Erik Erikson's Development Sequence of Child Development.
I came across Erik Erikson's work with regard to child development today. In his book, Childhood and Society, Erikson finds that there are changing psychosocial conflicts at each stage of development. It looks a little bit too simplistic in development, but it sure is interesting to see the flow of growth and the physiological changes affect the psychological growth. Truth is, these are basic markers and more often than not, there are overlaps across the different age ranges. Human beings are way too complex to be streamlined into any one particular stage.
(Adapted from Erik Erikson's Childhood and Society, Norton, 1950)