The concept of polymorphism in chemistry refers to the ability of a substance to exist in more than one form or crystal structure. Allotropy is a specific type of polymorphism that occurs in elements rather than compounds. Polymorphic forms emerge under varying conditions such as temperature and pressure, and each form is distinct in its intermolecular arrangement. However, polymorphic substances do not have an identical crystal shape, which is what distinguishes the different forms. Therefore, the statement that 'The crystal shape of polymorphic substances is identical to each other' is not true about polymorphism.