | 0.962 |
| Cultural Intelligence* | 262 | 0.120 | 0.910 | 0.573 | 0.138 |
| Scientist Recognition Test* | 279 | 0.000 | 0.640 | 0.247 | 0.109 |
| Vocabulary | |||||
| Extended Range Vocabulary* | 278 | −0.090 | 0.720 | 0.319 | 0.148 |
| Advanced Vocabulary* | 270 | 0.000 | 0.690 | 0.345 | 0.143 |
| Nelson-Denny Vocabulary* | 283 | 0.630 | 0.980 | 0.866 | 0.079 |
| General Reasoning | |||||
| Raven’s Progressive Matrices* | 280 | 0.290 | 1.000 | 0.723 | 0.129 |
| Arithmetic Aptitude Test* | 278 | 0.070 | 0.990 | 0.498 | 0.194 |
| Mathematic Aptitude Test* | 261 | −0.150 | 0.960 | 0.366 | 0.154 |
| Necessary Arithmetic Ops.* | 274 | −0.040 | 0.960 | 0.516 | 0.179 |
| Perceptual Speed | |||||
| Letter Comparison* | 274 | 0.040 | 0.740 | 0.191 | 0.054 |
| Finding As* | 274 | 0.080 | 0.690 | 0.312 | 0.083 |
| Number Comparison* | 275 | 0.100 | 0.530 | 0.284 | 0.063 |
| Pattern Comparison* | 262 | 0.570 | 1.000 | 0.962 | 0.061 |
| Identical Pictures* | 260 | 0.320 | 1.000 | 0.707 | 0.138 |
| Verbal Fluency | |||||
| Word Beginnings | 276 | 9.000 | 57.000 | 26.360 | 7.916 |
| Word Endings | 262 | 4.000 | 53.000 | 31.500 | 8.128 |
| Word Beginnings & Endings | 277 | 0.000 | 58.000 | 19.230 | 6.944 |
| Comprehension | |||||
| Nelson-Denny* | 263 | 0.222 | 1.000 | 0.788 | 0.157 |
| Investigator-Generated* | 303 | 0.460 | 0.922 | 0.773 | 0.091 |
*
reported as proportions