Twins grieving more strongly for deceased co-twins seems to me explained by twins having a more closely coupled history than non-twin relatives. MZ twins grieving more strongly than DZ twins seems to me explained by MZ having larger similarity in personality so bonding more strongly due to that.
Twins grieving more strongly for deceased co-twins seems to me explained by twins having a more closely coupled history than non-twin relatives. MZ twins grieving more strongly than DZ twins seems to me explained by MZ having larger similarity in personality so bonding more strongly due to that.