crystallized intelligence
the ability to solve problems using already acquired knowledge
Example: Using math formulas you learned in school to solve a real-world problem.
fluid intelligence
Your ability to think logically and solve new problems without relying on prior knowledge.
Abilities that rely on information-processing skills such as reaction time, attention, and working memory
Example: Figuring out a new type of puzzle you’ve never seen before.
general intelligence (g)
measure of an individual’s overall intelligence as opposed to specific abilities
functional fixedness
the tendency to perceive an item only in terms of its most common use
When you can’t see a new use for something because you’re stuck on how it’s usually used.
heuristic
Heuristics are mental shortcuts our brain uses to make decisions quickly and with little effort.
shortcut or rule of thumb for finding a solution to a problem
intelligence quotient (IQ)
mental age divided by chronological age times 100
morphemes
smallest meaningful units in a language, such as syllables or words
phoneme
The smallest unit of sound in a language that can change meaning
Example
Same spelling, different phonemes
- c in cat → /k/
- c in city → /s/
- Same letter ❌
- Different sounds ✅ → different phonemes
Different spelling, same phoneme
phone → ph
fun → f
Different letters ❌
Same sound /f/ ✅ → same phoneme
Availability Heuristic
Easy to recall = common
We judge how likely something is based on how easily we can think of examples.
👉 If it comes to mind quickly, we think it happens more often.
The availability heuristic occurs when people judge frequency or likelihood based on how easily examples come to mind, whether from personal experience or repeated exposure in the media.
Example:
You see multiple TikToks about people failing their driving test.
You start to think most people fail, even though the majority actually pass.
👉 Those videos stick in your mind, so the event feels common.
Representativeness Heuristic
Matches a stereotype
We judge something based on how similar it is to a typical example - prototype/stereotype
A student wears a hoodie, skips class, and talks back to teachers.
You assume they are bad at school.
But:
Appearance ≠ actual academic ability
You’re matching them to a stereotype, not evidence
Example:
Someone is quiet, loves books, and studies a lot.
You assume they are a librarian, not a salesperson
Recognition Heuristic
Familiar = better
When choosing between options, we assume the one we recognize is better, more common, or more important.
👉 “If I’ve heard of it, it must be better.”
Example:
You choose a university you’ve heard of over one you haven’t—even if you don’t know much about either.
Affect Heuristic
Feelings guide decisions
We make decisions based on our emotions rather than logic.
👉 “How do I feel about this?”
If it feels good → I think it’s good.”
“If it feels bad → I think it’s bad.”
Example:
You meet a teacher on the first day who is smiling, kind, and warm.
You immediately think:
- “They’re a good teacher.”
Even though:
- you haven’t had any tests yet
- you don’t know their grading style
Framing Effects
Our decisions change depending on how information is presented, even if the facts are the same.
👉 The “frame” influences your choice.
Example:
“This surgery has a 90% survival rate” → sounds good
“This surgery has a 10% death rate” → sounds scary
Same statistics, different decisions.
Maximizers vs. Satisficers
Maximizer = tries to pick the best option (more stressed).
Satisficer = chooses “good enough” (happier, less stress).
Categorization
Grouping things based on shared features or commonalities.
Eg: grouping chairs, stools, and a sofa together because they all share the characteristic of having 4 legs
Concept
A mental representation that groups objects, events, or ideas around a common theme (broader).
Example: grouping chairs, stools, and sofa together because they are all seating objects (much broader)
Classical Categorization (Defining Attribute Model)
Objects are categorized by a specific set of rules or features.
Membership is all-or-none.
Classical Categorization (Defining Attribute Model) says that an object belongs to a category only if it has all the required defining features.
👉 It’s very strict: yes or no, no “kind of.”
Examples:
Triangle = 3 sides, 3 angles
Bird = lays eggs, has wings, can fly
Prototype Model
You compare everything to your ONE “average dog” (golden retriver).
Objects are categorized by how closely they match the “best example” of a category.
Example: “Average bird” → robin, sparrow (prototypes) vs. penguin (less typical)
Exemplar model:
Uses all examples we’ve encountered to form a category.
Uses all examples we’ve encountered to form a category.
We compare new objects to these specific examples, not just a single prototype.
You compare it to MANY dogs you’ve seen before: husky, poodle, etc.
So when you see a new kinda dog, you don’t check if it fits your “average dog.” You think “does it fit in with the rest of the dogs I know about?
Taxonomic Categorization
Taxonomic categorization groups objects according to shared properties and class membership..
👉 It’s about “what kind of thing is this?”
Example:
→ Group “dog” with “cat” because they’re both animals.
Apple, banana, orange → fruit
(not because you eat them together, but because they belong to the same category)
Chair, table, couch → furniture
Thematic Categorization
Group things based on relationships or context, association
Example:
→ Group “dog” with “bone” because dogs eat bones.
Validity (construct)
Does the test measure what it’s supposed to?
Reliability
Are the test results consistent?
The Weschler Adult Intelligence Scale (WAIS)
The WAIS-IV indices are basically the four main scores that make up the Wechsler Adult Intelligence Scale (WAIS-IV). Each one measures a different type of cognitive ability in adults.
It tests how well adults think, reason, and solve problems in different areas, not just one overall skill.
Verbal Comprehension Index (VCI): How well you understand and use language.
Working Memory Index (WMI): How well you hold and manipulate information in your mind.
Perceptual Reasoning Index (PRI): How well you solve non-verbal, visual, or spatial problems.
Processing Speed Index (PSI): How quickly you can process simple information.
