I think that one of the basic differences between both Macon and Sarah is how they see and view the issue of grief. Both of them experience this with the loss of the child, but I think that Macon views it as a much more private experience. Already predisposed to being introverted or pulling away from the world, Macon does not see grief as something to share, something that should leave the realm of the interior. Rather, it must remain within. This privatized notion of grief is vastly different from Sarah, who is afraid that she is moving into the realm that Macon occupies. Sarah believes that grief has to be shared, and that it must be public, to an extent. In Sarah's mind, the grieving process is one that she should be able to share with Macon. When she recognizes that Macon is incapable of doing so, it is in this respect where she departs from him. Macon is one that cannot bring himself to emotionally "clutter" himself with a public demonstration of grief. It would go against his penchant for order and for structure, something that Sarah has slightly repudiated with the death of Ethan.
Thank you !!!