Epidemiology in Military and Veteran Populations: Proceedings of the Second Biennial Conference, March 7, 1990

TABLE 1 HERITABILITY ESTIMATES FOR THE USE OF VARIOUS SUBSTANCES IN TWIN STUDIES FROM FINLAND, SWEDEN, AND THE UNITED STATES

			Heritability ^a
Study	Sample Size (Twin Pairs)	Country of Origin	Tobacco	Alcohol	Caffeine
Partanen et al. ³	902	Finland	0.28	0.47	0.46
Pedersen ⁴	137	Sweden	0.84	0.28	0.88
Kaprio et al. ²	5,044	Finland	0.46	0.51	0.46
Swan, Carmelli, et al. ²³ [NHLBI Twins]	360	USA	0.52	0.60
^a Proportion of total variance attributed to additive genetic effects. Note: Adapted from Hughes. ¹

TABLE 2 SUBSTANCE USE IN THE NAS-NRC AND FINNISH TWIN REGISTRIES