Intelligence

What is intelligence?

Intelligence has been defined in many different ways, including as one's capacity for logic, understanding, self-awareness, learning, emotional knowledge, planning, creativity, and problem solving. It can be more generally described as the ability to perceive information, and to retain it as knowledge to be applied towards adaptive behaviours within an environment or context.

• David Wechsler: "the aggregate or global capacity of the individual to act purposefully, to think rationally, and to deal effectively with his environment."
• Cyril Burt: "innate general cognitive ability"
• Howard Gardner: "to my mind, a human intellectual competence must entail a set of skills of problem solving, enabling the individual to resolve genuine problems or difficulties and, when appropriate, to create an effective product and must also entail the potential for finding or creating problems and thereby laying the groundwork for the acquisition of new knowledge."
• Hernstein & Murray: "cognitive ability."
• Sternberg & Salter: "goal-directed adaptive behaviour"

Galton was the first cousin of Charles Darwin, and attempted to apply Darwin's evolutionary theory to the study of human abilities. He proposed that intelligence was quantifiable and normally distributed. He wrote 'Hereditary Genius' in 1869

He believed that many aspects of human nature, including intelligence, could be measured scientifically. Galton attempted to measure intelligence through reaction time tests. For example, the faster someone could register and identify a sounds, the more intelligent that person was.

He prompted the rise of the eugenics movement; propogating the idea of improving the physical and mental makeup of the human species by selective parenthood. He contributed to our understanding of behaviour genetics and fundamental statistical knowledge.

Works on the premise of: 3 competencies and 3 cognitive processes. The triarchic theory describes 3 distinct types of intelligence that a person can possess. Sternberg calls these 3 types practical intelligence, creative intelligence, and analytical intelligence.

• Practical: relates to how you react to your environment and your ability to adapt to it or change it to suit your needs. Practical intelligence is the ability to thrive in the real world, it could be compared to common sense/"street smarts".
• Creative: relates to the way a person approaches new information or a new task. It involves a person's ability to apply their existing knowledge to new problems. There are 2 categories of creative intelligence: novelty and automatization. Novelty concerns how a person reacts the first time they encounter something new. Automatisation concerns how a person learns to perform repeated tasks automatically.
• Analytical: relates to how a person processes and analyses information, could be compared to "book smarts", since it is similar to traditional definitions of IQ and academic achievement. There are 3 components to analytical intelligence: executive components, performance components, and knowledge acquisition components.

Gardner proposed this model in his 1983 book. The theory of multiple intelligences differentiaties intelligence into specific 'modalities'.

Gardner explained that an intelligence must fulfill 8 criteria: potential for brain isolation by brain damage, place in evolutionary history, presence of core operations, susceptibility to encoding, a distinct developmental progression, the existence of savants, prodigies, and other exceptional people, and support from experimental psychology and psychometric findings. He chose 8 abilities that he held to meet these criteria: musical-rhythmic, visual-spatial, verbal-linguistic, logical-mathematical, bodily-kinesthetic, interpersonal, intrapersonal, and naturalistic.

Gardner opposes the idea of labeling learners to a specific intelligence, he maintains that his theory of multiple intelligences should "empower learners".

The g factor, which is also known as general intelligence, is a construct developed in psychometric investigations of cognitive abilities and human intelligence.

It's a variable that summarises positive correlations among different cognitive tasks, reflecting the fact that an individual's performance on one type of cognitive task tends to be comparable to that person's performance on other kinds of cognitive tasks. It predicts academic and occupational performance

Charles Spearman originally proposed the g factor. He observed that children's performance ratings, across seemingly unrelated school subjects were positively correlated, and reasoned that these correlations reflected the influence of an underlying general mental ability.

In the modern era, intelligence tests measure an array of mental abilities, broadly based on verbal and non-verbal tasks. Most tests measure a mixture of aptitude and achievement.
Intelligence tests have standardised instructions so that all administrations should be close to identical. Intelligence is scored according to standardised norms. Normative data allows comparisons to be made between individuals of different ages etc.

• Reliability - test-retest: are scores on the measure stable over time? after age 7, scores on intelligence measures show stability over time (Gregory 1998). Over a short period (between 2-12 weeks), adult IQ scores are stable at almost .96.
• Reliability - internal consistency: do all the tests in one category measure the same thing; do they show high correlations between them compared with tests in other categories? Internal consistency should be high for intelligence tests.
• Reliability - inter-rater reliability: do different scorers agree on their scores? tightly standardised tests help to avoid experimenter bias or error
• Validity - construct validity: it should be the case that only individual differences in intelligence should explain individual differences in IQ scores

• Validity - Content validity: does the test measure all of the skills and knowledge assumed to be involved in that construct? e.g, in the arithmetic subscale, does it test additions, subtraction, division etc.
• Validity - Criterion-related validity: a critical issue for intelligence measures: do they predict the kind of outcomes we expect to be related to individual differences in intelligence -
• Academic performance: better predictor of success than personality (Kaia et al, 2007)
• Job performance: intelligence positively associated with prestigous jobs and earnings (Murray, 1998)
• Mortality: Higher childhood intelligence predicts greater survival in late adulthood (Deary et al, 2004)

Binet defined intelligence as 'judgement': "a person may be a moron or an imbecile if he is lacking in judgement, but with good judgement he can never be either." He is most widely known for his contribution to intelligence - creating the first 'intelligence' scale for children.

Binet-Simon Scale: developed in 1905. Comprised a variety of tasks they thought were representative of typical children's abilities at various ages. These were thirty tasks of increasing complexity. For the practical use of determing educational placement, the score on the Binet-Simon scale would reveal the child's mental age e.g a 6-year-old who passed all the tasks usually passed by 6-year-olds, but nothing beyond, would have a mental age that exactly matched his chronological age (6.0)

Binet clearly outlined the limitations of his scale; stating that intelligence is remarkably diverse and as such, needs to be studied using qualitative rather than quanititative measures. Binet also stressed that intellectual development progressed at variable rates, and could be impacted by the environment, and wasn't solely based on genetics.

In 1916 Lewis M. Terman, a psychologist at Stanford University, revised the Binet-Simon Scale and renamed this new version the Stanford Binet scale.

It is a cognitive ability and intelligence test that's used to diagnose developmental or intellectual deficiencies in young children.

The test measures 5 weighted factors, consisting of both verbal and nonverbal subtests. The 5 factors are: knowledge, quantitative reasoning, visual-spatial processing, working memory, and fluid reasoning.

The Wechsler intelligence test was developed by psychologist David Wechsler in the 1950s. It is an IQ test designed to measure intelligence and cognitive ability in adults. The test was founded on Wechsler's definition of intelligence, which he defined as "the global capacity of a person to act purposefully, to think rationally, and to deal effectively with his environment." He believed that intelligence was made up of specific elements that could be isolated, defined and subsequently measured.This theory differed greatly from the Binet scale.

Wechsler critiqued the Binet scale; he didn't agree with the single score that the scale gave, didn't think the scale was valid for adults since it was designed for children, and also said that the Binet scale "didn't consider that intellectual performance could deteriorate as a person grew older".

The Wechsler-Bellevue tests were innovative in the 1930s because they 1. gathered tasks created for nonclinical purposes for administration as a "clinical test battery", 2. used the point scale concept instead of the age scale, and 3. included a non-verbal performance scale