If twins come from the same source are they dependent or independent of each other?

Question

If twins come from the same source are they dependent or independent of each other?

Answer 1

I assume you mean "dependent" in the scientific sense, where a change in one variable implies a change in the other.  In this sense, twins are independent of each other.  Think of it this way: if one twin writes a particular essay on a given day or has a particular dream, does that make it more likely that the other twin will do the same?  Many correlations are observed between the behaviors of twins, but these stem from common causality (i.e. both twins are working with the same DNA and similar upbringing) rather then a dependence of one twin's behavior on the other's.