Table 1

Twin correlations and heritabilities of best-fitting models for the DTT data with two categories (Model I) or the actual scores (Model II). rMZ, monozygotic twin correlation;rDZ, dizygotic twin correlation; h 2, heritability; 95% CI, 95% confidence interval.

ModelThresholdsrMZrDZh2(95% CI)
I ≤230.790.4680% (65–90%)
II≤15, actual score0.670.4471% (61–78%)