In psychology, there are many theories, among which Intelligence is one of them. Theories of Intelligence have been developed by various factors which analyse the structure of Intelligence. Among different intelligence theories, we will be discussing two notable theories developed by J.P. Guilford and Philip E. Vernon. Both of them have evolved their theories about the structure of Intelligence. In this article, we shall look into the Guilford Vernon theory.

The Guilford Vernon Theory

Referring to the g factor theory, Philip E. Vernon proposed this theory of Intelligence. He extracted the g factor from another ability test and thereby found that the content can be divided into two distinct parts, namely:

• verbal-educational factor or v: ed that refers to the verbal and educational abilities
• perceptual-mechanical skill factor or k:m that refers to the spatial, practical, and mechanical abilities

J.P. Guilford developed the structure of Intellect Theory, better known as the SI model. According to Guilford, Intelligence is a combination of numerous abilities independent in nature. To learn about these mental abilities, he applied the factor analytical method.

Philip E. Vernon’s theory of the verbal-perceptual model was influenced by the theory of g factor proposed by Spearman. So, here he emphasised the g factor.

Guilford: Structure Of Intellect Theory (SI) Model:

According to the model Guilford presented, he identified a few significant operations of Intelligence: 

• Cognition: Refers to the capability to comprehend, understand, discover, and become more aware 
• Memory: An ability to memorise more information and data
• Convergent Thinking: Organising with the help of reasoning or any other process which can help in finding valuable solutions to a problem
• Divergent Thinking:  It leads to various possible answers or solutions to a problem
• Evaluation: To conclude the process by determining if the answer is accurate or valid

Concept – Guilford’s The Structure Of The Intellect:

Content Dimension

The content dimension includes the areas of information where the operations can be applied. Primarily, it is divided into the following categories:

• Semantic- Topics or information that is perceived in the form of sentences, words, or even silently by one’s mind
• Symbolic- Topic or information that is perceived in the form of signs and symbols that might have no meaning by themselves
• Auditory- Information that arises from the cochlea stimulation of one’s ears
• Behavioural- Information that is perceived as the individual acts of a person or animal

Product Dimension

The product dimension consists of particular operations to each of the specific content. Total six products are found, which are:

• Elements /Units- Represent fragments of information
• Classes- Grouping the elements
• Relation- Difference, similarities, and contingencies amongst the classes
• System Theories – Relationships among the interaction parts
• Transformations- How things change (concepts)
• Implications- Projection from theories to events that have never been observed or given a thought

Classification of Intelligence 

Taking a look at the abilities, which Guilford classifies as four kinds of Intelligence:

• Figural Intelligence can be considered as concrete Intelligence
• Symbolic Intelligence mixes up the usage of numbers and words. It may be regarded as abstract Intelligence.
• Semantic Intelligence improves our ideas and facts
• Social Intelligence is the nonverbal one that helps in shaping the behaviour

Despite various criticisms, his theory has left a significant mark in the field of research of Intelligence. Different tests are being used in modern intelligence testing, developed and modified under Guilford’s guidance.

Vernon: The Hierarchical Group Factor Theory

Vernon presented the hierarchical group factor theory, which deals with the structure of human intellectual abilities. The top of this hierarchy was the general factor or “g factor” of Spearman. It was accounted as the largest source of variance in Intelligence.

Vernon’s theory has two factors which include group factor and common factor. According to him, the hierarchy of mental organisation consists of various levels. Intelligence is the combination of capacities of the mind. It differs in a different level as per quantity and quality. It works from lower level to higher level. This consists of:

• Sensation
• Movements 
• Perception
• Coordination of movement
• Memory
• Habit formation
• Apprehension of relation

Stages in the Hierarchical Group Factor

The hierarchical stage includes factors like:

• Generalisation
• Logic
• Thought process
• Abstraction etc.

Apprehension of relation includes creative activity and aesthetics.

After going through eight analyses, Vernon found the “g” factor to cover up more than twice as much variance as all the group factors combined. 

After the removal of the g test, the factors can is divided into two main groups:

• Verbal-Numerical Education (v: ed) factors
• Practical-Mechanical-Spatial-Physical (k: m) factors

Advantages Of Hierarchical Group Factor Theory

• Identifying the specific aptitude test helps make the counselling and guidance program economical and helpful by specifying an individual’s aptitude. In addition, it makes the guidance service a scientific one.
• Inter-relationship of psychological behaviour is best appreciated when scientific analysis of the underlying structure of abilities is available. 
• This test is more valid in structure and reliable for the purpose of guidance since it is constructed by the knowledge of the structure of human abilities.
• This test is a scientific and objective-oriented one, which can be provided with the help of structure of abilities.
• It helps in developing a theory of test which is based on the structure of abilities for educational purposes and vocational guidance.

Conclusion

Numerous tests are designed and constructed to measure Intelligence. No attempts have been made to review the theories of Intelligence formulated so far. This measurement helps understand the nature of intelligence and individual differences among students.