This article analyses research of theories and models of intelligence. It examines current developments in intelligence research, covering the formation of more complex and diverse intelligence theories. First, the article examines some of the widely used aptitude/intelligence tests include, such Stanford-Binet Intelligence Quotient, Wechsler Intelligence Scale for Children (WISCIV) and Woodcock Johnson Test of Cognitive Ability. Secondly, the article critiques the analysis of psychometric theories and cognitive-contextual theories of intelligence, and a corresponding trend in intelligence research to de-emphasise the use of standardized testing to measure intelligence. It is concluded that psychometric theories, as used in traditional IQ tests, measure only a small part of intelligence and ignore other parts, whereas cognitive-contextual theories of intelligence with reference to Vygotsky, Piaget, Guilford, Sternberg, and Gardner reveal both conceptual and methodological problems, not to mention ambiguities with definitions of the constructs themselves. As to the use of intelligence testing in schools and elsewhere, it has been argued that both the term intelligence and the notions of intelligence testing, by their nature of intended selection, exclusivity, distinction and cognitive stratification, tend to legitimate meritocracy.