Recursion Through Dictionary Definition Space: Concrete Versus Abstract Words

At least a subset of our vocabulary must be grounded in the sensorimotor world for the words to have meaning in our minds. Analysing definitions recursively in dictionaries which use a fixed vocabulary to define all their words can give some idea of how new meanings can be grounded in terms of already grounded ones. Concrete words should be easier to ground than abstract ones, because sensorimotor contact with their referents is more direct. Human participants rated the degree of abstractness of word-pairs from the controlled vocabularies of two dictionaries. The fixed defining vocabularies of both dictionaries were found to have more abstract words than concrete ones, according to these ratings. The abstract words had longer definitions and their recursive paths through definitional space encompassed more words, compared to concrete words. The results suggest that although the definitions of concrete words are shorter and more direct, abstract words are more widely used in grounding definitions.