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Why
Youngsters Try To Do Impossible Things
New Study Provides Window Into Child’s Mind
May 14, 2004 --
When
you see a small child try to fit into or on top of a doll-sized
toy, you’re likely to laugh. That’s exactly what three
co-investigators of a new study initially did when their own toddlers
attempted to fit into a toy car, a miniature room and a doll’s
crib.
Based
on those personal observations, as well as their research as
developmental psychologists interested in how young children
understand symbols, the researchers
from the University of Virginia, Northwestern University and the University
of Illinois at Urbana-Champaign set out to understand why youngsters,
who actually
know better, could ever make such dramatic mistakes about scale.
Not
to worry, moms and dads. The study of 18- to 30-month-old children,
published
in the May 14 issue of the journal Science, found these kinds of errors — scale
errors — to be common in this age group. Videotapes show many participants
in the research seriously trying to slide down miniature slides, squeeze
into tiny toy cars and sit in dollhouse chairs.
The
children’s dramatic
failures to use size when interacting with familiar objects may reflect
immaturity in the interaction of two brain systems – one
for visual recognition of objects, the other for perception of object size,
said Judy DeLoache, Kenan Professor of Psychology, University of Virginia,
and lead
author of the study. “In scale errors, the usual seamless integration
between the two systems in the brain momentarily breaks down, and the size
of an object is not incorporated into a child’s decision to act on
it. However, once the action begins, children do use size information to
adjust their motor behavior,” she said.
In deciding to get into the miniature car, children ignore how small it
is, but then they accurately open its tiny door and aim their foot directly
at its impossibly
small opening. “There’s a dissociation between the use of size
for planning actions versus controlling those actions,” she said.
“Even
infants can discriminate the size of objects, so the question
is why children sometimes ignore the fact that the objects are
so small,” said
David Uttal, associate professor of psychology at Northwestern and a study
co-investigator.
The
provocative part of the answer to that question fits with theories
that implicate two neurally and functionally
distinct brain systems underlying
the use of visual
information. One brain area is involved in the visual recognition and
categorization of objects (“That’s a chair.”) and with planning
what to do with them (“I’m going to sit down.”). A different
area is involved in the perception of object size and in the use of visual
information to control
actions on objects.
“One
reason this is so interesting is that similar kinds of dissociations
occur in various neurological impairments in adults, but they have
rarely been studied in healthy young children,” said Karl
S. Rosengren, professor of psychology at the University of Illinois
at Urbana-Champaign and a study co-investigator.
The
study also suggests a failure of inhibitory control, implicating
immaturity of the prefrontal cortex. It is well established that
infants and young
children have great difficulty inhibiting inappropriate responses.
In the case of
scale errors, an action appropriate for one object is inappropriately
directed to
its replica.
The
Science study’s implications are important
for understanding both the perception-action dissociation in
behavior of normally developing young children
and the early development of inhibitory control. The precise
nature of the breakdowns and factors that influence their occurrence
will
be the focus of future research.
The
study of 54 children, 18 to 30 months old, was conducted at the
University of Virginia’s
Child Study Center (go to http://www.faculty.Virginia.edu/childstudycenter/ and click on “Current Projects” to
find video clips of the children in the study).
The
youngsters were given experience in a playroom with three large
objects followed by exposure
to miniature replicas that
were identical
except
for size. They were
observed interacting with an indoor slide they could walk
up and slide down, a child-sized chair they could sit in and
a
car they
could get
inside and,
with their feet, propel around the room. The children were
then taken for a walk,
and when they returned to the room, they found the miniature
replicas in place of the larger objects. If they did not
spontaneously interact
with
the replicas,
the experimenters drew their attention to them without commenting
on their size. From videotapes of the sessions, the investigators
identified
a total
of 40 scale
errors committed by 25 of the 54 children.
Scale
errors were coded whenever a child made a serious attempt to
perform on a
miniature object the same actions they had
done with
the large one.
Persistence in trying to carry out the impossible action,
such as trying repeatedly to
squeeze
a foot through a tiny car door, was a particularly clear
sign of serious intent. Scale errors were clearly distinguishable
from
pretend play
with the objects. Contact:
Fariss Samarrai, (434) 924-3778 |