that 1-year-olds simultaneously use basic terms (e.g., “kitty”) and adult terms (e.g.,tiger)
to apply to the same object and therefore are not yet using the principle of mutual
exclusivity. Nelson (1988) suggests that because much of the work on mutual exclusivity
has been performed with preschool children, it obscures the fact that this principle may
develop in the course of language acquisition and may be not present in early word
learning.
2.3.2.1.4 The principle of contrast
An alternative to mutual exclusivity is what Clark (1987) has called the principle of
contrast. Following Bolinger (1977), she argues that there are no synonymous forms in
natural language. In particular every word differs in meaning from every other word,
though in some cases (e.g., couch and sofa, cup and mug) the difference is very fine. If
children possess the principle of contrast, this could lead them to structure their lexicon
so as to avoid interpreting new words as synonymous with existing forms. According to
the principle, as words are acquired they will be differentiated or contrasted with existing
words, and children will assume that different words have different meanings.
A classic study by Carey (1978) involved an experimenter asking 3- and 4-year-old
children to “bring me the chromium tray, not the blue one” (the target tray was in fact
olive green and there were only two trays available). Children, successfully picked out the
tray with the unknown colour, and later on showed some knowledge of the meaning of
the unknown colour term. This paradigm involves what has been termed a process of
lexical contrast whereby children work out the properties of an unknown word by
contrasting it with another known word.
Dockrell and Campbell (1986) followed up this investigation and found that 3- and 4-year-
old children were successful in acquiring a new name for an unknown toy animal in these
conditions, but had more problems with acquiring colour terms. Further support for the
principle of lexical contrast comes from Waxman and Hatch’s (1992) study. In their
study three- and four- year olds produced multiple hierarchically related labels for
individual objects.
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