Clocks, engines, and quarks--love, dreams, and genes. What makes development happen?

That psychological growth and maturation throughout the lifespan involve progressive linear processes is an implicit assumption of all models of development. Within psychoanalysis, a particular focus has been those processes that hinder forward development and manifest themselves as regressions or fixations or in character structure. However, the implicit assumption of progressive, linear development leaves unexplored the central question of what are the processes that govern developmental progressions. What makes psychological development happen in more or less predictable ways and yet allows for considerable individual variability? And are those developmental progressions inevitably forwardly progressive? Questions regarding what regulates and integrates development are relevant not only for understanding the normal building up of the internal world and of childhood psychopathology but also for those times of dramatic mental reorganization in adulthood surrounding events such as pregnancy and aging and for issues of psychological change during and after an analysis. Clinical material from analyses with a child and an adult and from interviews with four- to five-year-old children is used to explore individual fantasies of how development and change happens. The central role of internalization and object relations in regulating psychological development is emphasized.