Table 4.

Within-Pair Correlations for Age of Onset of Musical Training and Cross-Twin/Cross-Trait Correlations for Age of Onset of Musical Training and Musical Achievement

Correlation and group	r
Age of onset within pairs
Monozygotic male	.39 [.28, .48]
Monozygotic female	.55 [.48, .61]
Dizygotic male	.34 [.21, .46]
Dizygotic female	.35 [.24, .45]
Dizygotic opposite sex	.21 [.10, .32]
Total monozygotic	.49 [.43, .54]
Total dizygotic	.29 [.22, .35]
Age of onset and musical aptitude across twins
Total monozygotic	.14 [.09, .20]
Total dizygotic	.13 [.08, .19]
Age of onset and musical achievement across twins
Total monozygotic	.20 [.15, .25]
Total dizygotic	.17 [.12, .22]

Note: Values in brackets are 95% confidence intervals.