Answer to Question 1
Continuity implies that developmental changes are gradual and quantitative (i.e., expressed as amounts that can be measured numerically, such as weight and height changes) and that future behavior patterns can be predicted from earlier patterns. Discontinuity, in contrast, implies that developmental changes are abrupt and qualitative (i.e., expressed as qualities that cannot be measured numerically, such as changes in mood or expression) and that future behavior is poorly predicted by earlier patterns.
Answer to Question 2
Our first underlying assumption is that abnormal child behavior is multiply determined. Thus, we have to look beyond the child's current symptoms and consider developmental pathways and interacting events that, over time, contribute to the expression of a particular disorder. Our second assumption extends the influence of multiple causes by stressing how the child and environment are interdependenthow they influence each other. This concept departs from the tradition of viewing the environment as acting on the child to cause changes in development, and instead argues that children also influence their own environment. In simple terms, the concept of interdependence appreciates how nature and nurture work together and are, in fact, interconnected. Few psychological disorders or impairments suddenly emerge without at least some warning signs or connections to earlier developmental issues. This connection is apparent, for example, in early-onset and persistent conduct disorders, with which parents and other adults often see troublesome behaviors at a young age that continue in some form into adolescence and adulthood.