Select characteristics of twins from same-sex pairs enrolled in the University of Washington Twin Registry.

*<p>Indicates difference between monozygotic and dizygotic twin pairs at <i>P</i><0.05; data for cut-points presented as percentage achieving that standard; SD, standard deviation.</p

Univariate biometric genetic model for binary measures of physical activity in UWTR same-sex twin pairs.

*<p><i>ACE</i> refers to a model that includes additive genetics (A), common environment (C), and unique environment (E), <i>AE</i> only includes additive genetics and unique environment, and <i>CE</i> only includes common and unique environment;</p>†<p>Proportion of variance (and 95% confidence interval) due to additive genetics, shared environment, and unique environment factors according to each model;</p>‡<p>Akaike's information criterion (AIC) is a global measure of goodness of fit, with the best-fitting and most parsimonious models shown in bold.</p

Within-pair tetrachoric correlations and 95% confidence intervals for each binary activity measure in monozygotic (solid white bars) and dizygotic (hatched bars) twins.

<p>Within-pair tetrachoric correlations and 95% confidence intervals for each binary activity measure in monozygotic (solid white bars) and dizygotic (hatched bars) twins.</p