The multiple factor theories have expanded the view of intelligence to embrace major group factors as well as (g) itself. Person's who share the same amount of (g) may vary in the specific patterns of their abilities, as one may be strong verbally and weak in maths, while the opposite for another applies. The focus on the specific patterns of ability is valuable for occupational and educational selection. A variety of aptitude tests are available (Walsh & Betz, 1995). .
Gardner's theory of multiple intelligence, like Thurstone and Gulford, states that intelligence is more a multiple construct than a unitary construct. According to him, there are a number of relatively independent intelligences in humans. He theorised that they are independent in the sense that damage in the one, won't impair the other, or they each have different developmental processes. He proposed seven of intelligences: linguistic; logical-mathematic; spatial, musical; bodily-kinaesthetic; interpersonal and intrapersonal. This approach expanded the view of intelligence by including an assortment of different facets that are regard as part of intelligence (Van Eeden & De Beer, 2005). .
2.4 Hierarchical Theories.
Although, multiple factor theorists believed that each of the 120 factors are equally important and general, in other words none is superior to or more general than the other. In opposition, other researchers disagreed, finding that if you factor analyse these factors themselves, as opposed to factor analysing individual tests or test items, then you find higher-order factors that overlap among the factors themselves. This resulted in the postulation of the hierarchical theories of mental abilities. Factors, in these models are layered with those that are more general at the top and the more specific at the bottom (Walsh & Betz, 1995). .
According to Vernon's Hierarchical Group Factor Theory, (g) is seen as the factor at the top of the hierarchy followed by two broad "major " group factors: verbal-educational (v:ed) and spatial-mechanical (k:m).
