Assertion (A): Thurstone held that intelligence consists of seven primary mental abilities, each relatively independent of the others. Reason (R): Thurstone's theory accepts a single general factor that dominates all the primary abilities.

Both A and R are true, and R is the correct explanation of A

Both A and R are true, but R is not the correct explanation of A

Individual Differences and Theories of Intelligence

No two people think, feel or act alike, and psychology begins its study of people by asking how those differences can be described and measured. This chapter sets out the psychological attributes the book names — intelligence, aptitude, interest, personality and values — and the methods used to assess them, and then follows the long argument about what intelligence is: one general ability, several independent ones, or a set of processes. The paper asks this ground with precision, so every theory here is tied to its theorist and to the exact parts the theorist proposed.

Individual Differences and Psychological Attributes

Individual differences are the distinctiveness and variations among people's characteristics and behaviour patterns. People differ not only in how much of an attribute they have but also in how it shows itself, and behaviour also depends on the situation: situationism is the view that the situation a person is in influences behaviour, so that a person who is usually calm may react sharply under provocation. Psychologists therefore study both the person and the situation, and describe the person through a set of psychological attributes that can be assessed.

The attributes the book names, and what each refers to
Attribute	What it refers to
Intelligence	The global capacity to understand the world, think rationally and use available resources effectively when faced with challenges
Aptitude	An individual's underlying potential for acquiring skills, given the right training
Interest	A preference for engaging in one or more specific activities relative to others
Personality	The relatively enduring characteristics that make a person distinct from others
Values	Enduring beliefs about an ideal mode of behaviour

⚠️ Aptitude is potential, not present skill

Aptitude looks forward: it is the potential to acquire a skill with training. What a person has already learned is achievement. A question that describes a student who has never played music but learns it unusually fast after lessons is describing aptitude, not interest and not achievement.

How Psychological Attributes Are Assessed

Assessment is the measurement of psychological attributes of individuals and their evaluation, often using multiple methods, in terms of certain standards of comparison. It is formal when it is objective, standardised and organised, and it is done by trained people. A good psychological test is reliable (it gives consistent scores on repeated use), valid (it measures what it claims to measure) and standardised (it has norms — the average performance of a large, representative group — against which an individual's score is interpreted).

Methods of assessment
Method	What it involves
Psychological test	A standardised and objective measure of an individual's mental and/or behavioural characteristics
Interview	Seeking information through direct conversation, as a counsellor with a client or an employer with a job applicant
Case study	An in-depth study of one person's psychological history, drawing on interviews, observation and tests
Observation	Systematic, organised and objective recording of naturally occurring behaviour
Self-report	The person gives factual information about himself or herself, or opinions and beliefs, through an interview or a questionnaire

What Intelligence Is — Two Ways of Asking

Alfred Binet was the first psychologist to work formally on intelligence; he and Theodore Simon built the first intelligence test in 1905. David Wechsler later defined intelligence as the global and aggregate capacity of an individual to think rationally, act purposefully and deal effectively with her or his environment. Gardner and Sternberg went further: an intelligent person does not only adapt to the environment but also actively modifies or shapes it. Theories of intelligence fall into two broad approaches. The psychometric approach treats intelligence as an aggregate of abilities and expresses a person's performance as a single index of cognitive ability. The information-processing approach describes the processes people use in intellectual reasoning and problem solving — how an intelligent person acts, rather than the structure of the ability.

From One Ability to Many — the Psychometric Theories

Theories of intelligence, theorist by theorist
Theorist	Theory	Core idea
Alfred Binet	Uni-factor theory	Intelligence is a single, general capacity
Charles Spearman (1927)	Two-factor theory	A general factor (g) common to all mental tasks, plus specific factors (s) for particular tasks
Louis Thurstone	Primary mental abilities	Seven relatively independent abilities: verbal comprehension, numerical ability, spatial relations, perceptual speed, word fluency, memory and inductive reasoning
Arthur Jensen	Hierarchical model	Level I, associative learning (output much like input, as in rote memory); Level II, cognitive competence (transforming input into effective output)
J.P. Guilford	Structure-of-intellect model	Intellectual traits classified on three dimensions — operations (6), contents (5) and products (6) — giving 6 × 5 × 6 = 180 cells

In Guilford's model, operations are what the respondent does — cognition, memory recording, memory retention, divergent production, convergent production and evaluation. Contents are the kind of material the operation works on — visual, auditory, symbolic (letters, numbers), semantic (words) and behavioural (information about people's behaviour, attitudes and needs). Products are the form in which the information is processed — units, classes, relations, systems, transformations and implications. The move from Binet to Guilford is the move from one ability to many: Spearman kept a general factor beneath the specific ones, Thurstone denied that any single factor dominated, and Guilford split intellect into one hundred and eighty combinations.

🧠 Numbers that pin each theory

Spearman 2 (g and s). Thurstone 7 (primary abilities). Jensen 2 levels. Guilford 6 × 5 × 6 = 180. Gardner 8. Sternberg 3. PASS 4 processes in 3 functional units of the brain. If a stem gives you the number, it has usually given you the theorist.

Gardner's Theory of Multiple Intelligences

Howard Gardner argued that intelligence is not a single entity: there are distinct types of intelligence, independent of each other, which interact and work together to find a solution to a problem. Someone very high in one may be ordinary in another. He first described eight types, and studied extremely talented people to identify them.

Gardner's eight intelligences
Intelligence	What it involves	People high in it
Linguistic	Using language fluently and flexibly to express one's thinking	Poets, writers
Logical-mathematical	Logical and abstract thinking, mathematical problem solving	Scientists
Spatial	Forming and using mental images; perceiving the spatial world	Pilots, sailors, sculptors, painters, architects
Musical	Sensitivity to musical rhythms, pitch and patterns	Musicians
Bodily-kinaesthetic	Using the whole body or parts of it flexibly and creatively	Athletes, dancers, actors, gymnasts, surgeons
Interpersonal	Understanding the motives, feelings and behaviour of other people	Counsellors, psychologists, social activists
Intrapersonal	Knowledge of one's own feelings, motives and desires	Philosophers, spiritual leaders
Naturalistic	Sensitivity to the features of the natural world; recognising plants and animals	Hunters, farmers, botanists, zoologists, bird watchers

⚠️ Interpersonal looks outward, intrapersonal looks inward

"Inter" is between people: the counsellor reading a client. "Intra" is within the self: the philosopher examining his own motives. The paper sets the two side by side as each other's distractor, and surgeons appear under both spatial and bodily-kinaesthetic, so read what the stem says the person does.

Sternberg's Triarchic Theory and the PASS Model

Robert Sternberg (1985) proposed the triarchic theory, which views intelligence as the ability to adapt to, shape and select the environment to accomplish one's goals and those of one's society and culture. It has three basic types. Componential (analytical) intelligence is the analysis of information to solve problems; it has three components — knowledge acquisition (learning how to do things), meta or higher-order components (planning what to do and how), and performance components (actually doing it). Experiential (creative) intelligence is using past experiences creatively to solve novel problems. Contextual (practical) intelligence is dealing with environmental demands encountered daily — what is popularly called "street smartness" or business sense; such people adapt to their present environment, select a more favourable one, or modify the environment to fit their needs.

The PASS model was developed by J.P. Das, Jack Naglieri and Kirby (1994). It holds that intellectual activity involves the interdependent functioning of three neurological systems, the functional units of the brain, responsible for arousal and attention, coding of information, and planning. Attention-arousal is basic: an optimal level of arousal focuses attention on the relevant aspects of a problem, while too much or too little interferes. Simultaneous processing integrates information into a meaningful whole at one time — seeing the relationships among concepts, as in solving Raven's Progressive Matrices. Successive processing handles information serially, one item after another — as in learning digits, the alphabet or multiplication tables. Planning is the essential feature of intelligence: after information is attended to and processed, it involves thinking of possible courses of action, implementing them and evaluating their effectiveness. The four processes are assessed by the Cognitive Assessment System (CAS), a battery for children aged 5 to 18.

🎯 Why PASS and Sternberg sit in a different family

Spearman, Thurstone, Jensen and Guilford describe the structure of intelligence — what abilities there are. Sternberg and PASS describe processes — what an intelligent person does with information. That is the psychometric versus information-processing split, and an item asking which theory takes the information-processing approach expects Sternberg or PASS, not Thurstone or Guilford.

Key takeaways

Individual differences are variations in people's characteristics and behaviour; situationism adds that the situation also shapes behaviour.
Aptitude is potential to acquire a skill with training; interest is a preference for activities; values are enduring beliefs about ideal behaviour.
Assessment methods: psychological test, interview, case study, observation and self-report; a good test is reliable, valid and standardised.
Spearman: g and s. Thurstone: seven primary abilities. Jensen: Level I and Level II. Guilford: operations, contents, products — 180 cells.
Gardner named eight independent intelligences, from linguistic to naturalistic; interpersonal is about others, intrapersonal about oneself.
Sternberg: componential, experiential and contextual intelligence. PASS (Das, Naglieri, Kirby): planning, attention-arousal, simultaneous and successive processing.

Practice questions (8)

Attempt each one before opening the answer. Every explanation names the tempting wrong option as well as the right one, because that is where marks are lost.

The theory that intelligence consists of a general factor common to all mental tasks together with specific factors for particular tasks was put forward by:
1. Louis Thurstone
2. Charles Spearman
3. J.P. Guilford
4. Howard Gardner
Show answer
Answer: B — Charles Spearman
Spearman's two-factor theory (1927) proposed a general factor, g, running through all mental tasks, and specific factors, s, for particular ones. Thurstone is the common slip: he rejected a dominant general factor and proposed seven relatively independent primary abilities instead.
In Gardner's theory, the intelligence that counsellors, psychologists and social activists typically show in a high degree — sensitivity to the motives, feelings and behaviour of others — is:
1. Intrapersonal
2. Naturalistic
3. Interpersonal
4. Linguistic
Show answer
Answer: C — Interpersonal
Interpersonal intelligence is understanding other people — their motives, feelings and behaviour — which is the core of counselling and social work. Intrapersonal is the near-twin trap: it is knowledge of one's own feelings and motives, typical of philosophers and spiritual leaders.
Match the theorist with the idea. A. Spearman B. Thurstone C. Guilford D. Jensen — 1. Structure-of-intellect model with 180 cells 2. Seven primary mental abilities 3. Associative learning and cognitive competence as two levels 4. A general factor and specific factors
1. A-4, B-1, C-2, D-3
2. A-2, B-4, C-1, D-3
3. A-4, B-2, C-3, D-1
4. A-4, B-2, C-1, D-3
Show answer
Answer: D — A-4, B-2, C-1, D-3
Spearman proposed g and s; Thurstone seven primary mental abilities; Guilford the structure-of-intellect model of 6 operations × 5 contents × 6 products = 180 cells; and Jensen the hierarchy of Level I (associative learning) and Level II (cognitive competence). The tempting slip swaps Guilford and Jensen, because both describe intelligence in more than one tier.
Ramesh never did well in school, but he runs a thriving shop, reads his customers well and quickly moves his business wherever demand rises. In Sternberg's triarchic theory, Ramesh is high in:
1. Contextual (practical) intelligence
2. Componential (analytical) intelligence
3. Experiential (creative) intelligence
4. Level I associative ability
Show answer
Answer: A — Contextual (practical) intelligence
Contextual intelligence is dealing with everyday environmental demands — adapting to, selecting or shaping one's surroundings — and is what is called street smartness or business sense. Componential intelligence is the analytical kind that schoolwork rewards, which Ramesh lacks; Level I ability belongs to Jensen's model, not Sternberg's.
In the PASS model, solving Raven's Progressive Matrices — where one must see how all the parts of a design relate to each other at once — chiefly calls on:
1. Simultaneous processing
2. Successive processing
3. Planning
4. Attention-arousal
Show answer
Answer: A — Simultaneous processing
Simultaneous processing integrates information into a meaningful whole at one time, perceiving relations among concepts, which is exactly what a matrix item demands. Successive processing is the trap: it handles material serially, one item after another, as in learning digits or multiplication tables.
Assertion (A): Thurstone held that intelligence consists of seven primary mental abilities, each relatively independent of the others. Reason (R): Thurstone's theory accepts a single general factor that dominates all the primary abilities.
1. Both A and R are true, and R is the correct explanation of A
2. Both A and R are true, but R is not the correct explanation of A
3. A is true, but R is false
4. A is false, but R is true
Show answer
Answer: C — A is true, but R is false
A states Thurstone's theory correctly: verbal comprehension, numerical ability, spatial relations, perceptual speed, word fluency, memory and inductive reasoning, each relatively independent. R is false because a dominant general factor is Spearman's idea, which Thurstone's theory was a reaction against — the two cannot both describe the same model.
A psychologist studies one adolescent in depth, piecing together his psychological history from interviews with him and his family, observation at school and several tests. The method being used is:
1. Self-report
2. Case study
3. Naturalistic observation
4. Standardised group testing
Show answer
Answer: B — Case study
A case study is an in-depth study of one individual's psychological history, and it draws on several methods at once — interviews, observation and tests. Observation alone or a self-report would be one strand of it, and a group test by definition is not focused on a single person.
Consider the statements. I. Aptitude is an individual's underlying potential for acquiring skills with training. II. Interest is the global capacity to think rationally and deal with the environment. III. Values are enduring beliefs about an ideal mode of behaviour. IV. Wechsler saw intelligence as the capacity to think rationally, act purposefully and deal effectively with the environment. Which are correct?
1. I and III only
2. I, III and IV only
3. II, III and IV only
4. I, II, III and IV
Show answer
Answer: B — I, III and IV only
Statements I, III and IV give the book's meanings of aptitude, values and Wechsler's intelligence. Statement II is false: it describes intelligence, not interest, which is a preference for engaging in particular activities over others. Dropping IV as well leaves out Wechsler's definition, which is correctly stated.