On the nature of crystallized intelligence: the relationship between verbal ability and factual knowledge

The C-Test: An Integrative Measure of Crystallized Intelligence

“…Vocabulary tests are very commonly used to measure Gc because they are related both to verbal abilities and factual knowledge. "Knowledge of word meanings is declarative knowledge and tests of lexical knowledge are typically not limited to specific content domains, but vocabulary is also indispensable for any form of verbal communication and an important indicator of language development" [12] (p.159).…”

“…Gc is usually measured by means of vocabulary tests and other verbal tasks [11,12]. The purpose of this research is to introduce and suggest an integrative verbal task, namely the C-Test, as a valid and economic measure of the verbal component of Gc.…”

“…Although Gc is a recognized component of intelligence, it is not well understood and there is no agreement on its nature and content [12]. Whereas the original definition of the construct by Cattell [13,14] was very broad and contained knowledge and skills in many domains, Carroll's [2] model only included language abilities.…”

“…Carroll [2] states that whether you want to call Gc crystallized intelligence or verbal intelligence is a matter of choice. Major intelligence batteries define and test Gc differently but mostly focus on verbal ability measures [12].…”

“…Schipoliwski et al, [12] argue that Gc includes factual knowledge and should not be tested only with verbal indicators. They empirically show that, although verbal ability and factual knowledge are highly correlated, they are factorially distinct and form separate components of Gc.…”