Verbal and Non-Verbal Fluid Intelligence as Predictors of Vocabulary Knowledge

Vocabulary development seems to be the most significant and useful activity in any language class because learning the words of a language is undeniably an important part of a speaker’s command of that language. Therefore, teaching vocabulary is an essential component of standards-based curriculum alignment. In view of that, this study aimed to find out whether there is a significant relationship between Iranian intermediate EFL learners’ vocabulary knowledge and their verbal and non-verbal fluid intelligence. To this aim, 201 English language intermediate students were asked to fill out three questionnaires including Vocabulary Level Test, Visual-Spatial Reasoning Test as a non-verbal fluid intelligence test, and the Persian adaptation of Baddeley’s 3-minute grammatical reasoning test as a verbal fluid intelligence test. The results of the study’s hypothesized model showed that vocabulary knowledge is predicted by both verbal and non-verbal fluid intelligence significantly, and non-verbal fluid intelligence is shown to be the stronger predictor of vocabulary knowledge than verbal fluid intelligence. Moreover, the results indicated that there is a significant difference in the level of EFL students’ vocabulary knowledge between male and female students while there is no significant difference in students’ verbal and non-verbal fluid intelligence regarding their gender.