Cognitive Psychology
How we think, learn, remember, and solve problems.
Thinking Systems
Dual Process Theory
Daniel Kahneman's framework for understanding thought:
| System 1 | System 2 |
|---|---|
| Fast | Slow |
| Automatic | Effortful |
| Unconscious | Conscious |
| Intuitive | Analytical |
| Parallel processing | Serial processing |
| High capacity | Limited capacity |
| Error-prone | More accurate |
| Always on | Lazy, avoids effort |
Key insight: System 1 runs the show most of the time. System 2 is expensive to engage and often just endorses System 1's suggestions.
When Each System Dominates
System 1 handles:
- Recognizing faces
- Understanding simple sentences
- Driving on empty roads
- Detecting hostility in voice
- Automatic skills
System 2 required for:
- Complex calculations
- Comparing options deliberately
- Following instructions
- Maintaining focus
- Checking validity of arguments
Memory
Types of Memory
| Type | Duration | Capacity | Example |
|---|---|---|---|
| Sensory | Milliseconds-seconds | Large | Seeing a scene briefly |
| Working (short-term) | Seconds-minutes | 4-7 items | Holding a phone number |
| Long-term | Years-lifetime | Effectively unlimited | Your childhood home |
Long-Term Memory Subtypes
| Type | Subtype | Description | Example |
|---|---|---|---|
| Explicit (declarative) | Episodic | Personal experiences | Your wedding day |
| Explicit (declarative) | Semantic | Facts and knowledge | Paris is the capital of France |
| Implicit (non-declarative) | Procedural | Skills and habits | Riding a bike |
| Implicit (non-declarative) | Priming | Unconscious activation | Faster to recognize word after seeing related word |
How Memory Works
Encoding: Getting information in
- Attention required
- Deeper processing = better encoding
- Emotional content encoded better
- Sleep consolidates memories
Storage: Keeping information
- Memories are reconstructed, not retrieved
- Memories change each time accessed
- Memories are distributed across brain
Retrieval: Getting information out
- Cue-dependent (context helps)
- Retrieval practice strengthens memory
- Interference from similar memories
Memory Failures
| Failure | Description | Example |
|---|---|---|
| Transience | Fading over time | Forgetting what you had for lunch last Tuesday |
| Absent-mindedness | Inattention at encoding | Forgetting where you put keys |
| Blocking | Temporary inability to retrieve | Tip-of-tongue phenomenon |
| Misattribution | Wrong source | Remembering where you heard news incorrectly |
| Suggestibility | Memory changed by suggestion | Leading questions alter memory |
| Bias | Current beliefs distort memory | Remembering past attitudes as consistent with current |
| Persistence | Unwanted memories | Traumatic memories that won't fade |
Improving Memory
Encoding strategies:
- Pay attention
- Elaborate (connect to existing knowledge)
- Use visual imagery
- Organize information
- Space learning out
Retrieval strategies:
- Test yourself (retrieval practice)
- Use cues and context
- Sleep after learning
- Interleave topics
Learning
Types of Learning
Classical conditioning: Associating stimuli with responses
- Pavlov's dog: bell → salivation
- Emotional associations (fear, attraction)
Operant conditioning: Learning from consequences
- Reinforcement increases behavior
- Punishment decreases behavior
Observational learning: Learning by watching others
- Modeling behavior
- Vicarious reinforcement/punishment
Reinforcement Schedules
| Schedule | Description | Effect |
|---|---|---|
| Continuous | Every response reinforced | Fast learning, fast extinction |
| Fixed ratio | After X responses | High rate, pause after reward |
| Variable ratio | After average of X responses | Highest rate, most resistant to extinction |
| Fixed interval | First response after X time | Increase toward end of interval |
| Variable interval | First response after average X time | Steady rate |
Variable ratio is most powerful. Slot machines, social media notifications use this.
Learning Principles
Spacing effect: Distributed practice beats massed practice
- Study over multiple sessions, not cramming
Testing effect: Retrieval practice beats re-reading
- Quiz yourself rather than re-read
Interleaving: Mixing topics beats blocking
- Practice different skills in same session
Desirable difficulties: Harder learning = better retention
- Challenge is good for long-term learning
Problem Solving
Problem-Solving Strategies
| Strategy | Description | When to Use |
|---|---|---|
| Algorithm | Step-by-step procedure | When accuracy essential |
| Heuristic | Rule of thumb | When speed matters |
| Working backward | Start from goal | When goal is clear |
| Analogy | Apply similar solution | When you recognize pattern |
| Decomposition | Break into subproblems | When problem is complex |
| Trial and error | Try possibilities | When solution space is small |
Obstacles to Problem Solving
| Obstacle | Description | Example |
|---|---|---|
| Functional fixedness | Only seeing typical uses | Not using coin as screwdriver |
| Mental set | Using familiar approach | Applying old solution to new problem |
| Confirmation bias | Seeking confirming evidence | Only looking for evidence you're right |
| Anchoring | Over-relying on first information | First number influences estimate |
| Availability | Judging by ease of recall | Overestimating dramatic risks |
Decision Making
Rational model: Weigh all options, calculate expected value, choose best
- Rarely how we actually decide
Heuristics we actually use:
- Availability: What comes to mind easily seems likely
- Representativeness: Match to stereotype
- Anchoring: Adjust from starting point
- Affect: Choose what feels right
Cognitive Biases
Common Biases
| Bias | Description | Mitigation |
|---|---|---|
| Confirmation | Seeking confirming evidence | Actively seek disconfirming evidence |
| Anchoring | Over-weighting first info | Consider multiple starting points |
| Availability | Overweighting memorable events | Use base rates and data |
| Hindsight | "I knew it all along" | Record predictions before outcomes |
| Overconfidence | Too certain of judgments | Calibrate with feedback |
| Sunk cost | Continuing because of past investment | Consider only future costs/benefits |
| Framing | Influenced by how options presented | Reframe from different perspectives |
| Status quo | Preference for current state | Consider default as a choice |
Why Biases Exist
Biases aren't bugs. They're features that usually work:
- Fast (no analysis required)
- Low effort (conserves cognitive resources)
- Usually accurate enough
- Adapted to ancestral environment
Problem: Modern environment differs from ancestral one. Biases misfire.
Intelligence
What Is Intelligence?
General cognitive ability: capacity to:
- Learn
- Reason abstractly
- Solve problems
- Adapt to new situations
g Factor vs. Multiple Intelligences
g (general intelligence): A statistical factor that captures shared variance across cognitive tasks
- Correlated performance across cognitive tasks
- Predicts some life outcomes (effect sizes are real but smaller than popular claims)
- Heritability estimates vary widely with age and sample, commonly reported in the 40-80% range in adulthood (remember: heritability is population-level)
Multiple intelligences (Gardner):
- Linguistic, logical-mathematical, spatial
- Musical, bodily-kinesthetic, naturalistic
- Interpersonal, intrapersonal
Reality: Both have merit. g exists, but specific abilities matter too.
Can Intelligence Change?
- Fluid intelligence: Peaks in 20s, declines with age
- Crystallized intelligence: Continues growing with experience
- Working memory: Can be trained somewhat
- Skills and knowledge: Highly malleable
Key insight: You can't dramatically change raw processing power, but you can accumulate knowledge, skills, and strategies.
Practical Applications
Improving Thinking
- Slow down - Engage System 2 for important decisions
- Consider alternatives - What else could be true?
- Seek disconfirming evidence - Actively look for what contradicts you
- Use checklists - Externalize thinking to avoid errors
- Sleep on it - Let unconscious processing work
- Get outside perspective - Others see your blind spots
Improving Learning
- Space your practice - Distribute over time
- Test yourself - Retrieval beats re-reading
- Interleave topics - Mix different subjects
- Elaborate - Connect new to known
- Teach others - Forces deep processing
- Sleep - Consolidates memory
Improving Memory
- Pay attention - Can't remember what you didn't encode
- Reduce interference - Don't learn similar things together
- Use cues - Context helps retrieval
- Review actively - Don't just re-read
- Build associations - Link to existing knowledge
- Use mnemonics - Memory techniques work