I found the class discussion about twins and the simalirity/differences in their behavior to be rather interesting. Afer reading some braod articles about the behavior of twins, and the genetic make up of twins I have put together some thoughts about why identical twins would behave differently to the same input despite their identical genetic make-up.

While the twins may have the same genetic make-up, and have shared manyof the same enviromental influences such as family upbrining, there have still been many different influences in the lives of twins such as their peer groups. So while the genetic make-up may be identical/similar different genes may have developed in one rather than the other.

Behavior is not coded for by one gene in the genetic make-up but is a polygenic trait. So while twins may have the same genetic make-up their behavior will be different based on whcih of the genes are activated etc.

When there is an input from the outside world, the behavior/output of identical twins will differ based on their experiences and the development of certain traits or genes in their identical genetic make-up.