This isn't concerning OpenMx per se, but rather a general twin analysis question.
My variables are PC scores from a decomposition of shape data. Normally for one variable, you'd calculate an ICC for MZ and DZ groups to show if there is greater similarity for MZ's, prior to more formal modelling. My data needs to be analysed together instead of testing each variable/PC separately. Is there a multivariate equivalent of the ICC - ie something like partial least squares or canonical correlations?