Extract random effect variances from lme4 mer model object

Question

I have a mer object that has fixed and random effects. How do I extract the variance estimates for the random effects? Here is a simplified version of my question.

Answer 1

This answer is heavily based on that on @Ben Bolker's, but if people are new to this and want the values themselves, instead of just a printout of the values (as OP seems to have wanted), then you can extract the values as follows:

Convert the VarCorr object to a data frame.

re_dat = as.data.frame(VarCorr(study))

Then access each individual value:

int_vcov = re_dat[1,'vcov']
resid_vcov = re_dat[2,'vcov']

With this method (specifying rows and columns in the date frame you created) you can access whichever values you'd like.