Introduction
Many writers use the term ‘developmental’ mainly to refer to psychological events occurring in childhood (Bowlby, 1988; Rutter, 1988). There is, of course, a logical nexus between psychological and physical development so that it could be argued that they are active concurrently and therefore cease at the same time. The corollary to such a view, taken in the extreme, would have it that psychological change in adulthood represents a passive response to current inputs, the form of that response having been already determined by childhood experiences. This is a linear model of behavior, which would see the individual adult person's role in behavioral and psychological change as essentially passive. A developmental model, in contrast, seeks to view the behavioral and psychological response of the person themselves as a significant factor in influencing both their own state and their environment through homeostatic and adaptive mechanisms.
In a model which equates physical with psychological development, old age is likely to be viewed as a period of involution and decay, rather than one of continued development. Superficially there is no innate reason that old age should be seen as more than a period of deterioration.
Comfort (1965) suggested that an old person was like ‘a space probe that has been “designed” by selection to pass Mars, but that has no further built-in instructions once it has done so, and no components specifically produced to last longer than that.