The belief (rejected in
PARTheory) that human behavior is strictly ruleful, and that if the rules, mechanisms, or processes are fully understood, human behavior and development can be predicted with perfect fidelity. Mechanical model theories are typically stated in the at-least-implied form of invariants, constants, or absolutes. G. Stanley Hall's notions about the universality of adolescent stress, for example, illustrates this when he wrote about adolescence being universally and
inevitably a period of storm and stress. Freud's notion about the universality and
inevitability of the Oedipus complex (for the normal development of males) is a second illustration.
