Table 1.

Correlations Between Original Reading Composite and Other Cognitive Measures

Phenotype	Reading compositea
NC English
Speaking and listening	.632**
Reading	.937**
Writing	.691**
English composite	.859**
NC math
Using and applying	.612**
Numbers and algebra	.630**
Shapes, space, and measures	.631**
Math composite	.665**
General cognitive ability
Vocabulary	.386**
Similarities	.328**
Conceptual Grouping	.180**
Picture Completion	.156**
Verbal Composite	.410**
Nonverbal Composite	.224**
Composite g	.397**

Note.NC = National Curriculum.

^aThis reading composite is described in Meaburn et al. (in press) and is a composite score of the Twins Early Development Study NC reading measure and the Test of Word Reading Efficiency. This composite was used in the original association study that identified the 10 single nucleotide polymorphisms associated with reading ability.

^**indicates significance at .01 alpha level.