. Author manuscript; available in PMC: 2013 Sep 1.

Published in final edited form as: Behav Genet. 2012 Jul 18;42(5):764–777. doi: 10.1007/s10519-012-9551-0

Table II.

Phenotypic, Cross-twin within-trait, and cross-twin cross-trait correlations

	14 months				20 months				24 months				36 months

	Obs-t1	Parent-t1	Obs-t2	Parent-t2	Obs-t1	Parent-t1	Obs-t2	Parent-t2	Obs-t1	Parent-t1	Obs-t2	Parent-t2	Obs-t1	Parent-t1	Obs-t2	Parent-t2

MZF
Obs-t1	1.0				1.0				1.0				1.0
Parent-t1	0.41^**	1.0			0.49^**	1.0			0.49^**	1.0			0.50^**	1.0
Obs-t2	0.52^**	0.35^**	1.0		0.65^**	0.37^**	1.0		0.69^**	0.45^**	1.0		0.70^**	0.46^**	1.0
Parent-t2	0.35^**	0.48^**	0.41^**	1.0	0.37^**	0.58^**	0.49^**	1.0	0.45^**	0.59^**	0.49^**	1.0	0.46^**	0.60^**	0.50^**	1.0

DZF
Obs-t1	1.0				1.0				1.0				1.0
Parent-t1	0.41^**	1.0			0.49^**	1.0			0.49^**	1.0			0.50^**	1.0
Obs-t2	0.40^**	0.07	1.0		0.50^**	0.15^**	1.0		0.46^**	0.19^**	1.0		0.56^**	0.15	1.0
Parent-t2	0.07	−0.13^*	0.41^**	1.0	0.15^**	−0.06	0.49^**	1.0	0.19^**	0.07	0.49^**	1.0	0.15	−0.02	0.50^**	1.0

MZM
Obs-t1	1.0				1.0				1.0				1.0
Parent-t1	0.44^**	1.0			0.47^**	1.0			0.46^**	1.0			0.41^**	1.0
Obs-t2	0.55^**	0.38^**	1.0		0.61^**	0.36^**	1.0		0.71^**	0.42^**	1.0		0.49^**	0.30^**	1.0
Parent-t2	0.38^**	0.52^**	0.44^**	1.0	0.36^**	0.58^**	0.47^**	1.0	0.42^**	0.51^**	0.46^**	1.0	0.30^**	0.61^**	0.41^**	1.0

DZM
Obs-t1	1.0				1.0				1.0				1.0
Parent-t1	0.44^**	1.0			0.47^**	1.0			0.46^**	1.0			0.41^**	1.0
Obs-t2	0.43^**	0.08	1.0		0.47^**	0.15^**	1.0		0.48^**	0.18^**	1.0		0.21^*	0.06	1.0
Parent-t2	0.08	−0.14^*	0.44^**	1.0	0.15^**	−0.06	0.47^**	1.0	0.18^**	0.06	0.46^**	1.0	0.06	−0.02	0.41^**	1.0

Note:

indicates a significant p value of <.05;

^**

indicates a significant p value of <.01.

Obs-t1 = Observational factor, twin 1. Parent-t1 = Parent rating factor, twin 1. Obs-t2 = Observational factor, twin 2. Parent-t2 = Parent rating factor, twin 2.

MZF = monozygotic female group. DZF = dizygotic female group. MZM = monozygotic male group. DZM = dizygotic male group.