Samenvattingen Literature DLB

Week 17

Siegler Chapter 1: An introduction to child development

Zie samenvatting blz 36 en 37

Week 18

Siegler Chapter 2: Prenatal Development and the Newborn Period

Prenatal development

• Nature and nurture combine forces in prenatal development. Much of this development is generated by the fetus itself, making the fetus an active player in its own progress. Substantial continuity exists between what goes on before and after birth in that infants demonstrate the effects of what has happened tot hem in the womb.
• Prenatal development begins at the cellular level with conception, the union of an egg from the mother and a sperm from the father to form a single-celled zygote. The zygote multiplies and divides on its way through a fallopian tube.
  
  • Epigenesis: the emergence of new structures and functions in the course of development
  • Gametes (germ cells): reproductive cells – egg and sperm – that contain only half the genetic material of all the other cells in the body
  • Meiosis: cell division that produces gametes
  • Conception: the union of an egg from the mother and a sperm from the father
  • Zygote: a fertilized egg cell
  • Embryo: the developing orgniasm from the 3rd to 8th week of prenatal development
  • Fetus: the developing organism from the 9th week to birth
  • Mitosis: cell division that results in two identical cells
• The zygote undergoes the processes of cell division, cell migration, cell differentation, and cell death. These processes continue throughout prenatal development.
  
  • Embyronic stem cells: embryonic cells, which can develop into any type of body cell
  • Apoptosis: gentically programmed cell death
  • Identical (monozygotic) twins: twins that result form the splitting in half of the zygote, resulting in each of the two resulting zygotes having exactly the same set of genes
  • Fraternal (dizyotic) twins: twins that result when two eggs happen tob e released into the fallopian tube at the same time and are fertilized by two different sperm; fraternal twins have only half their genes in common
• When the zygote becomes implanted on the uterine wall, it becomes an embryo. From that point, it is dependent on the mother to obtain nourishment and oxygen and to get rid of waste products through the placenta.
  
  • Neural tube: a groove formed in the top layer of differentiated cells in the embryo that eventually becomes the brain and spinal cord
  • Amniotic sac: a transparent, fluid-filled membrane that surrounds and protects the fetus
  • Placenta: a suport organ fort he fetus; it keeps the circulatory systems of the fetus and mother separate, but a semipermeable membrane permits the exchange of some materials between them (oxygen and nutrients from mother to fetus, and carbon dioxide and waste products from fetus to mother)
  • Umbilical cord: a tube containing the blood vessels connecting the fetus and the placenta
  • Cephalocaudal development: the pattern of growth in which areas near the head develop earlier than areas farther from the head
• Fetal behaviour begins 5 or 6 weeks after conception with simple movements, undetected by the mother, that become increasingly complex and organized into patterns. Later, the fetus practices behaviors vital to independent living, including swallowing and a form of intrauterine ‘breathing’.
  
  • Phylogenetic continuity: the idea that because of our common evolutionary history, humans share many characteristics, behaviors, and developmental processes with non-human animals, especially mammals
• The fetus experiences a wealth of stimulation both from within the womb and from the external environment. The fetus learns from this experience, as demonstrated by studies showing that both fetuses and newborns can discriminate between familiar and novel sounds, especially in speech, and exhibit persistent taste preferences developed in the womb.
  
  • Habituation: a simple form of learning that involves a decrease in response to repeated or continued stimulation
  • Dishabituation: the introduction of a new stimulus rekindles interest following habituation to a repeated stimulus

Hazards to prenatal development

• There are many hazards to prenatal development. The most common fate of fertilized egg is spontaneous abortion (miscarriage).
• A wide range of environmental factors can be hazardous to prenatal development. These include teratogens from the external world and certain material characteristics, such as age, nutritional status, physical health, behavior (espacially the use of legal or illegal drugs), and emotional state.
  
  • Teratogen: an external agenet that can cause damage or death during prenatal development
  • Sensitive period: the period of time during which a developing organism is most sensitive tot he effects of external factors
  • Dose-response relation: a relation in which the effect of exposure to an element increases with the extent of exposure (prenatally, the more exposure a fetus has to a potential teratogen, the more severe its effect is likely to be)
  • Sudden infant death syndrom (SIDS): the sudden, unexpected death of an infant less than 1 year of age that has no identifiable cause
  • Fetal alchohol spectrum disorder (FASD): the harmful effects of maternal alcohol consumption on a developing fetus. Fetal alcohol syndrom (FAS)involves a range of effects, including facial deformtieis, intellectual dissabilities, attention problems, hyperactivity, and other defects. Fetal alcohol effects (FAE) is a term used for individuals who show some, but not all, of the standard effects of FAS.

The birth experience

• Approximately 38 weeks after conception, the baby is ready tob e born. Usually, the behavior of the the fetus helps to initiate the birth process.
• Being squeezed through the birth canal has several beneficial effects on the newborn, including preparing the infant to take his or her first breath.
• Cultural practices surrounding childbirth vary greatly and are in part related tot he goals and values emphasized by the culture.

The newborn infant

• Newborns’ states of arousal range from deep sleep to active crying.
  • Rapid eye movement (REM) sleep: an active sleep state characterized by quick, jerky eye movements under closed lids and associated with dreaming in adults
  • Non-REM sleep: a quiet or deep sleep state characterized by the absence of motor activity or eye movements and more regular, slow brain waves, breathing and heart rate
• The amount of time infants spend in the different arousal states varies greatly, both across individuals and across cultures.
• REM sleep seems to compensate fort he lack of visual stimulation that results from the darkness of the womb, and fort he fact that newborns spend much of their time with their eyes shut, asleep.
• The sound of a baby crying can be very aversive, and adults employ many strategries to soothe distressed infants.
  
  • Swaddling: a soothing technique, used in many cultures, that involves wrapping a baby tightly in cloths or a blanket
  • Colic: excessive, inconsolable crying by a young infant for no apparent reason
• The infant mortality rate in the US is high relative tot hat of other developed counties. It is much higher for babies born to low-SES parents.
  
  • Apgar score: method for evaluating the health of newborn immediately following birth based on skin tone, pulse rate, facial response, arm and leg activity, and breathing
  • Infant mortality: death during the first year after birth
• Infants born weighing less than 5,5 pounds (2500 grams) are referred to as being low of birth weight. LBW infants are at risk for a variety of developmental problems, and the lower the birth weight, the greater the risk of lasting difficulties.
  
  • Low birth weight (LBW): a birth weight of less than 5,5 pounds (2500 grams)
  • Premature: any child born at 35 weeks after conception or earlier (as opposed tot he normal term of 38 weeks)
  • Small for gestational age: babies who weigh substantially less than is normal for whatever their gestational age
• A variety of intervention programs have been designed to improve the course of development of LBW babies, encompassing time in the hospital as well as after the infant returns home.
• The multiple-risk model refers to the fact that infants with a number of risk factors have a heightened likelihood of continued developmental problems. Poverty is a particularly insidious risk to development, in part because it is associated with numerous negative factors.
• Some children display resilience even in the face of substantial challenges. Resilience seems to result form certain personal characteristics and from repsonsive care from someone.
  
  • Developmental resilience: succesful development in spite of multiple and seemingly overwhelming developmental hazards

Siegler Chapter 3 (96-104): Biology and behaviour

Brain development

• Neurons, the basic units of the brain’s informational system, transmit information between the brain and body via electrical signals. The brain’s cortex is composed of several major areas, or lobes, specialized for different functions.
  • Neurons: cells that are specialized for sending and receiving messages between the barin and all parts of the body, as well as wihtin the brain itself
  • Cell body: a component of the neuron that contains the basic biological material that keeps the neuron functioning
  • Dendrites: neural fibers that receive input for other cells and conduct it towards the cell body in the form of electrical impulses
  • Axons: neural fibers that conduct electrical signal away from the cell body to connections with other neurons
  • Synapses: microscopic junctions between the axon terminal of one neuron and the dendritic branches or cell body to another
  • Glial cells: cells in the brain that provide a variety of critical supportive functions
  • Myelin sheath: a fatty sheath that forms around certain axons in the body and increases the speed and efficiency of information transmission
  • Cerebral cortex: the ‘gray matter’ of the brain, consisting of four distinct lobes
  • Occipital lobe: major area of the cortex that is primarly involved in processing visual information
  • Temporal lobe: major area of the cortex that is associated with speech and language, music and emotional information
  • Parietal lobe: major area of the cortex that is associated with spatial processing and sensory information integration
  • Frontal lobe: major area of the cortex that is associated with working memory and cognitive control
  • Association areas: parts of the brain that lie between the major sensory and motor areas and that process and intergrate input from those areas
  • Cerebral hemispheres: the two halves of the cortex
  • Corpus callosum: a dense tract of nerve fibers that enable the two hemispherers of the brain to communicate
  • Cerebral lateralization: the specializationi of the hemispheres of the brain for different modes of processing
• Brain development involves several processes, beginning with neurogenesis and differentiation of neurons. In synaptogenesis, an enormous profusion of connections among neurons is generated, starting prenatally and continuing for the first few years after birth. Through synaptic pruning, excess connections among neurons are eliminated. Myelination, another important process for neural processing, begins before birth and continues through adulthood.
  
  • Neurogenesis: the proliferation of neurons through cell division
  • Arborization: formation of new dendritic trees and branches
  • Spines: formations on the dendrites of neurons that increase the dendrites’ capcacity to form connections with other neurons
  • Myelination: the formation of myelin (a fatty sheath) around the axons fo neurons that speeds and increases information processing abilities
  • Synaptogenesis: the process by which neurons form synapses with other neurons, resulting in trillions of connections
  • Synpatic pruning: th enormal developmental process through which synapses that are rarely activated are eliminated
• Experience plays a crucial role in the strenghtening or elimination of synapses and hence in the normal wiring of the brain. The fine-tuning of the brian involves experience-expectant processes, in which existing synapses are preserved as a function of stimulation that virtually every human encounters, and experience-dependent processes, in which new connections are formed as a function of experience and learning.
  
  • Plasticity: the capacity of the brain to be affected by experience
  • Experience-expectant plasticity: the process through which the normal wiring of the brain occurs in part as a result of species-typical experiences
  • Experience-dependent: the process through which neural connections are created and reorganized throughout life as a function of an individual’s experiences
• Plasticity makes it possible in certain circumstances fort he brain to rewire itself in response to damage. It also makes the developing brain vulnerable tot he absence of stimulation at sensitive periods in development. The ability of the brain t orecover from injury depends on the age of the child.

Week 19

Siegler Chapter 3: Biology and behaviour

Nature and Nurture

• The starting point for development is the genotype – the genes inherited at conception from one’s parents. Only some of those genes are epressed in the phenotype , one’s observable characteristics. Whether some genes are expressed at all is a function of dominance patterns. Most traits studied by developmental scientists are influence by multiple genes.
  • Genome: the complete set of DNA of any organism, including all of its genes
  • Genotype: the genetic material an individual inherits
  • Phenotype: the observable expression of the genotype, including both body characteristics and behavior
  • Environment: every aspect of individuals and their surroundings other than genes
• The eventual outcome of a given genotype is always contingent on the environment in which it develops. Parents and their behavior toward their children – which is influenced by the parents’ own genotypes – are a salient part of the children’s environment. Similarly, the child’s development is influenced by the aspects of the environment he or she seeks out and the different responses the child’s characteristics and behavior evoke from other people.
  
  • Parents’ genotype-child’s genotype
    
    • Human heredity
      
      • Chromosomes: molecules of DNA that transmit genetic information; chromosomes are made up of DNA
      • DNA: molecules that carry all the biochemical instructions involved in the formation and functioning of an organism
      • Genes: sections of chromosomes that are the basic unit of heredity in all living things
    • Genetic diversity and individual differences
      
      • Crossing over: the process by which sections of DNA switch from one chromosome tot he other; crossing over promotes variability among individuals
      • Mutation: a change in a section of DNA
      • Sex chromosomes: the chromosomes (X and Y) that determine an individual’s designated sex at birth
      • Endophenotypes: intermediate phenotypes, including the brain and nervous systems, that do not involve overt behavior
      • Regulator genes: genest hat control the activity of other genes
  • Child’s genotype-child’s phenotype
    
    • Endophenotype à intermediate phenotypes, including the brain and nervous systems, that do not involve overt behavior
    • Gene expression: developmental changes
      
      • Regulator genes: genest hat control the activity of other genes
    • Gene expression: dominance patterns
      
      • Alleles: two or more different forms of a gene
      • Dominant allele: the allele that, if present, gets expressed
      • Recessive allele: the allele that is not expressed if a dominant allele is present
      • Homozygous: having two of the same allele for a trait
      • Heterozygous: having two different alleles for a trait
      • Polygenic inheritance: inheritance pattern in which traits are governed by more than one gene
      • Phenylketonuria (PKU): a disorder related to a defective recessive gene on chromosome 12 that prevents metabolism of the animo acid phenylalanine
  • Child’s phenotype-child’s environment
    
    • Each child evokes certain kinds of responses from others.
    • Children also create their own environments by actively selecting surroundings and experiences that match their interests and personalities
  • Child’s environment-child’s genotypes
• Epigenetic effects – the switching on and off of genes – underlies many aspects of development and individual differences. This process is affected by experience via methylation.
  
  • Epigenetics: the study of stable changes in gene expression that are mediated by the environment

Behavior genetics

• Behavior genetics is concerned with the joint influence of genetic and environmental factors on behavior. Quantative behavior genetics use a variety of family-study designs to generate heritability estimates, examining the relative contributions of heredity and environment for individual differences for a range of traits and behaviors in a population. Molecular behavior genetics approaches permit the field to move beyond family designs to investigate patterns of genes across large groups of people.
  • Behavior genetics: the science concerned wiht how variation in behavior and development results from the combination of genetic and environmental factors
  • Heritable: refers to characterstics or traits that are genetically transmitted
  • Heritability: a statiscal estimate of the proportion of the measured variance on a trait among individuals in a given population that is attributable to genetic differences among those individuals
    
    • Heritability applies only to populations
    • A heritability estimate applies only to a particular populations living in a particular environment
    • Heritability estimates can change as a function of developmental factors
    • High heritability does not imply immutability

Brain development à zie week 18

The body: physical growth and development

• Humans undergo a particularly prolonged period of physical growth, during which growth is uneven, proceeding more rapidly early in life and in adolescence. Secular trends have been observed in increases in average weight and height.
  • Secular trends: marked changes in physical development that have occurred over generations
• Food preferences begin with innate responses by newborns to basic tastes, but additional preferences develop as a result of experience. Problems with the regulation of eating are evident in the US, where an epidemic of obesity is clearly related to both environmental and genetic factors.
• Inadequate nutrition is closely associated with poverty, and it leads to a variety of behavorial and physical problems in virtually every aspect of the child’s life. Prevention of undernutrition is needed to enable millions of children to develop normal brains and bodies. Vaccines help to protect vulnerable infants and children from a range of diseases. Highly publicized claims about links between autism and vaccines are based on falsified data;  vaccines do not cause autism.

Siegler Chapter 5 perception, action and learning in infancy (pp.159-176)

Perception

• Newborn’s visul systems are relatively immature, with poor acuity, low contrast sensitivity, and minimal color vision. They begin visually scanning the world minutes after birth and show  preferences for strongly contrasted patterns, including faces.
  • sensation: the processing of basic information from the external world via receptors in the sense organs (eyes, ears, skin, etc.) and brain
  • Perception: the process of organizing and interpreting sensory information
  • Preferential-looking technique: a method for studying visual attention to infants that involves showing infants two images simultaneously to see if the infants prefer one over the other (indexed by longer looking)
  • Visual acuity: the sharpness and clarity of vision
  • Contrast sensitiviy: the ability to detect differences in light and dark areas in a visual pattern
  • Cone cells: light-sensitive neurons that are highly concentrated in the fovea (the central region of the retina)
• Some visual abilities, including perception of constant size and shape, are present at birth; others develop rapidly over the first year. Binocular vision emerges at about 4 months of age, and the ability to identify object boundaries (i.e., object segregation) is also present at that age. By 7 months, infants are sensitive to a variety of monocular, or pictorial, depth cues.
  
  • Smooth pursuit eye movements: visual behavior in which the viewer’s gaze shifts at the same rate and angle as a moving object
  • Perceptual consistency: the perception of objects as being of constant size, shape, color, etc., in spite of physical differences in the retinal image of the object
  • Object segregation: the identification of separate objects in a visual array
  • Violaton-of-expectancy: a procedure used to study infant cognition in which infants are shown an event that should evoke surprise or interest i fit goes  against something the infant knows
• Contrary to Piaget’s beliefs about object permanence, experiments suggest that young infants can remember objects that are no longer visible.
  
  • Optical expansion: a depth cue in which an object occludes increasingly more of the background, indicating that the object is approaching
  • Binocular disparity: the difference between the retinal image of an object in each eye that results in two slightly different signals being sent tot he brain
  • Stereopsis: the process by which the visual cortex combines the differing neural signals caused by binocular disparity, resulting in the perception of depth
  • Monocular depth (or pictoral) cues: the perceptual cues of depth (such as relative size and interposiiton) that can be perceived by one eye alone
• The auditory system is comparatively well developed at birth, and newborns will turn their head to localize a sound. Young infant’s remarkable proficiency at perceiving pattern in auditoryt stimulation underlies thier sensitivity to musical structure.
  
  • Auditory localization: perception of the location in space of a sound source
  • Perceptual narrowing: developmental changes in which experience fine-tunes the perceptual system
• Thourgh active touching, using both mouth and hands, infants explore and learn about themselves and their environment.
• Research on intermodal perception has revealed taht from very early on, infants integrate information from different senses.
  
  • Intermodal perception: the combining of information from two or more sensory systems
  • Reflexes: fixed patterns of action that occur in response to particular stimulation

Week 20

Siegler Ch4 theories of cognitive development

Piaget’s theory

• Among the reasons fort he longevity of Piaget’s theory are that it vivdly conveys the flavor of children’s thinking at different ages, extends across a broad range of ages and content areas, and provides many fascinating and surprising observations of children’s thinking.
• Piaget’s theory is often labeled constructivist because it depicts children as actively constructing knowledge for themselves in response tot heir experience. The theory posits that children learn through tow porceses that are present from birth – assimilation and accomodation – and that the contribution of these processes is balanced through a third process, equilibration. These processes produce continuities across development.
  
  • Assimilation: the process by which people translate incoming information into a form that fits concepts they already understand
  • Accomodation: the process by which people adapt current knowledge structures in response to new experiences
  • Equilibration: the process by which childen (or other people) balance assimilation and accomodation to create stable understanding
• Piaget’s theory divides cognitive development into four broad stages: the sensorimotor stage (birth to age 2), the preoperational stage (ages 2 to 7), the concrete operational stages (7 tot 12), and the formal operantional stage (age 12 and beyond). These stages reflect discontinuities in development.
•  In the sensorimotor stage, infants intelligence is expressed primarly through motor interactions with the environment. During this period, infants gain understanding of concepts such as object performance and become capable of deferred imitation.
  
  • Object performance: the knowledge that object continue to exist even when they are out of view
  • A-not-B-error: the tendency to reach for a hidden object where it was last found rather than in the new location where it was last hidden
  • Deferred imitation: the repetition  of other people’s behavior a substantial time afte rit originally occurred
• In the preoperational stage, children become able t orepresent their experiences in language, mental imagery, and symbolic thought; but because of cognitive limitations such as egocentrism and centration, they have difficulty solving many problems, including Piaget’s various test of conservation and egocentrism.
  
  • Symbolic representation: the use of one object to stnad for another
  • Egocentrims: the tendency to perceive the wold solely from one’s point of view
  • Centration: a tendency to focus on a single, peceptually striking feature of an object or event
  • Conservation concept: the idea that merely changing the appearance of objects does not necessarily change the object’s other key properties
• In the concrete operational stage, children become able to reason logically about concrete objects and events, but have difficulty reasoning in purely abstract terms and in succeeding on tasks requiring hypothetical thinking, such as the pendulum problem.
• In the formal operational stage, children become able tot hink systematically, test hypotheses in valid ways, and reason about hypothetical situations.
• Four weaknesses of Piagets’ theory are (1) it only vaguely descrbies the mechanisms that give rise to thinking and cognitive growth; (2) it underestimates infant’s and young children cognitive competence; (3) it understates the contribution of the social world to cognitive development; and (4) it depicts children’s thinking as being more consistent than it is. Each shortcoming has motivated a theory intended in large part to adress it.

Information-processing theories

• Information-processng theories focus on the specific mental processes that underlie chidlren’s thinking. Even in infancy, children are seen as actively pursuing goals; encountering physical, social, and processing limits; and devising strategies that allow them to surmount those limits and attain their goals.
  • Information processing theories: a class of theories that focus on the structure of the cognitive system and the mental acitivites used to deploy attention and memory to solve problems
  • Task analysis: the research technique of specifying th egoals, obstacles tot heir realization, and potential solution strategies involved in problem solving
  • Computer stimulation: a type of mathematical model that expresses ideas about mental processes in precise ways
  • Problem solving: the process of attaining a goal by using a strategy to overcome an obstacle
• The memory system includes working memory, long-term memory, and executive functioning.
• Working memory is a system for actively attending to, gathering, maintaining, briefly storing, and processing information.
• Long-term memory is the enduring knowledge accumulated over a lifetime.
• Executive functioning is crucial for inhibiting inadvisable actions, ehancing working memory, and flexibly adapting to changing situations. It develops greatly during the preschool and early elementary shcool years and it related to later academic achievement and occupational success.
• The development of memory, problem solving, and learning reflects improvements in basic processes, strategies and content knowledge.
  
  • Basic processes: the simplest and most frequently used mental activities
• Basic cognitive processes allow infants to learn and remember from birth onward. Among the most important basic processes are association, recognition, recall, generalizations, and encoding.
  
  • Encoding: the process of representing in memory information that draws attention or is considered important
• Acquisition of strategies and content knowledge enhances learning, memory, and problem solving beyond the level that basic processes alone could provide.
  
  • Rehearsal: the process of repeating information multiple times to aid memory of it
  • Selective attention: the process of intentionally focussing on the informatioin that is most relevant tot he current goal
• Important contributors tot he growth of problem solving include the development of planning and encoding.
• Overlapping waves theory characterizes development of problem solving as involving acquisiton of new strategies, increasingly efficient execution of existing strategies, and increasingly frequent choice of strategies that fit particular situations.

Core-knowledge theories

• Core knowledge theories are based on the view that children begin life with a wide range of specific cognitive competencies.
• Core-knowledge theories: approaches that view children as having some innate knowledge in domains of special evolutionary importance and domain-specific learning mechanisms for rapidly and effortlessly acquiring additional information in those domains
  
  • Domain specific: information about a particular content area
• Core-knowledge approaches also hypothesize that children are especially adept at acquiring evolutionary important information, such as language, spatial and numerical information, understanding of other people’s thinking, and face recognition.
• These approaches further posit that from early ages, children organize information about the most important areas into domain-specific knowledge structures.
• Nativism is a type of core-knowledge approach that posits that infants are born with substantial knowledge of evolutionary important domains.
• Core-knowledge constructivism proposes that children generate increasingly advanced theories of areas such as physics, psychology, and biology by combining basic innate knowledge with subsequent learning produced by both domain-general and domain-specific mechanisms.

Sociocultural theories

• Starting with Vygotsky, sociocultural theorists have focused on how the social world molds development. These theories emphasize that development is shaped not only by interactions with other people and the skills learned from them, but also by the artifacts with which children interact and the beliefs, values and traditions of the larger society.
• Sociocultural theories view humans as differening from other animals in their prospensity to teach and their ability to learn from teaching.
• Sociocultural theories describe people as learning through guided particpation and social scaffolding, in which others who are more knowledable support the learner’s efforts.
  
  • Guided participation: a process in which more knowledgable individuals organize activites in ways that allow less  knowledgeable people to learn
  • Social scaffolding: a process in which more competent people provide a temporary framework that supports children’s thinking at a higher level than children could manage on their own
  • Cultural tools: the innumerable products of human ingenuity that enhance thinking
  • Private speech: the second phase of Vygotsky’s internalization-of-thought process, in which children develop self-regulation and problem-solving abilities by telling themselves aloud what to do, much as their parents did in the first stage
• Establishing intersubjectivity between people through joint attention is essential to learning.
  
  • Intersubjectivity: the mutual understanding that people share during communication
  • Joint attention: a process in which social partners intentionally focus on a common referent in the external environment

Dynamic-systems theories

• Dynamic-systems theories view change as the one constant in development. Rather than depicting dvelopment as being organized into long periods of stability and brief periods of dramatic change, tehse theories propose that there is no period in which substantial change is not occurring.
  • Dynamic-systems theories: a class of theories that focus on how change occurs over time in complex systems
• These theories view each person as a unified system that, in order to meet goals, integrates perception, action, categorization, motivation, memory, language, and knowledge of the physical and social worlds.
• Dynamic-systems theories view development as a self-organizingn process that brings together components as needed to adapt to a contiuously changing environment, a process known as soft assembly.
• Just as variation and selection produce biological evolution, they also produce cognitive development.

Siegler Ch5 perception, action and learning in infancy (pp. 184-192)

Learning and memory

• Multiple forms of learning are present in infancy. Infants habituate to repeated stimuli, thereafter preferring novel stimuli. Through active exploration, they engage  in perceptual learning. They also learn through classical conditioning, which involves forming associations between natural and neutral stimuli, as well as through instrumental conditioning, which involves learning about the contingency between one’s own behavior and some outcome. They can track statistical patterns in their environments and make use of prior experiences to generate expectations about the future. Observational learning – watching and imitating the behavior of other people – is an important source of social information. By acting on the world, infants have the opportunity to make their own choices about what to learn.
  • Classical conditioning: a form of learning that consists of associating an initially neutral stimulus wiht a stimulus that always evokes a particular reflexive response
  • Unconditioned stimulus (UCS): a stimulus that evokes a reflexive response
  • Unconditioned response (UCR): a reflexive response that is elicited by the unconditioned stimulus
  • Conditioned stimulus (CS): the neutral stimulus that is repeatedly paired with the unconditioned stimulus
  • Conditioned response (CR): the originally reflexive response that comes tob e elicited by the conditioned stimulus
  • Instrumental (or operant) conditioning: learning the relation between one’s own behavior and the consequences that result from it
  • Positive reinforcement: a reward that reliably follows a behavior and increases the likelihood that the behavior will be repeated
  • Rational learning: the ability to use prior experiences to predict what will occur in the future
  • Active learning: learning by engaging with the world, rather than passively observing objects and events
• Infants’ memory abilities support learning even before birth and develop rapidly over the course of the first postnatal year.
   

Siegler Ch9 theories of social development (pp. 322-326)

Learning theories

• Watson believed strongly in the power of environmental factors, especially reinforcement, to influence children’s development.
• Skinner held that all behavior can be explained in terms of operant conditioning. He discovered the importance of intermittent reinforcement and the powerful reinforcing value of attention.
  
  • Intermittent reinforcement: inconsistent response to a behavior; for example, sometimes punishing unacceptable behaviors, and other times ignoring it
  • Behavior modification: a form of therapie based ono principles of operant conditioning in which reinforcemtn contingencies are changed to encourage more adaptive behavior
• Bandura’s social-learning theory and his empirical research stresses the importance of observational learning and cognition in social learning.
  
  • Reciprocal determinism: child-environment influences operate in both directions; children are both affected by and influence aspects of their environment

After exam A

Week 21

Siegler Ch4 (pp. 149-153)

Dynamic-systems theories

• Dynamic-systems theories view change as the one constant in development. Rather than depicting dvelopment as being organized into long periods of stability and brief periods of dramatic change, tehse theories propose that there is no period in which substantial change is not occurring.
  • Dynamic-systems theories: a class of theories that focus on how change occurs over time in complex systems
• These theories view each person as a unified system that, in order to meet goals, integrates perception, action, categorization, motivation, memory, language, and knowledge of the physical and social worlds.
• Dynamic-systems theories view development as a self-organizingn process that brings together components as needed to adapt to a contiuously changing environment, a process known as soft assembly.
• Just as variation and selection produce biological evolution, they also produce cognitive development.

Siegler Ch5 (pp. 176-184)

Motor development

• Motor development proceeds rapidly in infancy through a series of ‘motor milestones’, starting with newborn reflexes. Some aspects of motor development vary across cultures.
  • A particularly important aspect of motor development is the infant’s discovery of affordances – the possibilities for action offered, or afforded, by objects and situations.
• Each new motor achievement, from reaching to self-locomotion, expands the infant’s experience of the world but also presents new challenges. Infants adopt a variety of strategies to move around the world. In the process, they make some suprising mistakes.
  
  • Stepping reflex: a neonatal reflex in which an infant lifts first one leg and then the other in a coordinate pattern like walking
  • Pre-reaching movements: clumsy swiping movements by young infants toward objects they see
  • Self-locomotion: the ability to move oneself around in the environment
  • Scale error: the attempt by a young child to perform an action on a miniature object that is impossible duet o the large discrepancy in the relative sizes of the child and the object

Week 22

Siegler Ch6

Language development

• Acquiring a language involves learning the complex systems of phonology, semantics, syntax, and pragmatics, that govern its sounds, meaning, grammar, and use.
  • Generative: a system in which a finite set of word scan be combined to generate an infitnite number of sentences
  • Phonemes: the smallest units of meaningful sound
  • Morphemes; the smallest units of meaning in language
  • Syntax: rules specifying how words from different categories (nouns, verbs, adjectives, etc.) can be combined
  • Pragmatics: knowledge about how language is used
• Language ability is species-specific. The first prerequisite for its full-fledged development is a human brain. Nonhuman animals do not learn full-fledged human languages.
• The early years constistute a sensitive period for language acquisition; many aspects of language are more difficult to acquire thereafter.
• A second prerequisite for language development is exposure to language. Much of the language babies hear takes the form of infant-directed speech (IDS).
  
  • Infant-directed speech (IDS): the distinctive mode of speech used when speaking to infants and toddlers

The process of language acquisition

• Infants have remarkable speech-perception abilities. Like adults, they inhibit catecorigal perception of speech sounds, perceiving physically similar as belonging to discrete categories. As they learn  the sounds that are important in their language(s), infants ability to distinguish between non-native sound declines.
  • Prosody: the characteristic rhytm and intonational patterns with which a language is spoken
  • Catecorigal perception: the perception of phonemes as belonging to discrete categories
  • Voice onset time (VOT): the length of time between when air passes through the lips and when te vocal cords start vibrating
• Infants are remarkably sensitive tot he distributional properties of language and use them to segment words from fluent speech.
  
  • Word segmentation: discovering where words begin and end in fluent speech
  • Distributional properties of speech: in any language, certains sounds are more likely to occur together than are others
• Infants begin to babble at around 7 months of age, either repeating syllables (‘bababa’) or, if exposed to sign language, using repetitive hand movements.
  
  • Babbling: repetitive consonant-vowel sequences (‘bababa…’) or hand movements (for learnes in sign language)
• During the second half of the first year, infants learn how to communicate with other people, including developing the ability to establish joint attention.
• Infants begin to recognize highly familiar words at about 6 months of age, and they begin to produce words at about 1 year of age. Infants use a variety of strategies to figure out what new words mean.
  
  • Overextension: an overly broad interpretation of the meaning of a word
  • Underextenstion: an overly narrow interpretatioin of the meaning of a word
  • Pragmatic cues: aspects of the social context used for word learning
  • Cross-situational word learning: determining word meaning by tracking the correlations between labels and meanings across scenes and contexts
  • Synactic bootstrapping: the strategy of using grammatical structure to infer the meaning of a new word
• By the end of their second year, most toddles produce short sentences. The length and complexity of their utterances gradually increase.
  
  • Telegraphic speech: short utterances that leave out non-essential words
• In the early preschool years, children exhibit generlaizatioin, extending such paterns as ‘add -s to make plural’ to novel nouns, and making overregularization errors.
  
  • Overregularization: speech errors in which children treat irregular forms of words as if they were regular
• Children develop their burgeoning language skills as they go from collective monologues to sustained conversation.
  
  • Collective monologue: conversation between children that involves a series of non sequiturs
  • Narratives: story-like structured descriptions of past events

Theoretical issues in language development

• All current theories agree that there is an interaction between innate factors and experience.
• Nativists such as the influential linguist Noam Chomsky posit an innate knowledge of Universal Grammar, the set of highly abstract rules common to all languages.
  
  • Universal Grammar: a proposed set of highly abstract structures that are common to all languages
• Theorists focused on social interaction emphasize the communicative context of language development and use.
• Other perspectives argue that language learning requires powerful general-purpose cognitive mechanisms.
  
  • Connectionism: a computational modeling approach that emphasizes the simultaneous acitvity of numerous interconnected processing units

Nonlinguistic symbols and development

• Symbolic artifacts like maps or models require dual representation. To use them, children must represent both the object itself and its symbolic relation to what it stands for.
  • Dual representation: treating a symbolic artifact both has a real object and as a symbol for something other than itself
• Drawing and writing are popular symbolic activities. Young children’s early scribbling quickly gives way tot he intention to draw pictures of something. Early attempts at writing, while illegible, contain some characteristics of mature writing systems.

Siegler Ch8

• Alfred Binet and his colleague Théophile Simon developed the first widely used intelligence test. Its purpose was to identify children who were unlikely to benefit from standard instruction in the classroom. Modern intelligence are descendants of the Binet-Simon test.
• One of Binet’s key insights was that intelligence includes divers high-level capabilities that need tob e assessed in order to measure intelligence accurately.

What is intelligence?

• Intelligence can be viewed as a single trait, such as g; as few separate abilites, such as Thurstone’s primary mental abilities; or as a very large number of specific processes, such as those described in information-processing analyses.
  • G (general intelligence): cognitive processes that influence the ability tot hink and learn on all intellectual tasks
  • Fluid intelligence: ability to think on the spot to solve novel problems
  • Crystallized intelligence: factual knowledge about the world
  • Primary mental abilities: seven abilities proposed by Thurstone as crucial to intelligence (word fluency, verbal meaning, )
  • Three-stratum thoery of intelligence: Caroll’s model that places g at the top of the intelligence hierarchy, eight moderately general abilities in the middle, and many specific procesess at the bottom

Measuring intelligence

• Intelligence is often measured  through use of IQ tests, such as the Stanford-Binet and the WISC. These tests examine general information, vocabulary, arithemetic, language comprehension, spatial reasoning, and a variety of other intellectual abilities.
  • Wechsler Intelligence Scale for Children (WISC): widely use test designed to measure the intelligence of children 6 years and older
  • IQ (intelligence quotient): a quantative measure of a child’s intelligence relative tot hat of other children of the same age
    
    • Normal distribution: pattern of data in which scores fall symmetrically around a mean value, with most scores falling close tot he mean and fewer and fewer scores farther from it
    • Standard devation (SD): measure of the variability of scores in a distrubution; in a normal distribution, 68% of scores fall within 1 SD of the mean, and 95% of scores fall within 2 SD’s of the mean.
• A person’s overall score on an intelligence test, the IQ score, is a measure of general intelligence. It reflects the individual’s intellectual abiltiy relative to age peers.
• Most children’s IQ scores are quite stable over periods of years, though scores do vary somewhat over time.

IQ scores as predictors of important outcomes

• IQ scores correlate positively with long-term educational and occupational success.
• Other factors, such as social understanding, creativity, and motiviation also influence succes in life.

Genes, Environment, and the Development of Intelligence

• Development of intelligence is influence by the child’s own qualities, by the immediate environment, and by the broader societal context.
• Genetic inheritance is one important influence on IQ score. This influence tends to increase with age, in part duet o some gene snot expressing themselves until late childhood or adolescence, and in part duet o genes influencing children’s choices of environments.
• A child’s family environment, as measured by the HOME, is related tot he child’s IQ score. The relation reflects wihtin family influences, such as parents’ intellectual and emotional support fort he particular chid, as well as between-family influences, such as differences in partenal wealth and education.
• Schooling positivelly influences IQ score and school achievement.
• Broader societal factors, such as poverty and discrimination against racial and ethnic minorites, also influence children’s IQ scores.
• To alleviate the harmfull effects of poverty, the US had undertaken both small-scale preschool intervention programs as the much larger Project Head Start. Both have initial positieve effects on intelligence and school achievement, though the effects fade over time. On the other hand, the programs have enduring positieve effects on the likelihood of nog being held back in a grad and the likelihood of completing high school and enrolling in college.
• Intensive intervention programs, such as the Carolina Abecedarian Project, that begin in the child’s first year and provide optimal childcare circumstances and structured academic curricula have produced increases in intelligence that continue into adolescence and adulthood.

Alternative perspectives on intelligence

• Novel approaches to intelligence, such as Gardner’s multiple intelligences theory and Sternbergs theory of successful intelligence, attempt to broaden traditional conceptions of intelligence.
  • Theory of succesful intelligence: Sternberg’s theory of intellect, based on the view that intelligence is the ability to achieve succes in life

Acquisition of academic skills: reading, writing and mathematics

• Many children learn letter names and gain phonemic awareness before they start school. Both skill correlate with later reading achievement, and phonemic awareness is causally related to it.
  • Phonemic awareness: ability to identify component sounds within words
• Word identification is achieved by two main strategies: phonological recoding and visually based retrieval.
  
  • Phonological recoding skills: ability to translate letters into sounds and to blend sounds into words; informally called sounding out
  • Visually based retrieval: proceeding directly from the visual form of a word to its meaning
  • Strategy-choice process: procedure for selecting among alternative ways to solve a problem
• Reading comprehension benefits from authorization of word identification because it frees cognitive resources for understanding the tekst. Use of strategies, metacognitive understanding, and content knowledge also influence reading comprehension, as does the amount that children read themselves.
  
  • Simple view of reading: perspective that comprehension depends solely on decoding skill and comprehension of oral language
  • Dyslexia: inability to read and spell well despite having normal intelligence
  • Situation model: cognitive processes used t orepresent a situation or sequence of events
  • Comprehension monitoring: process of keeping track of one’s understanding of a verbal description or text
• Although many children begin to write during the preschool period, writing well remains difficult for many years. Much of the difficulty comes from the fact that writing well requires children to attend simultaneously to low-level processes, such as punctuation and spelling, and to high-level processes, such as anticipating what readers will and will not know.
  
  • Script: typical sequence of actions used to organize and interpret repeated events, such as eating at restaurents, going to doctor’s appointements, and writing reports
• As with reading, automatization of basic processes, use of strategies, metagcognitive understanding, and content knowledge influence development of writing.
• Most children use several strategies to learn arithmetic, such as adding by counting from 1, counting form the larger addend, and retrieving answers form memory. Children typically choose in adaptive ways, using more time-consuming and effortful strategies only on the more difficult problems where such approaches are needed to generate correct answers.
• Precise representations of numerical magnitudes facilitate learning arithmetic and other mathematical skills.
  
  • Numerical magnitude representations: mental models of the sizes of numbers, ordered along a less-to-more dimension
  • Mathematical equality: concept that the values on each side of the equal sign must be equivalent
  • Gesture-speech mismatches: phenomenon in which hand movevemtns and verbal statements convey different ideas
• As children encounter more advanced math, conceptual understanding becomes increasingly important. Understanding mathematical equality, for example, is essential for grasping advanced arithmetic and algebra problems.
• Mathematics anxiety can interfere with performance and learning because the heightened emotions reduce working-memory resources.

Week 23

Valkenburg & Piotrowski Ch4: Infants, toddlers and preschoolers

• Today, we understand that cognitive development and social-emotional development play independent and interdependent roles in predicting children’s media preference. Moreover, we know that the relationship between media use and child development is reciprocal.
• Some sensory preferences of children appear to be innate, whereas most others are shaped early in childhood.
• Children below the age of two spend nearly an hour a day viewing or using audiovisual media (television, DVDs, games, tablets).9 Interestingly, the age at which infants and toddlers start using media has fallen in the past decade; the current age is now estimated to be between three and five months. Developmentally, this age makes sense. By this age, vision has significantly improved, and children are thus able to follow moving objects on the screen. Moreover, around this age, the “social smile” emerges—the process of smiling when children hear or see something that they perceive as appealing. It is also around this age that infants begin to orient themselves toward situations that interest them, including media content
• When thinking of the developmental attributes of infants and toddlers, it is easy to see why this technology is so appealing. First, tablet screens are high contrast and are held closer than arm’s length, bringing them into the infants’ developing field of vision. Second, from a content perspective, the numerous “baby apps” available typically rely on colorful moving objects and characters and equally engaging sound effects—which appeal directly to children’s investigative-orienting system of attention. The tablet’s biggest plus, however, is that the software gives infants and young toddlers instant feedback. That is what fascinates them most, probably for the same reason that they enjoy switching lights on and off repeatedly or insist on playing with the remote control. Young children enjoy what they see as “magical” effects in their surroundings. Anything that changes because of an action on their part has their undivided attention
• This magical appeal of tablets for infants and toddlers can be explained by the moderate discrepancy hypothesis. A touch screen diverges only moderately from infants’ and toddlers’ motor and cognitive development, a phenomenon not experienced earlier in the history of digital media. It offers very young children everything they could possibly want: motion with interesting sounds, high-contrast images, new and constantly changing experiences, and instant feedback that fosters a sense of control.
• Symbolic thinking improves steadily in toddlers and preschoolers, but because their thinking is not yet bound by the laws of logic, everything is possible in their minds. That is why young children are so awed by certain fantasy characters, and that is why they are also more easily frightened by them.
• Between the ages of two and three, children develop more complex feelings, known as self-conscious emotions. These include shame, jealousy, pride, empathy, and guilt. Self-conscious emotions appear only after children develop a sense of self-awareness, which generally starts at around twenty-two months
• The moderate discrepancy hypothesis predicts that children will prefer media products that reflect their own experience as closely as possible. Media products that are successful with this target group therefore key into their social-emotional development. Toddlers and preschoolers identify closely with media characters and want to see those characters expressing emotions that they recognize in themselves. But the perceptual boundedness of this age group requires emotions to be portrayed visually and straightforwardly.
• Known as gender segregation, this process takes place across social environments and cultures. Groups of boys and girls have different standards of social interaction, and those standards have a significant influence on children’s socialization
  
  • Biological or biosocial explanations suggest that gender differences are rooted in genetic and hormonal differences between men and women and that society merely exaggerates those differences. Second, gender differences can be ascribed to differences in the way boys and girls are reared. The third factor in gender segregation is behavior compatibility. This happens at around eighteen months, when boys and girls start to diverge in their interests and preferences and find that members of the opposite sex often do not like what they like.
  • It seems, then, that children’s preferences for media content—including media characters—become more gender stereotyped as their own gender identity becomes more rigid. These differences between boys and girls fade away during elementary school, but return with a vengeance once puberty hits.

Valkenburg & Piotrowski Ch5 Children

• The period from five up to eight years of age is generally considered a transitional time. Piaget believed that children between these ages were still in the preoperational stage. And in fact, many of the characteristics exhibited by toddlers and preschoolers carry over into this period. Physical growth continues, but more slowly and with less spectacular spurts than before. Children in this period are still perceptually bounded in that they pay more attention to the external features of an object or person than to information that is less explicitly perceptible. By the time they are nine, however, this tendency has largely disappeared. The same is true of centration (that is, their tendency to focus on the visually salient features of a product or person and their inability to take in multiple details at once).
• Most children this age still have trouble distinguishing realistic from unrealistic media content, but as with their perceptual boundedness and centration skills, their ability to separate fantasy from reality improves
• Why are young elementary schoolchildren strongly attracted to fast-paced and action-packed entertainment? First, compared with their toddler and preschooler counterparts, children in this age group have dramatically CHILDREN 67 improved cognitive-processing abilities, and so the slow (often educational) content they once preferred becomes boring. Another explanation is that the action and (occasional) violence in such entertainment programs can function as rebellion against the restrictions that adults impose on children. A final explanation for the success of action-packed entertainment is that the events in this content often involve a group of peers or friends.
• But children in this age group—and many older children—greatly enjoy entertainment with characters that present the world in binary contrasts. They often will use such portrayals to help them interpret the world around them and to help inform their gender identity.
• Speaking of gender identity, children in this transitional period typically become acutely aware of their gender roles, developing very rigid ideas about what members of their sex can and cannot do
• Eight- to twelve-year-olds are capable of “decentering.” Whereas younger children tend to focus on the most striking aspects of an object or a piece of information (referred to as centration in chapter 4), these children use their newfound logical abilities to scrutinize, down to the last detail, every product that attracts their attention
• Children of this age become more critical not only of their parents, friends, and family, but also of commercials, games, and television programs that are not action packed or newsworthy. They are no longer as impressed by special effects and fantasy characters, and think that such features cannot compensate for a boring story. In addition, children at this age are able to divide their attention between many different activities, and nearly 30 percent of preadolescents use other media while watching television
• Children of this age are concrete-operational thinkers. Besides having an eye for the details of objects that they collect, they feel a pressing need to follow rules and to order and categorize their surroundings.
• Because most of their fantasy characters have been demystified, they come to identify primarily with real-world human idols, such as sports heroes and movie stars.
• As they get older, however, children increasingly depend on less visible information (that is, by focusing more on motives and contextual information) to help them interpret other people’s emotions. They also start to understand that people can have more than one emotion at once, and that they can hide their feelings or even feign them. Given these more advanced social-emotional skills, combined with their heightened interest in details and realism, it makes sense that preadolescents recognize and loathe bad acting
• Children’s growing capacity to see things from different perspectives influences not only how they deal with people in their real-life environment, but also their preferences for characters in media. While preschoolers tend to focus on physical similarities when it comes to character preference, preadolescents are more attentive to the psychological or social aspects of a character’s personality.
• As children’s social-emotional development increases in complexity, so does their interaction with peers.
• Preadolescent boys and girls differ in important ways when it comes to their entertainment preferences, but the differences are less stark than earlier in childhood
• CONCLUSION: We discussed that between five and eight years of age, interest in educational media is replaced by an interest in faster and more complex and action-packed content. Moreover, children in this age group exhibit highly gendered media preferences—reflecting the statement that “when it comes to toys, girls will be girls and boys will be boys.” Importantly, as children leave this transitional period, they enter preadolescence—a period characterized by a more sophisticated cognitive and social-emotional development. This enhanced developmental level leads to an interest in more complex and realistic content, and it can also make them more critical of poorly produced media content. They are interested in media characters that are psychologically similar to themselves, and in social situations with which they can identify and learn from. The media content and toys of their former years are no longer “cool,” and they quickly try to find their footing as soon-to-be adolescents. Yet despite all their “adult” preferences, preadolescents are still children in many respects. Although they are reluctant to admit it, approximately CHILDREN 77 a quarter of ten- and eleven-year-old girls still play with Barbies.25 They want autonomy, but have a distinct preference for operating in the safe environment of same-sex groups. And while most have a budding interest in sexuality, they are mainly taken up with belonging and having lots of friends. No longer children, and not yet teens, they are truly “tweens”— working to find their footing in a complex world.

Valkenburg & Piotrowski Ch6: Adolescents

• Gray matter, which consists of the cell bodies, dendrites, and axon terminals of neurons (nerve cells), is responsible for information processing. White matter, made up of the axons themselves, consists of the pathways that connect neurons to one another. The decline in gray matter, known as “pruning,” is said to indicate that the brain is beginning to function more efficiently. The “use it or lose it” principle applies here: neurons that are used will survive, and those that are not will disappear.4 Unlike gray matter, white matter increases in volume throughout late childhood ADOLESCENTS 81 and adolescence.5 This increase is mainly responsible for the faster and more efficient communication between the different regions of the preadolescent and adolescent brain, which helps explain a good deal of adolescents’ thinking and behavior.
• In other words, the maturity of their prefrontal cortex appears to depend on their motivation to keep their appointments, to structure their thoughts, and plan their activities.
• Story lines should be logical, characters should fit within the context of adolescents’ social and cultural background, and historical and situational factors should be true to life. Compared to their younger peers, early adolescents prefer increasingly complex content— including content that relies on more abstract ideas and problems—but this, too, should be plausible. They also begin to prefer characters that are more psychologically complex,
• Early adolescents become interested in complex forms of humor involving irony, sarcasm, and cynicism. This is a logical development, since more complex humor requires the ability to size up both a situation and the motives of those displaying that humor—in other words, the metacognition and social cognition that accompany adolescent development
• As children move into early adolescence, they show an increased interest in horror movies, vampires, and high-risk sports, for example, BMX biking and BASE jumping. Why might this occur? One primary explanation is again associated with their brain development. Recall that during this period, there is an increase in the activity of neural axons. These axons use dopamine, a neurotransmitter that sends signals between neurons and is commonly associated with the pleasure system of the brain. In particular, dopamine is thought to co-occur with feelings of enjoyment and to reinforce a tendency to do (or continue to do) certain ADOLESCENTS 85 activities. Dopamine also plays a role in the desire to embark on new or exciting adventures.
• The changes in the dopamine system during adolescence may lead teens to act more impulsively than children or adults and to show a greater tendency toward risk taking.
• Given this imbalance between their advanced cognitive functioning and their still-developing intuition, combined with their highly active dopamine system, it is not surprising that risk-taking behaviors increase dramatically in frequency during the adolescent years—reaching an all-time high toward the end of puberty.
• While cognitive development is a core aspect of the adolescent years, teens’ social-emotional development is just as significant. One of the crucial goals of adolescence is the development of autonomy—defined as the capacity to make independent decisions and care for oneself. To gain autonomy, teens have to develop three key social-emotional subgoals. First, they need to develop a stable identity, a reasonably firm sense of who they are and who they would like to become. Second, they must develop a sense of intimacy, which refers to close relationships in which partners are open, caring, and trusting.17 In adolescence, teens must acquire the skills needed to form such close relationships. Finally, they need to discover their sexual identity.
• Two things are important for adolescents trying to develop a stable self-concept and self-esteem: the approval of their social environment and the possibility of influencing that environment. Social media offers teens both.
• Late adolescence (sixteen to nineteen years old) is the period that follows puberty. The physical changes continue, but they are less noticeable, and their impact on self-concept and self-esteem is milder than during early adolescence. While early and late adolescents share many preferences, they also differ in several important ways. One important cognitive change in late adolescence is the rapid improvement of so-called executive functions, which refer to the cognitive functions needed for effective, efficient, socially adapted behavior.
• Late adolescents also have little trouble putting their ideas into words. Furthermore, along with advancements in executive function, late adolescents develop intuition—something many experts consider necessary for making good decisions. As a result, they are less inclined than their younger counterparts to pursue immediate, dopamine-fueled rewards, and are more likely to start thinking about the future and possible careers.36 Indeed, starting around sixteen years of age, adolescents’ preference for risk taking begins to decline
• Among late adolescents, media preferences are in a transitional state. While they still share many of the same preferences of early adolescents, they also share many of the preferences of young adults. For example, they continue to feel attracted to fast-paced media and still show some interest in television and music targeting teenagers (although this starts to fade). But their understanding of humor is more advanced and mimics that of adults. No longer are their cognitive development and social-emotional development the main predictors of their appreciation of humor; other factors, such as educational level and cultural background, come to play an important role
  
  • Therefore, the best way to reach late adolescents is to address them as the mature people that they are soon becoming
• While peers remain crucial during late adolescence, the relationship between teens and their parents often improves during this time
• Late adolescents still feel a tremendous need to communicate with peers. By this period, many friendships have developed into full-fledged, intimate, and caring relationships that resemble those between adults.
• By the end of adolescence, teenagers are somewhat less under the sway of cliques and crowds—although there are significant individual differences in this regard. Instead, late adolescents tend to be more focused on communicating with individuals than with their group. Moreover, romantic relationships—and the influence of these relationships on behaviors—begin to take precedence
• During early adolescence, teens move toward autonomy by working to discover their identity, developing intimacy, and beginning to understand their sexuality. This process continues among late adolescents, who are still working on stabilizing their identity and self-esteem. In doing so, they still experience a strong need for introspection, that is, a need to examine their own experiences and emotions.
• One of the largest differences between early and late adolescence is associated with sexuality. Whereas early adolescents are beginning to discover their sexuality and perhaps may have their first “puppy love,” it is during late adolescence that most teenagers have their first sexual experience with another person

CONCLUSION: We highlighted how the significant changes in brain development, particularly during early adolescence, lead to an increased interest in content that is fast and complex, ADOLESCENTS 95 relies on complex humor, and features riskier content such as extreme sports. Moreover, we highlighted how adolescents are charged with tackling three social-emotional tasks: developing an identity, learning about intimacy, and discovering their sexuality. As we have shown, these three developmental tasks have major consequences for behavior and preferences in early and late adolescence. For example, they are the reason early adolescents want to communicate constantly with peers, feel a need to belong, and seek information and validation for aspects of their identity from peers or from idols or heroes in the media. This triple social-emotional developmental challenge also explains why early adolescents spend so much time on social media and with entertainment media. Social media offer young teens ample opportunity to communicate endlessly with peers. In addition, more than ever before, social media provide early adolescents with the opportunity to discover and validate their identity, including their sexual identity. Entertainment media also help them in this respect. Media heroes and idols have long taught adolescents how to behave and how to deal with problematic social situations such as relationships, bullying, and falling in love. Late adolescents have some of the same preferences as early adolescents, such as a liking for fast-paced entertainment programs, but in other respects they begin to look much more like young adults. Their sense of autonomy and self-control increases considerably, and their media preferences are more mature. They are less concerned with accumulating as many friends as possible, but instead start to focus on the quality of their friendships and romantic relationships. It is a period typically marked by one’s first sexual relationship, and it is thus a crucial time for stabilizing one’s identity and establishing oneself as an autonomous person. This autonomy means that efforts to reach this audience through traditional “teenage approaches” are often unsuccessful. Instead, in this somewhat transitional period, it becomes increasingly important that media producers treat this audience as the autonomous individuals they are striving to become.