Hi, sorry for the lack of clarity--it would be T = environmental component specific to twins, which can be obtained also if siblings are included in the analysis (as an extended analysis): https://doi.org/10.1093/cercor/bhaa254.
As a comment, note that variance that seems specific to twins because DZ twins correlate more than siblings could be due to age and cohort effects that decay the sibling correlation relative to the DZ twins. Even prenatally, maternal diet and stress likely differ more across pregnancies than it does across placentas in a twin pregnancy. That too could easily generate lower sib than DZ correlations. These processes seem inherently at least as likely as, e.g., people going "Ooooh they're twins, let's treat them really really similarly..." - this is especially difficult to do if you don't know a person is a twin :).
umxACEv
Hi: Not sure I understand what you are asking: What is the "twin variance component" to which you refer?
Log in or register to post comments
In reply to umxACEv by tbates
ACET model
Hi, sorry for the lack of clarity--it would be T = environmental component specific to twins, which can be obtained also if siblings are included in the analysis (as an extended analysis): https://doi.org/10.1093/cercor/bhaa254.
Log in or register to post comments
In reply to umxACEv by tbates
Might there be any insight
Might there be any insight into this, or would it be more appropriate to use openmx directly specifically for this question?
Log in or register to post comments
In reply to Might there be any insight by a_researcher
Beware of T
As a comment, note that variance that seems specific to twins because DZ twins correlate more than siblings could be due to age and cohort effects that decay the sibling correlation relative to the DZ twins. Even prenatally, maternal diet and stress likely differ more across pregnancies than it does across placentas in a twin pregnancy. That too could easily generate lower sib than DZ correlations. These processes seem inherently at least as likely as, e.g., people going "Ooooh they're twins, let's treat them really really similarly..." - this is especially difficult to do if you don't know a person is a twin :).
Log in or register to post comments