I'm trying to fit a saturated model to my data (1 binary variable, 5 zygosity groups), and want to estimate 10 thresholds (one for each twin in all zyg groups), and 5 twin correlations (1 per zyg group). The model runs, the right number of parameters are estimated and the estimations look good, but the number of observed statistics is 0, so I get a negative number of degrees of freedom... There are no error messages, and I've looked into different parts of the model, but can't find where it goes wrong. I hope you can help me with this, thanks in advance!
VU University Amsterdam