The C-Test: An Integrative Measure of Crystallized Intelligence

Crystallized intelligence is a pivotal broad ability factor in the major theories of intelligence including the Cattell-Horn-Carroll (CHC) model, the three-stratum model, and the extended Gf-Gc (fluid intelligence-crystallized intelligence) model and is usually measured by means of vocabulary tests and other verbal tasks. In this paper the C-Test, a text completion test originally proposed as a test of general proficiency in a foreign language, is introduced as an integrative measure of crystallized intelligence. Based on the existing evidence in the literature, it is argued that the construct underlying the C-Test closely matches the abilities underlying the language component of crystallized intelligence, as defined in the well-established theories of intelligence. It is also suggested that by carefully selecting texts from pertinent knowledge domains, the factual knowledge component of crystallized intelligence could also be measured by the C-Test.