No Two Children Have the Same Parents
Some people ask, if human development depends largely on the external environment then why is it that siblings, even identical twins, have different emotional responses? One might become an addict or have behavioural difficulties while the other one does not. The answer is that no two children have the same environment and the same parents, because it is not the physicality of the parents that matters but their emotional states. For example, if the parents are stressed during one pregnancy as opposed to the other or their relationship alters or the financial situation changes, all of these will have an impact on the child's development. Moreover, human development has a recursive nature which means parents are also shaped by the children and in response to their temperament. Therefore, some difference in the parent-child relationships is inevitable and so, no two children can have the same parents.