1. This has been called a strong model of development; see Baltes, Reese, and Lipsitt (1980). Piaget, and later Kohlberg and others, have laid out strong-view criteria for human developmental stages (Kohlberg & Kramer, 1969).
2. The stages in this example may seem at first not to exemplify meaning. However, as Piaget (1954) points out, an infant makes sense of the world largely in terms of his or her own movements and raw sensation (the “sensory-motor stage”).
3. Our main source and inspiration for the neo-Piagetian approach in this paper is Robert Kegan (1982, 1994), whose ideas integrate current ideas in the field about mature adult development. Other compatible frameworks include those of Erikson (1963), Gilligan (1982), Kohlberg and ...