Table 3.

Twin intraclass correlations and univariate h², c² and e² estimates for SWAN, DBD, ECS, FAIR and FCAT scores.

Variable	Twin intra-class correlations		Univariate estimates
	MZ	DZ	h2[C.I]	c2[C.I]	e2[C.I]
SWAN Inatta	.86*	.57*	.63†[.45–.85]	.21[.00–.40]	.16† [.13–.19]
SWAN Hypb	.94*	.68*	.49† [.37–.64]	.43† [.26–.60]	.08† [.06–.10]
DBD Inattc	.81*	.48*	.83† [.61–.98]	.02[.00–.23]	.18† [.14–.22]
DBD Hypd	.87*	.52*	.81† [.62–1.03]	.11[.00–.31]	.14† [.12–.18]
ECS Parente	.86*	.68*	.57† [.41–.77]	.31† [.11–.51]	.14† [.11–.17]
ECS Selff	.39*	.48*	.01[.00–.40]	.42† [.10–.58]	.57† [.45–.69]
FAIRg	.67*	.45*	.52† [.37–.67]	.14† [.02–.27]	.34† [.29–.39]
FCATh	.75*	.49*	.55† [.43–.68]	.20† [.09–.30]	.25† [.22–.29]

^*p < .05 for intraclass correlations.

^†significant univariate estimate based on 95% confidence intervals not bounding zero.

^aSWAN Inattention.

^bSWAN Hyperactivity/Impulsivity.

^cDBD Inattention.

^dDBD Hyperactivity/Impulsivity.

^eEffortful Control Scale (ECS) Parent-report.

^fEffortful Control Scale (ECS) Self-report.

^gFAIR Reading Comprehension.

^hFCAT Reading (FCAT).