Derived from embryology by Heinz Werner (1890-1964), he describes it as follows: ” … that wherever development occurs it proceeds from a state of relative globally and lack of differentiation to a state of increasing differentiation, articulation and hierarchic integration.” [Werner, 1957, in Harris, D.B. (Ed.), The concept of development. Minnesota: University of Minnesota Press, p. 126]. The concept was intended to capture the nature of change not only during both ontogeny and phylogeny, but also in what Werner termed ethogenesis (cultural evolution), pathogenesis (pathological development), and microgenesis (change over real time). Perhaps because of this all-encompassing analogical approach, the principle failed to gain a foothold in the study of ontogenetic development in general and child development in particular.
See Analogy (as a trope), Cultural evolution, Differentiation (general), Individuation, Microgenetic method, Pathogenesis (or pathogeny), Principle, Principle of the integration and individuation of behavior