Developmental Psychology

Prepared by J. W. Taylor V

Developmental Psychology 

The scientific study of biological, cognitive, social, and personality development throughout the life span

Seven Stages of Development Prenatal

Conception to Birth

Infancy

Birth to 2 years

Childhood

2 to 12 years

Adolescence

12 to 18 years

Young Adulthood

18 to 40 years

Middle Adulthood

40 to 65 years

Late Adulthood

65 years and over

Prenatal Development 

Human conception begins when a sperm penetrates the membrane of an ovum 

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When the two combine, a complete set of genetic instructions is formed, half from the father and half from the mother

The fertilized egg that is formed from the union of the sperm and egg is called a zygote

The Gene 

The basic unit of genetic instructions 

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Genes are short segments of chromosomes, molecules of DNA that hold the genetic instructions for every cell in our body

Every cell of a normal human has 23 pairs of chromosomes, one of each pair coming from the mother and one from the father

Sex Determination 

It is the 23rd pair of chromosomes that determines a person’s sex   

In a female, there are two X-shaped chromosomes (XX) In a male, there is one X-shaped chromosome and one smaller Y-shaped chromosome (XY) It is the Y chromosome that leads to the development of a male, so the sex of the zygote is determined by which sperm X or Y, fertilizes the egg

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A major issue in developmental psychology is the nature-versus-nurture question

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A major issue in developmental psychology is the nature-versus-nurture question

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A major issue in developmental psychology is the nature-versus-nurture question

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Twins 

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Sometimes the growing cluster of duplicated cells breaks apart early in development resulting in two clusters with identical genes These clusters become identical (monozygotic) twins because they come from the same zygote

Twins 

Fraternal (dizygotic) twins originate from the fertilization of two eggs at about the same time 

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Chance determines which of the 23 pairs of chromosomes goes to a reproductive cell, so there are about 8 million chromosome possibilities for each reproductive cell in each parent Consequently, fraternal twins, as well as any two children of the same parents, may vary greatly in appearance

Stages of Prenatal Development Germinal

Begins with the formation of the zygote and ends after about 2 weeks, when the outer portion of the zygote’s developing cluster of cells has attached itself to the uterine wall

Embryonic

From 2 weeks to about 2 months, the major structures and organs of the body begin to develop, and the embryo starts to resemble a human being

Fetal

From about 2 months to birth, the developing organism is called a fetus, and through very rapid growth, the body structures and organs complete their growth

Influences 

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Prenatal development is mainly a function of the zygote’s genetic code (nature), but the environment (nurture) also plays a role Teratogens are environmental agents (such as drugs or viruses), diseases (such as German measles), and physical conditions (such as malnutrition) that impair prenatal development and lead to birth defects or even death

How We Develop During Infancy

Motor Development

SensoryPerceptual Development

Motor Development 

A reflex is an unlearned response to a specific stimulus 

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The Babinski reflex occurs when an infant fans her toes upward when her feet are touched The grasping reflex occurs when an infant grasps any object that touches their palms The sucking reflex leads an infant to suck anything that touches its lips The rooting reflex leads an infant to turn its mouth toward anything that touches its cheeks and search for something to suck

Sensory-Perceptual Development 

Preferential-looking technique is used to study vision 

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Two visual stimuli are displayed side by side, and the researcher records how long the infant looks at each stimulus If the infant looks at one stimulus longer, it is inferred he can tell the difference between the two stimuli and has a preference

Sensory-Perceptual Development 

Preferential-looking technique is used to study vision

Sensory-Perceptual Development 

Habituation is a decrease in the physiological responding to a stimulus once it becomes familiar 

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Infants, for example, tend to look longer at novel stimuli If infants look longer at a new stimulus than an old one, then it is inferred he must be able to perceive the difference between the two stimuli Infants also intensity their sucking of a pacifier in their mouths when confronted with a novel stimulus

Sensory-Perceptual Development 

Vision is the least-developed sense at birth   

Newborns’ visual acuity is estimated to be about 20/400 to 20/800 Visual acuity reaches 20/20 within the first year of life Color vision develops by 2 to 3 months

Sensory-Perceptual Development 

Hearing in the newborn is more fully developed than vision 

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Can distinguish their mother’s voice from those of others This ability appears to develop in the womb before birth By 6 months, an infant’s hearing is comparable to that of an adult

Sensory-Perceptual Development 

The senses of smell, taste, and touch are also fairly well-developed at birth 

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Infants can differentiate the smell of their mother from those of other people

Very young infants may have an innate conceptual understanding of object movement (e.g., that objects cannot go through solid surfaces)

How We Learn Language 

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No other animal seems to be able to acquire and develop language ability as humans do Children in different cultures learn to speak very different languages, but they all seem to go through the same sequence of stages

Language Stages 

Infants communicate through crying, with different cries for hunger and for pain, and through movement and facial expressions 

Prefer baby talk (or motherese) – the different format of speech that adults use when talking with babies that involves the use of shorter sentences with a higher, more melodious pitch than normal speech Video

Kellogg’s Chimpanzee Study 

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A husband and his wife adopted a 7-month old chimpanzee and raised it along with their own infant. Initially the chimp progressed more quickly than their human infant. By 2 years though the human infant had passed the chimp in all aspects of development except strength and hair.

Maturation 

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The automatic, orderly, and sequential process of physical and mental development. Video

Maturation 

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The automatic, orderly, and sequential process of physical and mental development. Video Without a stimulating environment a child's development can be slowed or delayed. However, no toy or activity can speed a child's development beyond their internal pace.

Critical Periods 

A critical period is a special time period in an animal’s maturation when a particular skill may be learned.

Critical Periods 

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A critical period is a special time period in an animal’s maturation when a particular skill may be learned. An example is “imprinting” that is possible with ducklings. Video

Critical Periods 

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A critical period is a special time period in an animal’s maturation when a particular skill may be learned. An example is “imprinting” that is possible with ducklings. Video In humans, learning a foreign language before the age of 12 years old will result in a correct accent. After 12 you will have an accent.

“Attachment” 

How important is maternal support in the development of a healthy infant?

“Attachment” 

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How important is maternal support in the development of a healthy infant? Researchers use the term attachment in place of the term “love”

“Attachment” 

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How important is maternal support in the development of a healthy infant? Researchers use the term attachment in place of the term “love” Harlow’s monkey experiments - video

Parenting Styles

Parenting Styles 

Permissive Parenting – where parents let children do as they wish and few rules are made or enforced. Children raised this way are often impulsive, irresponsible and lack self-discipline. They may not get along well with other children.

Parenting Styles 

Authoritarian (dictatorial) Parenting – where parents are rigid and inflexible. They set the rules and demand obedience, often administering harsh punishments when this does not occur. Children have very little input in decisions made about their life, which can lead to the children being moody and with poor self-esteem.

Parenting Styles 

Authoritative Parenting – where parents seek input from children. The parents do make rules and enforce them. However, they are both caring and flexible. Unlike authoritarian parents, they don’t simple hand down a solution that must be accepted by the child. Instead, authoritative parents listen and offer suggestions and support.

Parenting Styles 

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Childhood: “the good old days”

Childhood: “the good old days” 

Not very long ago (several hundred years ago) children were seen as “little adults”

Childhood: “the good old days” 

Not very long ago (several hundred years ago) children were seen as “little adults”

Childhood: “the good old days” 

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Not very long ago (several hundred years ago) children were seen as “little adults” This could have some unpleasant results

Childhood: “the good old days” 

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Not very long ago (several hundred years ago) children were seen as “little adults” This could have some unpleasant results

Childhood: “the good old days” 

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Not very long ago (several hundred years ago) children were seen as “little adults” This could have some unpleasant results

Childhood: “the good old days” 

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Not very long ago (several hundred years ago) children were seen as “little adults” This could have some unpleasant results Opinions about children and their unique development finally began to change only about 150 years ago.

Childhood: “the good old days” 

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Not very long ago (several hundred years ago) children were seen as “little adults” This could have some unpleasant results Opinions about children and their unique development finally began to change only about 150 years ago.

Jean Piaget 

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A Swiss psychologist that introduced theories of cognitive development in children. The theories have been around for a while but they are still used in education and child psychology.

Piaget’s Theory of Cognitive Development 

Piaget did not conduct formal experiments, but rather loosely structured interviews in which he posed problems for children to solve, observed their actions carefully, and questioned them about their solutions 

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Was particularly interested in children’s error, which would provide insights into children’s thought processes Assumed that a child is an active seeker of knowledge and gains an understanding of the world by operating on it

Schemas 

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Organized units of knowledge about objects, events, and actions Cognitive adaptation involves two processes 

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Assimilation is the interpretation of new experiences in terms of present schemes Accommodation is the modification of present schemes to fit with new experiences

Schemas 

For example, a child may call all fourlegged creatures “doggie” 

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The child learns he needs to accommodate (i.e., change) his schemes, as only one type of four-legged creature is “dog” It is through accommodation that the number and complexity of a child’s schemes increase and learning occurs

Piaget’s Stages of Cognitive Development Sensorimotor

Birth to 2 years

Preoperational

2 to 6 years

Concrete operational 6 to 12 years Formal operational

12+ years

Piaget’s Stages of Cognitive Development

Sensorimotor Stage 

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Infant learns about the world through their sensory and motor interactions (including reflexes) Lack object permanence, the knowledge than an object exists independent of perceptual contact Symbolic representation of objects and events starts to develop during the latter part of the sensorimotor stage (e.g., use of telegraphic speech)

Preoperational Stage 

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The child’s thinking becomes more symbolic and language-based, but remains egocentric and lacks the mental operations that allow logical thinking Egocentrism is the inability to distinguish one’s own perceptions, thoughts, and feelings from those of others 

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Cannot perceive the world from another person’s perspective

The child, however, can pretend, imagine, and engage in make-believe play

Preoperational Stage 

Conservation is the knowledge that the quantitative properties of an object (such as mass, volume, and number) remain the same despite changes in appearance 

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Some grasp of conservation marks the end of the preoperational stage and the beginning of the concrete-operational stage The liquid/beakers problem is a common test of conservation ability

Preoperational Stage 

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A major reason why a preoperational child does not understand conservation is that the child lacks an understanding of reversibility, the knowledge that reversing a transformation brings about the conditions that existed before the transformation Child’s thinking also reflects centration, the tendency to focus on only one aspect of a problem at a time

Tests of Conservation

Concrete Operational Stage 

Children gain a fuller understanding of conservation and other mental operations that allow them to think logically, but only about concrete events 

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Conservation for liquids, numbers, and matter acquired early, but conservation of length acquired later in the stage Develops transitivity (e.g., if A > B, and B > C, then A > C) Develops seriation, the ability to order stimuli along a quantitative dimension (e.g., a set of pencils by their length)

The reasoning of concrete operational children is tied to immediate reality (i.e., what is in front of them and tangible) and not with the hypothetical world of possibility

Formal Operational Stage 

The child gains the capacity for hypothetical-deductive thought 

Can engage in hypothetical thought and in systematic deduction and testing of hypotheses

Formal Operational Stage 

In one scientific thinking task, the child is shown several flasks of what appear to be the same clear liquid and is told one combination of two of these liquids would produce a clear liquid 

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The task is to determine which combination would produce the blue liquid The concrete operational child just starts mixing different clear liquids together haphazardly The formal operational child develops a systematic plan for deducing what the correct combination must be by determining all of the possible combinations and then systematically testing each one

Piaget’s Stages of Cognitive Development Video

Evaluation of Piaget’s Theory 

Recent research has shown that rudiments of many of Piaget’s key concepts (e.g., object permanence) may begin to appear at earlier stages than Piaget proposed 

For example, research that involved tracking infants’ eye movements has found that infants as young as 3 months continue to stare at the place where the object disappeared from sight, indicating some degree of object permanence

Evaluation of Piaget’s Theory 1. Not all people reach formal operational thought 2. The theory may be biased in favor of Western culture 3. There is no real theory of what occurs after the onset of adolescence 4. Despite refinements, recent research has indeed shown that cognitive development seems to proceed in the general sequence of stages that Piaget proposed

Attachment and Parenting Styles

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Attachment is the lifelong emotional bond that exists between the infants and their mothers or other caregivers, formed during the first six months of life Video

Attachment and Harlow’s Monkeys 

Harry Harlow separated infant monkeys from their mothers at birth and put them in cages containing two inanimate surrogate mothers, one made of wire and one made of terry cloth

Attachment and Harlow’s Monkeys 

Half of the monkeys received their nourishment from a milk dispenser in the wire and half from a dispenser in the terry cloth mother 

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All of the monkeys preferred the cloth monkey regardless of which monkey provided their nourishment The monkeys being fed by the wire mother would only go to the wire mother to eat and then return to the cloth mother Thus, “contact comfort,” not reinforcement from nourishment, was the crucial element for attachment formation

Attachment and Harlow’s Monkeys

Attachment and Harlow’s Monkeys 

When confronted with a strange situation (e.g., an unfamiliar room with toys) without the surrogate mother, the infant monkey would be fearful 

When the surrogate mother was brought into the strange situation, the infant monkey would initially cling to the terry cloth mother to reduce its fear, but then begin to explore the new environment and eventually play with toys

Parenting Styles Authoritarian Parents are demanding, expect unquestioned obedience, are not responsive to their children’s desires, and communicate poorly with their children Authoritative Parents are demanding but set rational limits for their children and communicate well with their children Permissive

Parents make few demands and are overly responsive to their child’s desires, letting their children do pretty much as they please

Uninvolved

Parents minimize both the time they spend with the children and their emotional involvement with them, doing little more than providing for basic needs

Parenting Styles 

An authoritative parenting style seems to have the most positive effect on cognitive and social development 

Children are the most independent, happy, self-reliant, and academically successful of the four parenting styles

The End