

Chapter 1

Behaviorism: A movement in psychology which assumes that it is possible to explain psychological phenomena by focusing only on behavior and the environment in which it occurs, and without reference to the mind.

Biological preparedness: A genetically determined readiness to learn specific skills, such as how to walk.

Conditioning: Controlling behavior by manipulating rewards and various stimuli within the environment.

Deep structure: An innate grammatical structuring of language that is both universal among humans and unique to humans as a species.

Egocentrism: Difficulty taking on board another person's perspective.

Erogenous zone: An area of the body that has sexual focus.

Ethology: The study of animals in their natural habitat.

Innate: An ability or trait that is with us from birth.

Maturational unfolding: A genetically determined developmental progression.

Nature–nurture debate: A debate on whether abilities and other characteristics are largely the product of our genetic inheritance (nature) or largely the product of our environment and experiences (nurture).

Reinforcement: Any stimulus that, when following behavior, increases the probability that the organism will emit the same behavior in the future.

Chapter 2

Autism: A developmental disorder affecting about one per hundred of the population. Those with the disorder are impaired in socially connecting with other people.

Executive functions: A process or set of processes located in the frontal lobes of the brain involved in controlling one’s own behavior and one’s own mental processes.

Experimental noise: Sets of data arising from psychological research seldom or never are pure measures of the phenomenon of interest. Usually, the set of data is composed of a mixture of the thing we want to measure plus other factors that influence the way that research participants (e.g. children) respond. The aspect of the data that is caused by these other unwanted factors is called “experimental noise.”

Intellectual realism: The phenomenon of children drawing what they know rather than what they see.

Mirror neuron hypothesis: A hypothesis stating that when you observe another person doing something, the same brain areas will be active in you the observer as in the other person doing the action.

Motor cortex: A region of the frontal lobes of the outer cortex of the brain that is responsible for volitional control of the muscles.

Nonconserving answer: Wrongly judging that quantity has changed just because there is a superficial change in appearance.

Performative bias: The tendency to respond to a question with an action instead of replying verbally.

Pragmatic: The form language takes when used in a natural context.

Yes bias: A bias to answer all questions that require an answer of either “yes” or “no” in the affirmative.

Chapter 3

Accommodation: Modifying a scheme to adapt it to a new application.

Assimilation: Applying an existing scheme to a novel task.

Coordination of schemes: Combining schemes to carry out an elaborate task, such as driving a car.

Decenter: To broaden attention to the various facets of a problem instead of fixating on just one.

Imaginary audience: A fantasy that people are watching your actions with great intrigue.

Mental imagery: The ability to imagine the existence of things even when they are not directly accessible to the senses.

Object permanence: Understanding that things in the world continue to exist even when you can't sense them directly.

Operational intelligence: The process of solving a problem by working through logical principles.

Personal fable: A fantasy that you have a privileged position on earth and that you are being watched over and protected by a supernatural being.

Schemes: A mental operation that guides action or allows us to work through a problem in a principled way.

Solipsism: Failure to distinguish between yourself and the rest of the universe.

Chapter 4

Confirmation bias: Inappropriately seeking evidence in support of a hypothesis instead of seeking evidence that might falsify a hypothesis.

Human sense: A term coined by Margaret Donaldson. A task that makes no human sense is one in which children misinterpret the purpose of the experimenter's questions.

Inference by elimination: Finding the correct answer by ruling out alternatives.

Level 1 perspective-taking: Understanding that an obstacle prevents another person seeing what you can see.

Level 2 perspective-taking: Understanding how an object looks from a vantage point other than your own.

Private speech: Privately talking through a problem in order to arrive at a solution.

Scaffolding: Support provided by adults (or more competent other individuals) that helps children to construct knowledge.

Selection task: A task devised by Wason and Johnson-Laird that reveals illogical reasoning in adults.

Size constancy: A perceptual mechanism that enables us to appreciate that an object remains the same size even though it appears smaller as it recedes into the distance.

Social constructivism: A theory espoused by Vygotsky that emphasizes the role of adults (or other more competent individuals) in supporting the child to construct knowledge.

Syllogism: All Xs are Ys. John is an X, therefore he must also be a Y.

Zone of proximal development: A period in which the child is cognitively ready to acquire a certain kind of new concept.

Chapter 5

Appearance–reality test: A task in which an object has deceptive appearance, as in a sponge painted to look like a rock.

Deceptive box task: A test of false belief in which a familiar container, such as a Smarties™ tube, contains something other than its normal content.

Hindsight bias: Believing that you had known something all along even though in fact you only made the discovery recently.

Mailing procedure: A false belief test in which children mail a picture of the false belief into a mailbox before learning that the belief is actually false; the mailed picture serves as an aide memoir to the false belief.

State change: A task employing a box that has characteristic content (e.g. Smarties™ tube) in which the normal content exists to begin with but is then replaced as the child watches with an atypical content.

Unexpected transfer test: A test of false belief in which participants observe that an object moves from location A to location B without a protagonist's knowledge.

Chapter 6

Alexia: Dyslexia that is acquired, perhaps during adulthood, following neurological damage caused by accident or illness.

Asperger's syndrome: Having the features of autism but in the absence of language delay.

Brain plasticity: The capacity for unaffected parts of the brain to assume the activities of damaged parts of the brain.

Cerebellum: A structure located at the rear of the brain that has a role in generating fine movements.

DSM: Diagnostic and Statistical Manual of the American Psychiatric Association. This manual lists features of various psychological disorders.

Echolalia: Meaninglessly repeating words or phrases that you just heard.

Executive functions: A process or set of processes located in the frontal lobes of the brain involved in controlling one's own behavior and one's own mental processes.

Frontal syndrome: A condition caused by damage to the frontal lobes of the brain, associated with disinhibition and lack of social sensitivity.

Gaze following: The ability to follow another person's direction of gaze and to locate and fixate on the object being looked at by the other person. Children normally become highly effective in doing this from 18 months.

High functioning autism: Autism with measured intelligence in the normal range.

Hyperlexia: An unusually large vocabulary, relative to developmental level, especially on a particular topic (e.g. species of dinosaurs).

Obsessive-compulsive disorder: A clinical disorder associated with compulsive ritualistic behavior and obsessive cleanliness such as incessant hand-washing and aversion to touching things that have been touched by another person (e.g. coins).

Placebo: An inert substance that has no active ingredient.

Pronoun reversals: Confusion over whether I should be denoted as I or you.

Chapter 7


Capture by meaning: A tendency to overlook fine detail brought about by attention to the global meaning of a stimulus or event.

Sally–Ann task: A simplified version of the unexpected transfer test of false belief.

Specificity: A characteristic is specific to a disorder providing that individuals with a different disorder don't have the same characteristic.

The theory of mind hypothesis of autism: A hypothesis positing that autism is explained as impaired theory of mind.

Triad of impairments: Impairments in socialization, communication, and imagination, which are characteristic of autism.

Universal: A characteristic is universal to a disorder if all individuals diagnosed have the characteristic in question.

Windows task: A task devised to reveal the kind of mental inflexibility in individuals with autism that could explain their difficulty with tests of false belief.

Wisconsin Card Sort Test: A test devised to reveal mental inflexibility in individuals who have suffered damage to the frontal lobes of the brain.

Chapter 8

Cardinal number: The number that determines the size of a set.

Continuous and discrete variables: Variables that could take on any value in a range are continuous, whereas a discrete variable can only take on certain values such as whole numbers.

Habituation paradigms: Infants are shown a stimulus until they are bored and look away, when a test stimulus is shown. A display of renewed interest shows that infants perceive this as a different stimulus.

Numerical relations: Comparison of the quantity (magnitude or multitude) between things, where one can be greater than or less than the other.

Numerosity: The number of objects in a set.

Violation-of-expectation: Understanding of principles and concepts drives expectations about unfolding of events. When babies are presented with unexpected (i.e. impossible) events and look at those longer than at expected (possible) events it indicates that they understand the principle or concept.

Chapter 9


Viewer independent: The true dimensions and properties of an object, and not just those that appear from a specific vantage point.

Chapter 10

Binocular parallax: Discrepancy in information received by each eye that varies by degree according to how far away the object of focus happens to be.

Carpentered environment: An environment containing straight lines and 90-degree angles, which is typical in industrialized cultures.

Figure and ground: Objects in the foreground are interpreted as partly or fully occluding objects in the background.

Inter-modal mapping: Mapping from one modality (e.g. information acquired through visual perception) to another (e.g. making a facial expression).

Motion parallax: Discrepancy in apparent movement as we shift vantage point of near and distant objects, depending on the relative distance of those objects.

Prefer to look—preferential looking: Babies prefer to look at novel stimuli, which allows researchers to identify what kinds of things babies do and do not interpret as being novel.

Shape constancy: A perceptual mechanism that enables us to appreciate that an object remains the same shape even though it looks different as we take up different vantage points.

Visual cliff: Apparatus designed by Gibson and Walk that formed an apparent precipice for the purpose of testing perception of depth in babies.

Chapter 11

Crystalized intelligence: A fundamental factor in intelligence that represents the accumulated knowledge of an individual.

Dizygotic twins: Fraternal twins who share 50% of genetic material because they develop from separate eggs.

Fluid intelligence: A fundamental factor in intelligence that represents the ability to think and reason on your feet.

Flynn effect: The increase in IQ scores from one generation to the other, which averages about 3 points per generation and cannot be explained by an increase in intelligence in the population.

g: General intelligence is the concept of intelligence as a single factor that influences all cognitive functioning.

IQ: The intelligence quotient is an index of an individual's intelligence score. It falls on a normal distribution with a mean of 100.

Monozygotic twins: Identical twins who share 100% of genetic material because they develop from a single egg and sperm.

Raven's Standard Progressive Matrices: A nonverbal intelligence test requiring analogous reasoning on geometric shapes and patterns, which was designed to be culture-free.

Stanford–Binet test: The modern version of the first IQ tests, testing verbal and nonverbal items.

WASI: The Wechsler Adult Scale of Intelligence is the adult version of the WISC and contains the same components.

WISC: The Wechsler Intelligence Scale for children is one of the most widely used IQ tests, split into a verbal and a performance component, which are combined to give a full-scale IQ.

Chapter 12

Connectionism: The idea that cognitive processes can be explained as a result of the interplay between several simple interconnected units.


Grammar: A set of rules governing language.

Holophrase: Using a single word, often in combination with a gesture, to express a more complex idea.

Infant-directed talk: A special style of speech used when talking to infants.

Infinite generativity: The ability to form an unlimited number of utterances from a limited number of words.

Joint attention: The process of intentionally sharing the experience of observing an object or event through the use of pointing gestures or following gaze.

LAD: The language acquisition device is an innate device for acquiring language.

LASS: The language acquisition support system stresses the contribution of the home environment and culture in children's language learning.

Morpheme: Is made up of one or more phonemes and is the smallest unit of meaning in language.

Overextension: Using a word in a broader context than is appropriate.

Overgeneralization: At one stage in language development children apply the rule for forming the past tense inappropriately to irregular words.

Phoneme: The smallest unit of sound making up language.

Pragmatic rules: A set of rules that dictates how language is used to communicate; an understanding of pragmatics is often essential to understand what the speaker means.


Surface structure: The specific grammatical features of a specific language.

Syntax: A set of rules that governs how words can be combined into phrases and sentences.

Telegraphic speech: An early style of language, resembling the efficient use of language in telegrams, in which children use few words to get their point across.

Universal grammar: A set of formal structural rules common to all languages.

Usage-based language theory: The idea that there is no specific cognitive module for language learning, but that children learn both vocabulary and rules of language through using it in trying to communicate with others.

Vocabulary: A set of words from a specific language known to a person.

Chapter 13

Ambiguous message: An utterance that fails to specify a single item uniquely.

Communicative value: The effectiveness of a message in informing a listener.

Egocentric speech: Speaking in a way that does not respect the informational needs of a listener.

Say–mean distinction: Understanding that what people mean might differ in subtle ways from what they actually say.

Chapter 14

Adult attachment interview: A systematic interview designed for use with adults to probe the quality of the relationship they had with their primary caregiver when they were children.

Cycle of abuse: Adults who abuse children are likely to have been victims of abuse when they were children.

Mind-minded: A parent who is attuned to her child on a psychological level and not just in terms of physical needs.

Partial deprivation: Insufficient contact between mother and baby that brings about negative consequences for the baby's emotional development.

Separation anxiety: A state of anxiety experienced by a baby when her mother leaves the room.

Social referencing: Babies periodically look at their mother's face for signs of encouragement or anxiety, especially when they are in a novel situation.

Strange situation: A task designed to reveal both separation anxiety and the quality of attachment between mother and baby.

Chapter 15

“Feel good” principle: A kind of morality that says an act is justifiable if it yielded positive benefits for the person carrying out the act.

Longitudinal study: A study conducted over a long period of time (months or even years) with the same participants in an attempt to document changes that occur during development.

Moral dilemma: A dilemma arising from conflict between two moral codes, for example acting in accordance with the law and acting in accordance with one’s conscience.

Moral realist: A person who judges moral acts according to the physical consequences of the act rather than according to the intention behind the act.

Moral subjectivist: A person who judges moral acts according to the intention behind the act rather than according to the physical consequences of the act.

Social convention: A code of behavior that is based on convention rather than principle.

Chapter 16

Attention-seeking behavior: Misbehavior that attracts a punitive response from an authority figure.

Hostile aggression: Aggression that is not instrumental but rather is motivated in an attempt to harm another person just for the sake of it.

Instrumental aggression: Aggression that is a means to achieve a specific end.

Psychological rejection: Being shunned and ignored by peers and other individuals.

Sensitive period: A period in development when learning of a certain kind readily takes place.