a category
a group of objects that have the same properties
natural category
artefact category
nominal category
1) category that occurs in the natural world
2) a group of man made objects- designed with a specific function
3) objects or ideas that are put together due to arbitrary characteristics.
Arbitrary: based on preference instead of natural occurrence
classical theory of concepts ,
individually necessary, jointly sufficient
category membership
hierarchical order of concepts
concepts contain a rule as well as individual properties that are necessary and features that when together present are
jointly sufficient,
individually necessary
The mind will represent a list of items that are necessarily part of the category
category membership: binary
–> no intermediate solution
–> classification is not affected by context
Empirical data that supports the classical theory
Task :
people had to perform categorization on different forms of concepts.
- simple concepts: the object has to be a triangle
- conjunctive concepts: the object has to be a green triangle
- disjunctive concepts : The object has to be either green or a triangle.
–> pp had the hardest time to filter out disjunctive concepts because they had to keep the information in mind.
–> further pp had difficulties to categorize if they had to keep things from previous trials in mind.
–> attention and short term memory are limited–> the binary categories are the fastest and easyest to process
whats successive scanning, cervative focusing and focus gambling ?
…
What are the counterarguments to this theory ?
theoretical objection:
It is not logical that the information that is often vague can lead to clearcut binary categorisation.
family resemblance:
Members of a family for instance birds can look very different to one another and are still part of one group.
Prototype thoerie
the theory states, that humans categorise based on the degree of typicality an item has compared to the prototype.
Typicality gradient:
The prototype has the highest typicality gradient.
the more features fit the higher the typicality gradient is.
Features:
There is not binary system, features are not necessary.
An average of the description of an object/ group member is compared to the prototypes characteristics.
Disadvantages of the prototype theory.
this theory assumes that people use superficial features in order to categorise. Typicality is no core concept of a group.
( what about more central attributes, mushrooms l-ook like plants but they are centrally something different)
- does not say anything about the causal mechanisms ( what is meant ? )
Fails to account for the people’s knowledge outside the prototypes boundaries.
- people can judge items on their typicality does not mean that they are represented like this in their head.
- it can not deal with untypicality
Exemplar based theory
- exemplars of every category are kept in memory.
- in order to categorise the object is compared to the exemplars .
- every time we see a member of a category we store it with the the other exemplars in memory.
Advantages exemplar based theory
- exemplars of every category are kept in memory.
- in order to categorise the object is compared to the exemplars .
- every time we see a member of a category we store it with the the other exemplars in memory.
Disadvantage exemplar based theory
- memory storage is limited, with this theory the memory is overloaded.
- dissociation between category and typicality have been demonstrated.
- it does just relate to the way things look. Arbitrary categorization are not taken into account.
Explanation based theory
- usage of common sense explanations to categorize things
- the explanations contain superficial and central attributes
- this theory was invented in order to fill the gaps that were created by the other theories.
–> could be seen as a complementary seen, allows to explain how we categorize concepts that are not based on visual objects.
Disadvantages explanation based theory
- lack of specificity
- the explanation is based on a concept which is base on the specificity
- the explanations rely on common knowledge which is not guaranteed.
Prototype categorization in action
super ordinate: furniture
basic level: chair
subordinate: desk chair
Racial essentialism, Essentialism and creativity experiment
Essentialists belief, that racial groups have an underlying inner attribute that differentiates them from other racial groups.
–> fosters stereotypical beliefs and racist behavior.
Creativity in problem solving was measured in a group that got an essentenlist text as priming or a nonessential priming.
- essentialist group scored higher in closed mindedness and less participants could solve the creativity problem.
–> essentialism hinders creativity
Psychological essentialism
Genetic essentialism
- generalizes the perception of ethnic groups
- essence gives rise to entities–> the only nature argument
Genes are everything that matters.
There is no nurturing and therefore changing of your character or your way of being.
Working Memory rule based categorization system.
three steps:
1) selective attention to each item
2) determining whether the value matches the feature specified in the rule
3) outcome of stage two is identified in order to categorize the object.
Activation in the brain:
- left hemisphere
inferior parietal cortex,
parietal occipital cortex
Selective attention:
Right prefrontal cortex
Do humans belong with nature? ( Levin 2013)
Human, animals, nature categorisation task.
children at and under the age of 10 + adults got the exercise to categorize humans animals and plants after being primed with the exercise to either describe an experience in nature or talk abstractly about nature.
Results:
Children in the younger stages of development are more likely to group humans with nature than adults or older children.
young children grouped more to nature in the self expressive priming, than the abstract one.
Adults grouped more to nature in the abstract condition.
WM based categorisation
rule based categorisation:
- active manipulation
- represents active information that is represented explicitly
prefrontal cortex and posterior parietal areas
Explicit Long term memory based categorization
- passive longterm storage in the medial temporal lobe
–> medial temporal lobe is active as well as the the parietal areas and the perceptual areas.
- Similarity based categorization
–> comparing the previously stored items to a prototype.
implicit long term memory based categorization
- retrieval without awareness
- perceptual priming categorization
- stimuli that can be categorized through the implicit ltm are difficult to verbalize.
- patients that have damage on the e ltm can still perform tasks with the i ltm.
food waste study
Hingston et al
- relation to misformed food is dependent on the experience a person has made before.
- direct contact with the fruit or vegetable ( buying it directly on a farm)
–> prove for the prototypical categorisation theory.
–> the consumers living in rural areas have more contact to misshaped food there fore their prototype of e.g. a carrot changes.
study cultural blindness vs. emphasizing ethnic differences (Wilton & Good)
- studies came to an ironic outcome, that emphasizing ethnic and cultural differences does actually reinforce the belief in fixed biological characteristics that underpin them.
Applying the categorization theories to evolution
- amimals and humans use familiy resemblance for categorizing
- and prototypes
- bad memory of exemplars–> takes up a lot of storage
example: monkey eagle scream–> categorisation of the eagle
