I would like to ask several questions related to the lectures on day 6.
For the lecture " [Biometrical Age-Based Latent Growth Curve Modeling].", there is one point in the last slide which stated that “REALLY IMPORTANT: Know difference between genetic variance estimate and heritability”, I would like to ask whether you could clarify the difference between genetic variance and heritability. I know the formula of heritability which is the proportion of the total phenotypic variance attributed by the genetic variance. What else dfferences do they have?
This question is about the variance and covariance. In LGC for example, we fit latent intercept and latent slope , and could obtain means and variance and covariance for both of them. So variance means that the intercept/slope varies among different individuals, and is there any criteria that we could use to determine how big the variance/covariance is or not? If the variance of intercept is 0.001, could we say that is no variation for the intercept of LGC among different individuals? Another thing is to confirm that, the means and variances of intercept and slope in LGC using SEM are fixed and random effects of intercept and slope in the mixed effect model, is that correct?
Really very nice lectures and thank you so much.