Table 4.

Phenotypic and cross-twin-cross-trait (CTCT) correlations of conduct symptoms with tobacco, alcohol, and cannabis use (95% confidence intervals between brackets).

	Tobacco use	Alcohol use	Cannabis use
Phenotypic correlation males	0.25 (0.15; 0.35)	0.18 (0.08; 0.27)	0.29 (0.18; 0.40)
Phenotypic correlation females	0.35 (0.25; 0.45)	0.16 (0.06; 0.25)	0.33 (0.21; 0.44)
CTCT Monozygotic males	0.22 (0.10; 0.34)	0.21 (0.08; 0.34)	0.30 (0.16; 0.42)
CTCT Dizygotic males	0.22 (0.07; 0.37)	0.09 (−0.07; 0.25)	0.18 (0.00; 0.34)
CTCT Monozygotic females	0.32 (0.20; 0.43)	0.16 (0.04; 0.27)	0.37 (0.24; 0.50)
CTCT Dizygotic females	0.39 (0.24; 0.52)	0.15 (−0.01; 0.30)	0.39 (0.20; 0.55)
CTCT Dizygotic opposite-sex	0.20 (0.07; 0.32)	0.09 (−0.04; 0.21)	0.16 (0.02; 0.30)