Observed correlations
The “Symmetric” model provides estimates of correlations, as estimated
for MZ and DZ independently, and as all twins together (Table 2).
Table 2 present observed maximum likelihood correlations. Most
rph correlations were statistically significantly
different from 0, and about the same magnitude in both the MZ and DZ
twins (except for the correlation between eosinophils and asthma which
was 0.29 and significant in MZ twins but was –0.05 and non-significant
in DZ twins), indicating that all variables are associated within
individuals. All ICCs were statistically significantly different from 0
and higher in the MZ twins than in the DZ twins, indicating a heritable
component for the univariate measures. All CTCTs had a higher magnitude
in the MZ twins than in the DZ twins indicating that genes affect the
association between all variables.