The threads consist of contributions from metaphor theory, attachment theory, neurobiology factors, non-linear dynamic systems theory and cognition. Other models of cognitive development include the mechanistic, the contextual and the psychometric, but here we shall concern ourselves only with the organismic model and an elaboration of the last phase and beyond. Piaget's overall aim seems to have been to describe the formal laws of logic for a particular form of self-regulation that allows for the goal of sustaining equilibration-maintaining mechanisms for the cognition system as a whole. In other words, So it seems simplistic to equate adolescent cognition with formal operational thought. Having said that, the data suggests that adolescent cognition is more mature than that which preceded it. Another significant contribution from the neurobiology of cognition relates to the concept of hot cognitions. Building on van Geert's work it occurs to me that the biotope metaphor has an additional use.