Question

What are the rich and lean perspectives in developmental psychology ? Why does this "rich vs lean" debate exist ? How can it be resolved ?

Answer 1

We might expect that the parent’s role would be greater from the lean perspective—there is, after all, less knowledge yet in place through much of infancy, and thus more that still needs to be developed, if we adopt a lean interpretation of infants’ abilities. On the other hand, the rich perspective hardly denies a role for experience, including an important role for parents, in children’s development. Although theorists under this heading may offer a more positive conception of infant abilities than do those working under the lean heading, none believes that abilities emerge automatically and in full form; rather, any ability has a developmental history and a typical time of emergence (and indeed, theorists in the rich tradition differ among themselves with respect to when particular competencies develop). Furthermore, some theorists under the rich heading (Legerstee and Tomasello in particular) are strong proponents of the sociocultural approach to theory of mind, and thus of a maximal role for experience in general and for experience with parents in particular. Parents, then, can be important under either a rich or a lean perspective; again, the differences concern not whether but when and how.

A rich interpretation imputes a good deal of underlying, interrelated knowledge in its attempts to explain overt behavior—in the present case, either an adult-like or close to adult-like understanding of the psychological states that underlie acts of joint attention.