Cognition, Language, and Intelligence

Problem Solving and Decision Making

Problem solving uses trial and error, algorithms (step-by-step, guaranteed), and heuristics (fast shortcuts, error-prone). Barriers: functional fixedness (cannot see novel uses — Duncker's candle problem), mental set (persisting with failing strategies), and confirmation bias (seeking confirming evidence). Dual-process theory: System 1 (fast, automatic, intuitive) and System 2 (slow, deliberate, analytical).

Heuristics, Biases, and Cognitive Errors

Heuristics are efficient shortcuts producing predictable errors. The availability heuristic judges probability by how easily examples come to mind (overestimating plane crash risk after news coverage). The representativeness heuristic judges by prototype matching, causing base-rate neglect (assuming a quiet person is a librarian, ignoring that farmers vastly outnumber librarians). Anchoring bias is over-reliance on an initial value. Belief perseverance maintains beliefs despite contrary evidence. Framing effects (Tversky and Kahneman) show that presenting identical options as gains vs. losses changes decisions: losses loom larger than equivalent gains (loss aversion, central to prospect theory).

Language Structure and Development

Language operates at multiple structural levels: phonemes (smallest sound units), morphemes (smallest meaning units — "un-break-able" has three), syntax (grammatical rules for combining words), semantics (meaning), and pragmatics (social conventions of use). Development follows a universal sequence: cooing (~2 months) → babbling (~6 months) → one-word stage (~12 months) → two-word/telegraphic speech (~18-24 months) → complex sentences. Chomsky's nativist theory proposes an innate language acquisition device (LAD) and universal grammar, arguing syntax acquisition outpaces what imitation alone can explain. Skinner's behaviorist account emphasizes reinforcement. The critical period hypothesis (Lenneberg) holds that language acquisition is optimal before puberty.

Theories of Intelligence

Intelligence is the capacity to learn, solve problems, and adapt. Spearman's g factor posits a single general ability underlying all cognitive tasks. Thurstone identified seven primary mental abilities. Gardner's theory of multiple intelligences proposes eight types: linguistic, logical-mathematical, spatial, musical, bodily-kinesthetic, interpersonal, intrapersonal, and naturalist. Sternberg's triarchic theory distinguishes analytical (academic), creative (novel generation), and practical (everyday adaptation) intelligence. Emotional intelligence (Salovey and Mayer) involves perceiving, understanding, managing, and using emotions. The Cattell-Horn model differentiates fluid intelligence (Gf: novel reasoning, declines with age) from crystallized intelligence (Gc: accumulated knowledge, stable or increases). The Flynn effect — rising IQ scores across generations — reflects improved nutrition, education, and environmental complexity.

Creativity and Insight

Creativity produces ideas that are both novel and useful. Divergent thinking — generating multiple solutions to open-ended problems (e.g., "list all uses for a brick") — is its cognitive hallmark, contrasted with convergent thinking that finds a single correct answer. Insight is the sudden "aha" realization without step-by-step reasoning, associated with right anterior temporal lobe activation. Incubation — setting a problem aside and returning later — allows unconscious processing to yield breakthroughs. Barriers include functional fixedness and mental set.

Cognitive Development Theories

Piaget's stage theory proposes four qualitatively distinct stages. Sensorimotor (0-2 years): learning through senses and motor actions; object permanence develops. Preoperational (2-7 years): symbolic thought with egocentrism (three mountains task), animism, and lack of conservation (understanding quantity stays constant despite appearance changes). Concrete operational (7-11 years): logical reasoning about concrete objects; conservation, reversibility, and classification are mastered. Formal operational (11+ years): abstract, hypothetical, and systematic reasoning emerges. Vygotsky's sociocultural theory holds that cognitive development is driven by social interaction and cultural tools, especially language. The zone of proximal development (ZPD) is the range of tasks a child can accomplish with guidance but not independently. Scaffolding is temporary support within the ZPD, gradually withdrawn as competence grows. Private speech guides problem solving, then internalizes into inner speech.

How it works

Cognition arises from distributed networks. The dorsolateral prefrontal cortex supports working memory, planning, and cognitive flexibility; the anterior cingulate monitors conflict. System 1 relies on amygdala and basal ganglia for rapid pattern matching; System 2 recruits dorsolateral PFC. Language localizes to the left hemisphere: Broca's area (production), Wernicke's area (comprehension), connected by the arcuate fasciculus. Piagetian transitions correlate with frontal lobe maturation; Vygotsky's ZPD maps onto social scaffolding shaping prefrontal circuits. Insight involves gamma-band bursts in the right anterior temporal lobe.

How it works

Cognition arises from distributed networks. The dorsolateral prefrontal cortex supports working memory, planning, and cognitive flexibility; the anterior cingulate monitors conflict. System 1 relies on amygdala and basal ganglia for rapid pattern matching; System 2 recruits dorsolateral PFC. Language localizes to the left hemisphere: Broca's area (production), Wernicke's area (comprehension), connected by the arcuate fasciculus. Piagetian transitions correlate with frontal lobe maturation; Vygotsky's ZPD maps onto social scaffolding shaping prefrontal circuits. Insight involves gamma-band bursts in the right anterior temporal lobe.

Comparisons

• Biology: Broca's aphasia (nonfluent, intact comprehension) vs. Wernicke's aphasia (fluent, impaired comprehension). Arcuate fasciculus damage causes conduction aphasia (impaired repetition).
• Sociology: Vygotsky links cognition to socialization and culture. Cross-cultural IQ testing raises validity concerns.
• Research methods: IQ tests require standardization, reliability, and validity. The Flynn effect shows cohort effects in IQ scores.
• C/P: Prospect theory: risk-averse for gains, risk-seeking for losses.

Common confusions

• "Availability = representativeness." Availability = ease of recall; representativeness = prototype matching. Plane crash fear after news = availability. Assuming tall = basketball = representativeness.
• "Piaget's stages have fluid age ranges." The MCAT expects: sensorimotor 0-2, preoperational 2-7, concrete operational 7-11, formal operational 11+. Object permanence = end of sensorimotor; conservation = concrete operational.
• "Broca's aphasia = comprehension deficit." Broca's is nonfluent (production impaired, comprehension preserved). Wernicke's is fluent but meaningless (comprehension impaired). Do not reverse them.
• "Fluid intelligence = creativity." Fluid intelligence (Gf) is novel reasoning; creativity is divergent thinking and idea generation. Related but distinct.
• "Scaffolding = ZPD." ZPD defines the gap between independent and guided performance. Scaffolding is the support process within that gap. Related but distinct.
• "Framing effect = anchoring." Framing alters choice by presenting options as gains vs. losses; anchoring is over-reliance on an initial number. Preferring "90% survival" over "10% mortality" = framing.

Quick review

• Problem solving: algorithms (guaranteed) vs. heuristics (fast, error-prone). Barriers: functional fixedness, mental set, confirmation bias. System 1 (fast) vs. System 2 (slow).
• Heuristics: availability (ease of recall), representativeness (prototype matching, ignores base rates), anchoring (initial value). Framing: gain vs. loss presentation changes choice — loss aversion (prospect theory).
• Language: phonemes → morphemes → syntax → semantics → pragmatics. Cooing → babbling → one-word → two-word → complex. Broca's (production) vs. Wernicke's (comprehension). Chomsky's LAD vs. Skinner. Critical period.
• Intelligence: Spearman's g, Thurstone's 7 abilities, Gardner's 8 types, Sternberg's triarchic (analytical/creative/practical). Fluid (Gf: declines with age) vs. crystallized (Gc: stable). Flynn effect.
• Piaget: sensorimotor (0-2, object permanence), preoperational (2-7, egocentrism, no conservation), concrete operational (7-11, conservation), formal operational (11+, abstract/hypothetical).
• Vygotsky: ZPD (can do with help), scaffolding (support within ZPD). Private speech internalizes into inner speech.
• Creativity: divergent (multiple solutions) vs. convergent (best answer) thinking. Insight: sudden "aha" solution. Incubation: unconscious processing during breaks.