THE DEVELOPMENT OF EXECUTIVE FUNCTION IN EARLY ...

for the construction of the concept of dimensions, and for subsequent analytical processing of values on those
dimensions. As Zelazo and Frye (1997) suggested, it is only by distancing themselves from discriminations
within a dimension and considering two or more dimensions in contradistinction that children are able to
conceptualize dimensions qua dimensions (see also Smith, 1989). This issue will be addressed further in
Chapter VI.
IV. STUDY 3: WHAT DO CHILDREN PERSEVERATE ON WHEN THEY PERSEVERATE?
INTRODUCTION AND SUMMARY
Study 1 indicated that memory per se does not appear to be the primary cause of 3- to 4-year-olds' difficulty
with the DCCS. Three-year-olds can use four rules to sort a series of cards when those rules are not in conflict.
In Experiment 2, this success was found even for bidimensional rules (two shape rules and two color rules), so
bidimensionality per se does not appear to be the problem either. Study 2 focused on cases where there was
conflict among rules, and found that 3- to 4-year-olds had difficulty using bidimensional rules even when only a
single pair of rules ("if red, then here; if rabbit, then there") was required. Taken together, the results of Studies
1 and 2 support the claims of the CCC theory that 3- to 4-year-olds are able to represent and use pairs of lowerorder
rules, at one level in a hierarchy, but have difficulty formulating and using a higher order rule. According
to CCC theory, it may be possible to formulate a higher order rule in many situations, but it is necessary to do
so when a single stimulus must be responded to in terms of more than one dimension. Under these
circumstances, 3- to 4-year-olds will have difficulty resolving conflict between incompatible rule pairs. Study 3
examined further what types of conflict pose problems for 3- to 4-year-olds by asking what it is that children are
perseverating on when they perseverate on the standard version of the DCCS.
The CCC theory predicts that when children perseverate, they are perseverating on specific lower order rules
(e.g., "If red, then here; if blue, then there") a prediction that may be referred to as the specific rules hypothesis.
Children select and use a pair of rules during the preswitch phase, these rules become activated, and this
activation persists into the postswitch phase (Marcovitch & Zelazo, 2000). In contrast, children who perseverate
could be attending to stimuli solely in terms of the first dimension (i.e., the dimension hypothesis). This type of
perseveration would seem to correspond to the attentional biases described by Zeaman and House (e.g., House,
1989; Zeaman & House, 1963), and would result in centration on a dimension regardless of the particular values
of that dimension.