Table 3:

Comparison of Twins Discordant for Head Injury

	Monozygotic Discordant Twins (N=68 families)		Dizygotic Discordant Twins (N=52 families)
	Wave 1 Ages 9–10	Δ(Wave 5 – W1) Ages 19–20	Wave 1 Ages 9–10	Δ(Wave 5 – W1) Ages 19–20
	μ ± SD	μ (95% CI)	μ ± SD	μ (95% CI)
NoGo Errors
Head Injury Group
No Head Injury	44 ± 24	−33 (−40, −25)	45 ± 20	−27 (−34, −21)
Head Injury	41 ± 23	*−20 (−28, −13)	50 ± 23	−30 (−37, −24)
Reactive Aggression
Head Injury Group
No Head Injury	0.72 ± 0.33	−0.30 (−0.44, −0.15)	0.61 ± 0.35	−0.20 (−0.32, −0.08)
Head Injury	0.61 ± 0.26	−0.17 (−0.31, −0.03)	0.64 ± 0.34	−0.20 (−0.32, −0.07)
Proactive Aggression
Head Injury Group
No Head Injury	0.08 ± 0.11	−0.03 (−0.08, 0.02)	0.06 ± 0.12	−0.01 (−0.05, 0.03)
Head Injury	0.07 ± 0.13	−0.01 (−0.06, 0.04)	0.07 ± 0.12	−0.01 (−0.05, 0.03)

Note: Observed means and standard deviations presented.

μ=Mean, SD=Standard Deviation, CI=Confidence Interval

^*p-value < 0.05 for change from Wave 1 compared to No Head Injury Group.