Intelligence

Intelligence

The study of individual differences in ability in psychology is one of the very oldest areas of psychology. Test assessing individual differences in mental ability have been of great practical value in occupational, industrial and educational psychology. The psychology of ability is one of the 4 main branches of individual differences, the others being personality, mood, and motivation. The term “mental ability” or “intelligence” is used to describe a person’s performance on some task that has a substantial information-processing component when the person is trying to perform the task as well as possible. Tests of ability involve thinking, rather than remembering and reflect how well individuals can process various types of information. Intelligence can be described as a multifaceted capacity that manifests itself in a different way across the lifespan, but in general includes the abilities and capacities to acquire and apply knowledge, to reason logically, to plan effectively, to infer perceptively, to exhibit sound judgment and problem-solving ability, to grasp and visualize concepts, to be mentally alert and intuitive, and to be able to find the right words and thoughts with facility, and to be able to cope, adjust, and make the most of new situations. You should measure well-motivated people that try to do their best at the tasks. Mental abilities reflect cognitive processes and skills which are partly developed during education or training. Therefore, it is difficult to assess without taking educational background and interests into consideration. So what is intelligence.. In our own intuitive understanding of what is intelligence, we might say that someone who is intelligent is able to make logical reasonable decisions, to size up situations quickly and well, has read extensively, and comes up with good ideas. It's not a simple thing to come up with a definition of intelligence that will satisfy everyone. For our purposes, though, we'll use very basic, simple and general definition: Intelligence is the ability to learn and understand or deal with new or trying situations. It`s the ability to apply knowledge, plan effectively, be intuitive, make sound judgments etc.
Intelligence Tests
Intelligence tests, such as “shapes” and “clues” are often used in occupational settings for various purposes, including sifting, assessment and selection of applicants, and potential diagnosis in management development programs. Other tests of intelligence often used include the Stanford-Binet test, the Wechsler Test, the WAIS, and WISC. GMA is another test that is often used. It has strong theoretical foundation, high validity and low cost. Many studies have confirmed GMA to be a good predictor of job performance and training results.
Theory and Research
In the following paragraphs, I will discuss most common approaches to studying Intelligence. These include the Psychometric Approach, Information Processing Approach, and the Neuropsychological Approach. I will then briefly discuss how intelligence varies over a lifespan and discuss recent research in genetic and biological roots of intelligence.
Psychometric Approach to Intelligence
Since it is such a vast number of mental abilities, psychometric studies try to establish the basic structure of abilities. The major aim is to understand the nature of the underlying social, biological, cognitive and other processes that cause the individual differences to emerge. Most researchers use factor analysis of the correlations between ability test items to try to reveal the underlying structure of abilities (same as they have done with personality traits – the Big Five, for example). If this is done successfully, one may be able to measure individuals` performance on a very wide range of ability tasks, correlate their scores on the items (or test) together and factor-analyze this table of correlations. The factors that emerge should represent the main dimensions of ability.
Cattell’s Ability Dimension Action Chart (ADAC)
Cattell attempted to develop a taxonomy of abilities by means of a chart showing what types of ability could logically exist, which he called Ability Dimension Action Chart (ADAC). He viewed abilities as consisting of 3 main components
Action domain: specified which aspect of the task is hard for the individual. (The demanding side of the task)
Content domain: The type of material given to the individual. (Example: verbal test, problem solving test etc.).
Process domain: Which defines mental processes the individual is supposed to perform in order to solve the problem.
However, his approach had no clear theoretical rationale and the categorization of a test according to this model is not straightforward.
Spearman and Thurstone
Spearman factored the scores between quite different scales used to measure different abilities, and found just one factor, which he called g (general ability or general intelligence). Thurstone, on the other hand, extracted 12 distinct ability factors, which he called “primary mental abilities” (PMA) [These include: spatial ability, verbal relations, perceptual speed, numerical facility, word fluency, memory, induction, restriction, and deduction]. The difference in the results could be, at least partially, explained by the fact that Thurstone analyzed correlations between subscales, whereas Spearman analyzed correlations between scales. Scales consist of several items and the way in which these items are grouped together in the first place can have important consequences for the results that are obtained. Indeed, some of the ability factors that were extracted from Thurstone’s factor analysis look remarkably similar to the scales that Spearman put into his analysis. Thurstone’s analysis was just performed on a lower, more detailed level than that of Spearman. Other limitations of Thurstone’s research include missing some areas of ability (such as social intelligence, musical skills, or judgment), as well as using only university students in his study. They have most probably been selected on the basis of high levels of general ability and it is therefore unlikely that many would have below-average ability. Most subsequent research has revealed that these factors are correlated together to varying extents. Several investigators extended the range of subscales that was entered into factor analysis and discovered more and more primary mental abilities. For example, Cattell confirmed and extended Thurstone’s results to up to 20 PMA. When these PMA were, in turn, factor-analyzed, Vernon proposed that there are 2 main second-order ability factors (or “secondaries”) – one corresponding to verbal/educational ability (“v;ed”) and the other representing practical/mechanical abilities (“k/m”). Both of these were thought to correlate together, giving general ability (Spearman’s g) at the 3rd level. However, Cattell identified 6 second-order factors, a finding that was subsequently often replicated. 2 most important factors of this model are known as fluid intelligence (Gf) and Crystallized Intelligence (Gc). Fluid intelligence is the raw reasoning ability which should develop independently of school, and which covers areas such as memory, spatial ability and inductive reasoning. Crystallized intelligence, on the other hand, consists of accumulated knowledge and knowledge that has been stored over a lifetime of experiences, and influences primaries such as verbal comprehension and mechanical knowledge.. The other four secondaries are retrieval, visualization, speed, and memory. CHC (Cattell-Horn-Carroll) Theory is derived from Cattell’s theory and identifies 10 broad abilities and 70 narrow abilities.
Other researchers have also attempted to explain the concept of intelligence. For example, Guilford’s model called “Structure of Intelligence” built up a taxonomy of abilities that should exist on theoretical grounds assuming that abilities were independent of one another. According to Guilford, any ability has 3 main quality, operations, and product, which yielded a list of 120 distinct abilities. However, this model is supported by little empirical evidence and has no obvious theoretical rationale.
In his “Theory of Multiple Intelligences”, Gardner identified 7 “intelligences” and assumed that these would be uncorrelated with each other by finding groups of behaviors that varied together regularly (tended to developed at similar age, appeared or disappeared together in geniuses and people with learning disabilities, etc.). For example, one of the intelligences identified by Gardner is “interpersonal intelligence”, which is the ability to understand other people: what motivates them, how they work, and how to work cooperatively with them. However, it is unlikely that this list is exhaustive.
IQ
In the early days of ability testing it was necessary to devise a scale of mental ability which could be easily understood by parents and teachers, and so the concept of IQ was developed by Alfred Binet. The first calculation they used was as following:
IQ = x 100
The problem with this calculation was that performance in ability test ceases to increase with age after the late teens. Ratio IQ has now been replaced with deviation IQ. Deviation IQ has a mean of 100 for any particular age group, and a standard deviation that is almost always 16. It also, by definition, follows a normal (bell-shaped) distribution. It is relatively straightforward to work out how extreme a particular IQ score is, so scores on ability tests can be converted to IQ’s for the purpose of understanding the meaning of an individual’s score on a test.
Information Processing (Cognitive) Approach
This work is characterized by carefully controlled experimental investigations of how people solve problem. This line of research has very carefully examined how people solve various types of questions.
Sternberg, in his “Triarchic Theory of Ability” suggested that any definition of intelligence should take into account the following 3 factors: Contextual subtheory, experiential/ subtheory and componential subtheory. In his eyes, there seems to be relatively little difference between being ‘intelligent” and “being successful in life in 20th century America”. Sternberg’s componential model of intelligence is one of the most influential information processing conceptualizations. This theory consists of identifying the elemental components required to perform a task and identifying the processes by which the components are combined.
Neuropsychological Approach
This approach studies the brain, functions of various parts of the brain, and interrelations of various functions to provide a deeper understanding of intelligence. One theory suggests that people whose neurons conduct information quickly along the axon and/or which transmit information efficiently and accurately across the synapses are likely to be more efficient at processing information. Experiments on this topic are important because they can show whether it is legitimate to regard abilities as the behavioral manifestations of more fundamental properties of the brain and cognitive systems. If this is so, it may be legitimate to argue that abilities can truly explain behavior. The above theory could be tested through direct measurement of Neural Conduction velocity (NCV), indirect measurement of NCV (by measuring inspection time, reaction time, or evoked potentials), or by general ability and cognitive tasks. Research has found a substantial link between inspection time and general ability, suggesting that speed and/or efficiency of neural processing is related to general intelligence. Other experiments have also suggested a similar link. However, due to difficulties in replicating some of the studies and other factors that come into play during the experiments, it is still difficult to demonstrate conclusive evidence. However, as these methods become more available to researchers, it is likely that many important studies will be conducted to deepen our understanding of intelligence.
The concept of emotional intelligence, developed by Daniel Goleman has been recently given much attention. Goleman argues that the being able to recognize one’s own and other people’s emotions, and learning how to regulate one’s own emotional state is important to understand why the most successful people are not always the most intelligent. However, Eysenck’s neuroticism factor describes, at one extreme people who are at the mercy of their negative feelings, such as those experiencing worry, guilt, anxiety and depression, and mood swings, and at the other end – people who are in touch with their inner emotional life and emotionally stable. This has raised the question of whether emotional intelligence is the same as neuroticism. There are other flaws associated wih Goleman’s research, including the fact that Goleman does not mention previous theories and does not suggest ways to measure emotional intelligence.
Geneticists have used several methods to study the genetic roots of intelligence, including twin studies, family studies, adoption studies and longitudinal studies. If we look at intelligence over the lifespan, there is substantial evidence suggesting that performance on ability tests has improved from generation to generation. This is termed the ‘Flynn Effect’. In general, scores on all ability tests improve with age up until late teens, when scores stabilize and remain fairly stable until the age of about 60. Research has shown that “Fluid ability” peaks in the early 20’s and then declines with age, whereas “Crystallized ability” is reasonably well-preserved until at least the late 50’s – what we lose in quickness of thought we may be able to make up with knowledge. General intelligence is a stable phenomenon and intelligence measured in middle childhood is a good predictor of intelligence in later life.
To summarize some of the research that has been conducted in terms of the nature vs. nurture debate regarding the origins of intelligence, Bouchard & McGue have reached a conclusion (and one that is entirely consistent with the later evidence) that approximately 50% of the variation in adult and child intelligence is attributable to our genes. People’s intellectual ability appears to be influenced in equal measure by their genetic background and their non-shared environment. The family influences (or “shared environment’) appears to have very little influence on intelligence. It appears that factors outside the family are much more potent influences on the adolescent’s IQ than any family influences. It can be concluded that even the most favorable environmental stimulation is unlikely to have the potential to change any child into a genius, as genetic factors will also influence the child’s ultimate intellectual performance, since an individual’s genetic make-up is as important as all of their environmental influences in determining his/her ultimate level of intelligence.
Recent studies have found a correlation between intelligence and leadership, but the strength of this correlation is not large. Perceptual measures of intelligence showed stronger correlation with leadership than paper-and-pencil measures, whereas stress level and directiveness moderate the relationship.
Much recent research has been devoted to the concept of Emotional Intelligence. Developed by Daniel Goleman and several other researchers, EI can be described as the ability to perceive emotion, integrate emotion to facilitate thought, understand emotions and to regulate emotions to promote personal growth. The model claims that EI includes 4 types of abilities: perceiving emotions, using emotions, understanding emotions, and managing emotions.