| |
Abstract:
This paper investigates the development of the
ability to compute scalar implicatures (SIs) during language
comprehension. SIs arise in examples like 'Some professors
are rich' where the speaker's use of 'some' typically indicates
that s/he had reasons not to use a more informative term, e.g.,
'all'. 'Some professors are rich' therefore gives rise to
the implicature 'Not all professors are rich'.
Although very little is known about the
psychological status of SIs, recent studies suggest that (a) for
adults, SIs "seem to be virtually non-existent in syllogistic
reasoning tasks" (Newstead, 1995), and (b) that preschoolers do
not show sensitivity to SIs (Noveck, 2001). These
conclusions raise two important questions: (1) Are SIs
psychologically real?; (2) If so, what factors affect the way SIs
are computed during language comprehension?
We present here the results of two experiments
designed to address these questions. In the first
experiment, we tested a group of 30 adults and 30 5-year-olds on
three different scales, 'some/all', 'two/three' and
'start/finish'. In each case, subjects were presented with
short stories which satisfied the truth conditions of the
stronger term of each scale (i.e., 'all', 'three', and 'finish')
but were described by a puppet using the pragmatically
infelicitous weaker term of the scale (i.e., 'some', 'two', and
'start').
We found that while adults overwhelmingly rejected
the puppet's infelicitous statements (95% of the time on
average), children did so only 29% of the time. Moreover,
we found that while the rejection rates of adults did not
significantly differ across the three scales, children's
rejection rate on the 'two/three' scale was reliably higher than
on the 'some/all' and 'start/finish' scales (65% vs. 12.5% and
10% respectively, p<.01). In order to address question
(2), we trained a group of 30 5-year-olds to detect pragmatic
anomaly (e.g., 'This is a brown thing' used to refer to a dog)
and then tested them in the way described in Experiment 1.
This manipulation gave rise to significantly higher rejection
rates (52.5% vs. 12.5%; 90% vs. 65% and 47.5% vs. 10%, p
<.01).
We conclude that: (i) adults easily compute SIs
when the task is relevant; (ii) children's ability to compute SIs
is more fragile than that of adults; (iii) children, unlike
adults, do not treat all scalar terms alike; and (iv) children's
ability to compute SIs is affected by their awareness of the goal
of the task. Theoretical, methodological and developmental
implications are discussed.
|
