THE DEVELOPMENT OF EXECUTIVE FUNCTION IN EARLY ...

were similar in that children were told a total of four rules, two for sorting by color and two for sorting by
shape. In addition, in both versions, children were asked to switch from using two rules for sorting by one
dimension to using two rules for sorting by the other. However, a key difference between the versions may be
that in the 2+2-Rules (bidimensional, no overlap) version, any particular test card did not need to be treated
differently depending on the game being played. That is, there was no conflict among the rules. This issue is
addressed further in Study 2.
EXPERIMENT 3
In Experiments 1 and 2, the new versions all required children to sort a homogeneous series of test cards
according to one dimension or another. Moreover, there were only one or two relevant dimensions (shape or
color). It is possible, therefore, that these versions allowed children to chunk the information that they were
required to remember, thereby reducing the demands on memory. Although it seems unlikely that the
memory demands in the 2+2-Rules (bidimensional, no overlap) version were lower than those in the standard
version, Experiment 3 was conducted to address the question of memory limitations further, and in a different
way.
In Experiment 3, children were presented with a new version of the DCCS, the 4-Rules (superordinate) version,
in which they were required to sort a relatively heterogeneous series of test cards according to four discrete
superordinate categories. It was expected that the 4-Rules (superordinate) version would pose even greater
memory demands than the new versions used in Experiments 1 and 2, and that children would not only need to
remember the relevant rules but also make relatively difficult inferences to determine which rule was most
appropriate for each test card. That is, in addition to a storage component, there was also a considerable
processing component. Nonetheless, according to CCC theory, 3- to 4-year-olds should perform better on the
4- Rules (superordinate) version than on the standard version of the DCCS because only the standard version of
the DCCS requires the construction of a higher order rule.
Method
Participants. Twenty 3- to 4-year-olds (M = 41.5 months; range: 37 to 47 months; 9 girls and 11 boys) were
recruited in the same fashion as in Experiment 1. An additional 3 children were tested but excluded from the
final sample because they refused to complete the experiment (n = 1) or because of experimenter error (n = 2).
Procedure. Each child received the standard version of the DCCS and a 4-Rules (superordinate) version, with
half the children receiving the standard version first, and half receiving the 4-Rules (superordinate) version first.
The standard version was exactly like the standard version in Experiment 1, except that on each trial, the
experimenter labeled each test card by the relevant dimension only (e.g., "Here's a flower"). A yellow flower
and a green boat were used as target cards, and green flowers and yellow boats were used as test cards.
Dimension order was counter- balanced such that roughly half of the children within each version order were
first told to sort by color.
As in the 4-Rules versions used in Experiments 1 and 2, children in the 4-Rules (superordinate) version of the
DCCS were shown four target cards and told four rules for sorting test cards. Target cards and test cards are
shown in Table 2.
The experimenter described each target card in terms of the functional, superordinate categories cited in the
rules (i.e., things that can walk, things you can wear, things you can ride, and things you can eat). Then the
experimenter pointed to each target card in turn and said, "Now we're going to play a card game. In this game,
we put all the things that can walk over here [points to the dog]. If it is something that can walk, put it in this
box. We put all the things you can wear over here [points to the sweater]. If it is something you can wear, put it
in this box. We put all the things you can ride over here [points to the bus]. If it is something you
can ride, put it in this box. We put all the things you can eat over here [points to the apple]. If it is something
to eat, put it in this box."