Week 13: Cognitive Development Flashcards
Learning objectives:
Understand the problems with attempting to define categories.
Understand typicality and fuzzy category boundaries.
Learn about theories of the mental representation of concepts.
Learn how knowledge may influence concept learning.
Define category
A set of entities that are equivalent in some way. Usually, the items are similar to one another.
Define concpepts
The mental representation of a category
categories are well-defined by these two parts
- Provides the necessary features for category membership: What must objects have in order to be in it?
- Those features must be jointly sufficient for membership: If an object has those features, then it is in the category.
Ex. if I defined a dog as a four-legged animal that barks, this would mean that every dog is four-legged, an animal, and barks, and also that anything that has all those properties is a dog.
Hampton (1979)
Asked subjects to judge whether a number of items were in different categories. He did not find that items were either clear members or clear nonmembers. Instead, he found many items that were just barely considered category members and others that were just barely not members, with much disagreement among subjects.
Fuzzy Categories borderline members
Not clearly in or clearly out of the category.
McCloskey and Glucksberg (1978)
In this study, it was found that after a span of two weeks, people changed their minds about borderline items (up to 22 percent of the time)
People disagree not only with others, but also themselves about borderline items
Define Typicality
The difference in “goodness” of category members, ranging from the most typical (the prototype) to borderline members.
Ex. Birds
Typical - robin
Atypical - penguin
Influences of Typicality on Cognition (6)
Typical items are judged category members more often (Hamption, 1979).
Speed of categorization is faster for typical items (Rips, Shoben, & Smith, 1973).
Typical members are learned before atypical ones (Rosh &Mervis).
Learning a category is easier if typical examples are provided (Mervis & Pani).
In language comprehension, references to typical members are understood more easily (Garrod & Sanford, 1977).
In language production, people tend to say typical items before atypical ones (e.g., “apples and lemons rather than “lemons and apples”) (Onishi, Murphy, & Bock, 2008).
Rosch and Mervis’s (1975) family resemblance theory
Items are likely to be typical if they (a) have features that are frequent in the category and (b) do not have features frequent in other categories.
Robins are small flying birds that sing, live in nests in trees, migrate in winter, hop around on your lawn, and so on. Most of these properties are found in many other birds.
In contrast, penguins do not fly, do not sing, do not live in nests or in trees, do not hop around on your lawn. Furthermore, they have properties that are common in other categories, such as swimming expertly and having wings that look and act like fins. These properties are more often found in fish than in birds.
basic level of categorization
(father of the word tree)
&
Preferred level
The neutral, preferred category for a given object, at an intermediate level of specificity.
The preferred level is not (only) based on how different categories are in the world, but that people’s knowledge and interest in the categories has an important effect.
prototype theory
People have a summary representation of the category, a mental description that is meant to apply to the category as a whole. (The significance of the summary will become apparent when the next theory is described.) This description can be represented as a set of weighted features (Smith & Medin, 1981). The features are weighted by their frequency in the category. For the category of birds, having wings and feathers would have a very high weight; eating worms would have a lower weight; living in Antarctica would have a lower weight still, but not zero, as some birds do live there.
exemplar theory
denies that there is a summary representation. Instead, the theory claims that your concept of vegetables is remembered examples of vegetables you have seen. This could of course be hundreds or thousands of exemplars over the course of your life, though we don’t know for sure how many exemplars you actually remember. How does this theory explain classification? When you see an object, you (unconsciously) compare it to the exemplars in your memory, and you judge how similar it is to exemplars in different categories. For example, if you see some object on your plate and want to identify it, it will probably activate memories of vegetables, meats, fruit, and so on. In order to categorize this object, you calculate how similar it is to each exemplar in your memory. These similarity scores are added up for each category. Perhaps the object is very similar to a large number of vegetable exemplars, moderately similar to a few fruit, and only minimally similar to some exemplars of meat you remember. These similarity scores are compared, and the category with the highest score is chosen.
psychological essentialism(Gelman, 2003; Medin & Ortony, 1989
The belief that members of a category have an unseen property that causes them to be in the category and to have the properties associated with it.
Signs of essentialism (3)
(a) objects are believed to be either in or out of the category, with no in-between;
(b) resistance to change of category membership or of properties connected to the essence; and
(c) for living things, the essence is passed on to progeny.
Learning Objectives:
Be able to identify and describe the main areas of cognitive development.
Be able to describe major theories of cognitive development and what distinguishes them.
Understand how nature and nurture work together to produce cognitive development.
Understand why cognitive development is sometimes viewed as discontinuous and sometimes as continuous.
Know some ways in which research on cognitive development is being used to improve education.
Cognitive development
refers to the development of thinking across the lifespan.
Cognitive development is about change. Children’s thinking changes in dramatic and surprising ways.
Piaget’s stage theory
The theory that development occurs through a sequence of discontinuous stages: the sensorimotor, preoperational, concrete operational, and formal operational stages.
Sociocultural theories
Theory founded in large part by Lev Vygotsky emphasizes how other people and the attitudes, values, and beliefs of the surrounding culture influence children’s development.
Information processing theories
Theories that focus on describing the cognitive processes that underlie thinking at any one age and cognitive growth over time.
two main questions in Cognitive development theories
(1) How do nature and nurture interact to produce cognitive development?
(2) Does cognitive development progress through qualitatively distinct stages?
Nature
The genes that children bring with them to life and that influence all aspects of their development.
Nurture
The environments, starting with the womb, that influence all aspects of children’s development.
depth perception
The ability to actively perceive the distance from oneself of objects in the environment.
quantitative changes
Gradual, incremental change, as in the growth of a pine tree’s girth.
