Difficulty: Introductory | Prerequisites: Development (heritability), neuroscience basics
This unit covers the major theories of intelligence, the distinction between fluid and crystallised intelligence, the Flynn effect, IQ scores and intellectual disability classifications, the nature-nurture debate around intelligence, and how genetics and environment interact to shape cognitive ability. It connects to the development material through heritability and to neuroscience through brain structure. The exam tests whether you can identify which type of intelligence a scenario describes and whether you understand how environment influences genetic potential.
Intelligence is not a single thing. Fluid intelligence (pattern recognition, novel problem-solving) declines with age, while crystallised intelligence (accumulated knowledge) tends to remain stable or increase. IQ scores are influenced by both genetics and environment, and the Flynn effect shows that population-level IQ has risen over time, likely due to environmental improvements.
Fluid intelligence
The ability to reason, solve novel problems, and recognise patterns without relying on prior knowledge. Learning new skills (rock climbing, tying knots) is an example.
In simple terms, fluid intelligence is your ability to think on your feet.
Crystallised intelligence
Accumulated knowledge and skills gained through experience and education. Gianna reciting every U.S. president in order is using crystallised intelligence. Emily knowing the rules of sudoku (but not recognising patterns) would be crystallised intelligence.
In simple terms, it is what you know from having studied, practised, and lived.
Sternberg's triarchic theory
Intelligence consists of three components: analytic (academic problem-solving), creative (novel thinking), and practical ("street smarts"). Phillip applying everyday knowledge to real-world situations is high in practical intelligence.
Gardner's multiple intelligences
Intelligence comes in distinct forms (musical, linguistic, logical-mathematical, spatial, bodily-kinesthetic, etc.). Bruce being a gifted musician but struggling with maths is best explained by Gardner's theory.
Flynn effect
The substantial, long-term increase in IQ scores across generations, roughly 3 points per decade. Environmental factors such as better nutrition are thought to contribute.
Entity theory of intelligence
The belief that intelligence is fixed and cannot change. Students who hold this view prefer low-effort, easy tasks and avoid challenges.
Incremental theory of intelligence
The belief that intelligence can grow through effort and learning. Students with this view embrace challenges.
IQ (intelligence quotient)
A standardised measure of cognitive ability with a population mean of 100 and standard deviation of 15.
Intellectual disability
Diagnosed when IQ is below 70, with onset during childhood and deficits in adaptive functioning (independent living).
Mild: IQ 50-70. Can often live independently with some support.
Moderate: IQ 35-50. Gregg (IQ 50, requires some assisted living) and Carl (IQ below 50, knows some words but limited vocabulary) fall in this range.
Severe: IQ 20-35.
Profound: IQ below 20.
Fluid = novel reasoning, pattern recognition, learning new skills (rock climbing at the ARC). Declines with age (Stephanie finding it harder to recognise visual patterns as she gets older).
Crystallised = stored knowledge, facts, vocabulary (reciting presidents, knowing WWII dates). Remains stable or increases with age.
Sternberg's triarchic theory: analytic + creative + practical. "Street smarts" = practical intelligence.
Gardner's multiple intelligences: explains how someone can excel in one domain (music) and struggle in another (maths).
Entity theory: intelligence is fixed → prefer easy tasks. Incremental theory: intelligence grows → seek challenges.
IQ scores have risen about 3 points per decade over the past century.
Likely environmental causes: better nutrition, more education, greater access to information.
"Decreases in IQ testing," "less involved parenting," and "better drug regulation" are NOT contributing factors listed on this exam.
Identical twins (even separated at birth) tend to have similar IQ scores because they share the same genes. Norman can predict his score will be similar to his identical twin's (TRUE).
However, environment determines where within the genetic range a person's IQ falls.
Gemma (high SES, tutoring, parental support) will likely have a higher IQ than Kayleigh (low SES, early work, less academic emphasis), even if their genetic ranges are the same. Environment shapes the expression of genetic potential.
Men show a high correlation between grey matter volume and IQ.
Women show a high correlation between white matter volume and IQ.
This does not mean one sex is smarter. Different neural structures can support the same level of performance.
Heritability coefficients reflect the proportion of variation attributable to genetics within populations, not within individuals.
A heritability of .4 does NOT mean 40% of one person's trait is genetic.
Students confuse fluid and crystallised intelligence. Fluid = new problems, no prior knowledge needed. Crystallised = drawing on what you already know.
Entity theory does not mean someone is unintelligent. It is a belief about whether intelligence can change.
The Flynn effect is about rising population scores, not individual improvement.
Moderate intellectual disability (IQ 35-50) involves needing assisted living but retaining some independence. Students sometimes jump to "severe" or "profound" for IQ 50.
⚠️ Crystallised intelligence = reciting presidents, WWII dates. Fluid intelligence = learning new skills, pattern recognition. Know the difference.
⚠️ Sternberg's practical intelligence = "street smarts." This appears in the Phillip question.
⚠️ Gardner's multiple intelligences = gifted musician who struggles with maths (Bruce question).
⚠️ Flynn effect environmental factor = better nutrition. Not "decreases in testing" or "better drug regulation."
⚠️ Identical twins have similar IQ scores due to shared genetics = TRUE.
⚠️ Gemma (high SES) will score higher than Kayleigh (low SES) with similar genetic potential = environment matters.
⚠️ Entity theory = comfortable with easy tasks. Incremental theory = embrace challenge.
⚠️ Intellectual disability IQ threshold = below 70.
⚠️ Fluid intelligence declines with age; crystallised remains stable or increases.
Fill in the blank: Learning to tie knots and climb rocks for the first time requires __________ intelligence. Fluid.
True or False: Crystallised intelligence declines with age. False. Fluid intelligence declines. Crystallised intelligence tends to remain stable or increase.
Fill in the blank: A student who prefers easy tasks and avoids challenges holds a(n) __________ theory of intelligence. Entity.
True or False: An intellectual disability is diagnosed when IQ falls below 90. False. The threshold is below 70.
Fill in the blank: The Flynn effect is the long-term __________ in population IQ scores. Increase.
Q: Phillip prides himself on "street smarts." According to Sternberg, what type of intelligence is he high in?
A: Practical intelligence. It involves applying knowledge to real-world, everyday situations.
Q: Stephanie finds it harder to recognise visual patterns as she ages. Which type of intelligence is declining?
A: Fluid intelligence. The ability to reason with novel information and recognise patterns tends to decline with age.
Q: Gemma and Kayleigh have similar genetic potential but very different environments. Who will likely score higher on an IQ test?
A: Gemma. Her high-SES environment, private tutoring, and parental support allow her to reach the upper end of her genetic range, while Kayleigh's less supportive environment limits her expression of the same potential.
Q: Bruce is a gifted musician but struggles in maths. Which intelligence theory best accounts for this?
A: Gardner's multiple intelligences. It proposes that different domains of ability (musical, logical-mathematical) are independent, so someone can excel in one and struggle in another.
Heritability and genetics link back to the Development unit and the nature-nurture debate.
Fluid intelligence connects to the Neuroscience unit through age-related brain changes.
Crystallised intelligence connects to the Memory unit: semantic memory is the store of accumulated knowledge that crystallised intelligence draws on.
The Flynn effect's environmental explanations tie to the Stress and Health unit: better nutrition and reduced stressors support cognitive development.
intelligence, fluid intelligence, crystallised intelligence, Sternberg, triarchic theory, analytic, creative, practical, Gardner, multiple intelligences, Flynn effect, entity theory, incremental theory, IQ, intellectual disability, mild, moderate, severe, profound, heritability, twin studies, nature nurture, environment, genetics, grey matter, white matter, PSYCH 1100, general psychology, Ohio State