Behavioral Genetics Models

Dear Guinea-pig lovers,

Heritability is defined on the basis of phenotypic variance. One may regard a so-called common pathway model as a model that contains one or more latent phenotypes that mediate certain genetic and environmental effects on observed variables that function as indicators of those latent phenotypes. As a result the common pathway model enables us to calculate the heritability of both the mediating latent phenotype as well as the observed phenotypes.

Hello all,

I am really new in twin modeling as well as in R, therefore I would be very grateful if someone could advise me on a few issues regarding the script.

I am trying to run an ACE model with covariates (sex and age) on some twin height data. It would be very helpful to know whether the script (attached: test_height.R) does not have any major flaws and does what is expected of it. And one more thing, I would like to plot the residuals after performing the regression on the data. Could you please help me to find the most straight forward way to do that?

Anyone knows how to use OpenMx for twins study including non twins siblings, like family model?
Thanks

I would like to run a bivariate model for an ordinal variable and a continuous variable. The ordinal variable was measured in childhood and the continuous variable was measured in adulthood - therefore it makes sense that I should use a Cholesky decomposition testing whether the ACE influences on the ordinal (childhood) variable also influence the continuous (adulthood) variable. However in a liability threshold model for continuous and ordinal data, the ordinal variable should go last.