LECTURE NOTES ON INTELLLIGENCE
Prepared for PSY205 by GORDON VESSELS with the support of James Neill
The following is a combination of my thoughts and expressed knowledge about intelligence, and those of James Neill who has an excellent website with good material, and who teaches an introductory psychology course in Australia. His material is used here with his permission. To get more information from Dr. Neill, visit the following websites.
http://www.wilderdom.com/JamesNeill/Jamesbio.html http://www.wilderdom.com/index.html http://www.wilderdom.com/personality/intelligence.html#Why
Introduction by Gordon Vessels
As a psychologist who has tested thousands of children, I define intelligence as the full array of mental abilities (including memory and reasoning skills) that together synergistically reflect how “smart” people are, and how capable they are in terms of specific mental abilities or mental processing skills and challenging real-world situations. By defining intelligence this way, I have (1) endorsed the concept of general intelligence proposed by Charles Spearman many years ago, (2) accepted that there is some truth reflected by the results of factor analysis, a statistical method he used to arrive at the notion of “g,” and (3) acknowledged that people can be brilliant and far stronger in one form of intelligence than others. They may have mental strengths that allow for excellence in an art form, a type creative problem solving, or the ability to adapt and prosper when faced with challenges in the real world while lacking abilities that constitute another form of intelligence. Am I suggesting that theorists who believe in “g” and those who do not and believe in multiple intelligences are both right? Yes I am. But to understand to what extent and in what specific ways they are right, we must look at each more closely and critique them in terms of the detail of their propositions.
Before looking at these theorists and test makers more closely, it may be useful to place the study of intelligence and memory into an historical context. Most importantly, this history parallels the origins and growth of the field of psychology as a whole, meaning that it emerged with psychology, which had its origins in physiology and philosophy and their intersection in the 19th century. Intelligence has been investigated by (a) those relying on psychometrics and statistics and (b) cognitive psychologists who have relied more on their understanding of how we think and recall without relying on statistical tricks to uncover related components of intelligence.
Early on, the emphasis was more on nature as the main cause of how smart people are rather than nurture, which implies that environment plays an important role in shaping our intelligence. Twin studies have pretty much demonstrated that the proportional contribution of each is about 50%, but the interaction of (a) genetics and physiology on the one hand, and (b) learning opportunity and environmental stimulation on the other unfolds uniquely for each individual. This makes it difficult to predict the ultimate intelligence of each person.
One unfortunate outcome of the emphasis on nature was a movement to improve the human species by allowing only those with the right test scores and/or pedigree to reproduce, vote, be free, etc. This was one of the main reasons why many concluded that slavery in the United States and elsewhere was acceptable. People actually had themselves convinced, thanks the Eugenicists, that some races (the concept itself is suspect on scientific grounds) were more evolved than others and thus smarter on the average. For those interested, the documentary PBS program Journey of Man largely demonstrates that the concept of race is unfounded as a physical as apposed to cultural concept, and it does so by connecting us all genetically. In spite of such evidence and the known accomplishments of people from all “races,” people like Arthur Jensen continue to believe in racial differences and continue to make the “nature over nurture” argument.
Let me move now to a few other definitions offered by so-called experts, and some by college students. You may share my conclusion that those offered by students sound better. These definitions were extracted from James Neill’s Wilderdom website (2005).
Definitions of Intelligence Offered by Social Scientists
"The ability to carry out abstract thinking" (Terman, 1921).
"The capacity to learn or to profit from experience" (Dearborn, 1921).
"A global concept that involves an individual's ability to act purposefully, think rationally, and deal effectively with the environment" (Wechsler, 1958).
"Intelligence is a general factor that runs through all types of performance" (Jensen).
"A person possesses intelligence insofar as he has learned, or can learn, to adjust himself to his environment" (Colvin, cited in Sternberg, 1982, p.30).
"Intelligence is the ability to use optimally limited resources - including time - to achieve goals" (Kurzweil, 1999).
Definitions Offered by University Students
"Intelligence is the ability of an organism to learn, grow and adapt efficiently and effectively to a changing environment" (Bart Taylor, n.d.).
"Intelligence is the ability to predict, interpret, and overcome random situations that occur in life" (Andrew Olson, n.d.).
"Intelligence is the capacity of an organism to make free-will choices that make possible further opportunities and potentialities for the advancement and continuity of life" (Terese Hutchison, n.d.).
"Intelligence is the capacity for abstract rational thought that enables creativity and decision making" (Annemarie Nicol, n.d.).
"Intelligence is the ability to learn from your mistakes and not repeat them (when possible) and to apply what you have learnt to your life and make it better" (Michelle Deponte, n.d.).
"Intelligence is a person's ability to learn and apply what he/she has learned to new and existing situations and circumstances" (anonymous, n.d.).
The History of Intelligence Testing
Theories of intelligence and the construction of intelligence tests were dominated for more than one hundred years by psychometric theorists like Charles Spearman, Alfred Binet, David Wechsler, and Alan Kaufman (who is still living). But the tide seems to be turning more in the direction of cognitive psychologists who are more theory-driven and conceptually clear about the various types of thinking and memory we exhibit. Two leaders of this new trend are Howard Gardner and Robert Sternberg, but there are others who have been at it longer including Feurerstein. They have come at the subject of intelligence from a whole different perspective, and one that those who do testing (school psychologists and clinical psychologists) have resisted. It will be interesting to see how it plays out and if testing will be replaced by less quantitative methods of assessing mental potential. If you follow the cognitive psychologists shown in lavender rectangles on my PPT slide (the one that has numerous psychologists listed), you will get a feel for what these individual have contributed and how different their methods truly are. Just click on the names which are linked to websites.
The following is a brief description of some of the important figures included in this chart. Much of this information comes from James Neill (2005) with his written permission. His work was not used to construct the chart with links that I described above, but it was drawn from heavily in the paragraphs that follow. Many of the paragraphs in the remainder of this lecture are quotations extracted from Neill’s website.
1. Francis Galton: The 1st Modern Attempt (late 1800s)
“Intelligence tests are grounded in the work of Francis Galton in the late 19th century. Galton wanted to measure intelligence as directly as possible. He explored reaction time and sensorimotor measurements, which went along with the . . . emphasis on perception . . .”
(Neill, 2005: http://wasp.canberra.edu.au/uc/lectures/scides/sem992/unit4311/Lecture2.html).
2. Alfred Binet: The origins of IQ Testing (early 1900’s)
“Alfred Binet created the first intelligence test as we know them today. He is commonly known as the ‘father’ of IQ testing. In 1904, he was commissioned by the French Ministry of Public Instruction to develop techniques for identifying primary grade children whose lack of success in regular classrooms suggested the need for special education (Gould, 1981). In 1905 he produced the Binet-Simon scale [with Theodore Simon] - the first intelligence test. He used a series of 30 short tasks related to everyday problems” (Neill, 2005: www.wilderdom.com/personality/L1-5KeyPlayers.html).
- attending to simple instructions
- naming parts of the body
- comparing lengths and weights
- counting coins,
- assessing which of several faces is 'prettier'
- naming objects in a picture
- recalling the number of digits a person can recall after being shown a long list
- defining words
- filling in the missing words in sentences
“This was a turning point in psychology: a new type of test had been produced in which the average level of performance was the criterion. In 1908 and again in 1911, the test was revised. The current revision in use today is the fifth” (Neill, 2005: http://www.wilderdom.com/personality/L1-5KeyPlayers.html ).
3 & 4. Terman (1916) and Stern (1912)
“Lewis Terman in the US decided to use Binet's test but found that the French norms didn't work for Californian children. He revised the test by . . . gathering new age norms, and extended the upper age limit. This became the Stanford-Binet revision of 1916. This is where the Intelligence quotient was first used. The Intelligence Quotient or IQ quantified intelligence and allowed for comparing individuals to others. The IQ was a ratio IQ which means it expressed the relationship between an individual’s mental age and chronological age. In 1912 Wilhelm Stern proposed the following: IQ = mental age x 100 divided by chronological age. This formula works fairly well for children but not for adults (Thomson, 1968; Weinberg, 1989)” (Neill, 2005: http://www.wilderdom.com/personality/L1-5KeyPlayers.html).
5. Yerkes: Army Tests (WWI)
“Robert Yerkes, a psychologist and army major, assembled a staff of 40 psychologists [including Terman] to develop a group intelligence test. This resulted in the Army Alpha and Army Beta tests. Over a million people were tested, but not until late in the war” (Neill, 2005: http://www.wilderdom.com/personality/L1-5KeyPlayers.html).
6. Charles Spearman: “g” (1920’s)
“Until the 1920s, approaches to intelligence testing had been very practical . . . Another approach to understanding intelligence involved analyzing data that were already collected.
Charles Spearman (1927) analyzed the relations among experimental intelligence tests using a statistical method called factor analysis. He contended that people who do well on some intelligence tests also do well on a variety of intellectual tasks. He also observed that if people did poorly on an intelligence test, then they also tended to do poorly on others. He observed correlations among performance on a variety of intellectual tasks. He proposed a 'two-factor' theory of intelligence” (Neill, 2005: http://www.wilderdom.com/personality/L1-5KeyPlayers.html).
- General Intelligence (g): which was required for performance of mental tests of all
kinds; he called this a kind of 'mental energy' that underlies the specific factors
- Special Abilities: which were required for performance on just one kind of mental test.
Scores on a verbal comprehension test are largely determined by one’s level of general
intelligence but they are also affected by one’s specific ability to perform verbal comprehension
tasks (Neill, 2005).
“But the main thrust of Spearman's analysis was general intellectual capacity. This formed a major theoretical platform for many subsequent approaches to intelligence. Spearman was excessively enthusiastic about g. He advocated restricting voting rights to people whose g exceeded a certain level, and he was a Eugenicist (the term “eugenics” comes from the Greek word ‘Eugenes,’ meaning well-born) who argued that only people with a certain level of g or higher should be allowed to have offspring” (Neill, 2005: http://www.wilderdom.com/personality/L1-5KeyPlayers.html).
7. Weschler: Intelligence Scales for Adults and Children (1939 - present)
“Wechsler felt that the Binet scales were too verbal for use with adults, so he designed an instrument with subtests to measure both verbal and nonverbal abilities. The original Weschsler-Bellevue test in 1939 was widely used . . . In 1949, he produced the Wechsler Intelligence Scale for Children (WISC). In 1955, he produced a revision of the adult scales named the Wechsler Adult Intelligence Scale (WAIS). Later he produced a scale which could be used with pre-school and primary children called the WPPSI. These scales have all been revised, but still show a distinct resemblance to the original 1939 scale” (Neill, 2005: http://www.wilderdom.com/personality/L1-5KeyPlayers.html). The most recent revision, the WISC-IV, is greatly improved over the WISC-III and more in line with intelligence theories.
8. Thurstone: Primary Mental Abilities (1930’s)
“Another factor analyst, Thurstone (1938), accepted Spearman's g factor. But he disputed its importance. He said that g is in fact a second order factor or phenomenon - one which arises only because the primary or first-order factors are related. Thurstone identified 7 primary mental abilities which he judged to be more important (Neill, 2005).
1. Verbal Comprehension: vocabulary, reading, comprehension, verbal analogies, etc.
2. Word fluency: the ability to quickly generate and manipulate a large number of words with specific characteristics, as in anagrams or rhyming tests
3. Number: the ability to quickly and accurately carry out mathematical operations
4. Space: spatial visualizations as well as ability to mentally transform spatial figures
5. Associative Memory: rote memory
6. Perceptual Speed: quickness in perceiving visual details, anomalies, similarities, etc.
7. Reasoning: skill in a variety of inductive, deductive, and arithmetic reasoning tasks. (Thurstone, 1938)
“Thurstone's proposed the first multi-factor approach to intelligence. His position that intelligence is better described and measured by assessing distinct primary mental abilities, rather than a single factor g, has growing support today (see Flanagan, Genshaft & Harrison, 1997; Murphy & Davidshofer, 1998)” (Neill, 2005).
9. Raymond Cattell: Fluid & Crystallised Intelligence (1960’s)
Raymond Cattell (1963) proposed that there are two related but distinct components of g: fluid and crystallized intelligence.
Fluid is the ability to see relationships, as in analogies, and it is essentially reasoning ability
Crystallized is acquired knowledge and skills.
Fluid intelligence begins decreasing in middle age; crystallized intelligence increases throughout life. Mathematicians and scientists whose work requires extensive fluid intelligence typically do their best work in their 30s while those in fields like history and philosophy do their best work in their 40s and beyond.