DPL 1

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Chapter 1: Introduction

Chapter 1: Definitions

Development: systematic continuities and changes that people display over a course of their lives that reflects the influence of biological maturation and learning

Developmentalists: studies the process of development

(goal of developmentalists are to describe, explain and optimize development)

Normative developments: typical developments that characterizes all members of a species

Ideographic developments: developments that vary amongst individuals

Human development: continuous and cumulative process that is holistic, highly plastic, and heavily influenced by historical and cultural contexts in which it occurs

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Chapter 2: prenatal development and birth

period of zygote: first phase of prenantal development, which lasts from conception to implantation

-lasts about 2 weeks, from conception to implantation

-After fertilisation, zygote moves down fallopian tube towards uterus and divides into 2 cells by mitosis

-the 2 cells will continue to divide until a ball-like structure (blastocyst) is formed {blastocyst about 60-80 cells within 4 days of conception}

-inner layer of blastocyst-embryo; outer layer of blastocyst-develop into tissues to protect and nourish the embryo

-blastocyst approaches uterus after 6-10 days of conception

-implantation (burrowing of blastocyst into lining of uterus) occurs once blastocyst reaches uterus

period of embryo: second phase of prenatal development, which lasts from the 3rd to 8th prenantal week, where the major organs and anatomical structures take shape

-embryonic disk differentiates into 3 layers: ectoderm, mesoderm, endoderm

-ectoderm(outer layer) will become nervous system, hair and skin

-mesoderm(middle layer) will become muscles, bones and circulatory system

-endoderm(inner layer) will become the digestive system, lungs, urinary tract, and other vital organs

-after 3rd week, portion of ectoderm develops into the neural tube (develops into spinal cord and brain)

-by 4th week, heart formed and beating. eyes,nose,ears and mouth slowly forming. Buds of arms and legs also appear.

-by 5th week, eys have corneas and lenses

-by 7th week, ears well formed, embryo has rudimentary skeleton, limbs developing(arms then legs)

-during 7th-8th week, embryo's sexual orientation develops with appearance of indifferent gonad.

-if male, gene on Y chromosome triggers indifferent gonad to produce testes.

-if female, indifferent gonad receives no instructions and will produce ovaries.

-during 7th to 8th week, circulatory system functions on its own

-by 2nd month, major structures of human formed, more recognizable as human

period of fetus: lasts from 9th week of pregnancy till birth, where rapid growth and refinement of all organ systems occurs

-9th to 12th week: rapid growth and interconnection between all organ systems allowing new competencies like swallowing, digestion of nutrition and urination

-13th to 24th week: fetus grows rapidly. fetus movement can be felt by mother and fetal heartbeat can be heard. Fetus is covered by vernix (white,cheesy substance) to prevent chapping. fetus has lanugo (fine layer of body hair) to help vernix stick to skin.

-25th to 38th week: growth continues, organ system mature in preparation for birth. Reaches age of viability (a point between 22nd and 28th prenatal week when survival outside uterus is possible). Layer of fat develops under skin. Activity is less frequent, and sleep is more frequent.

POTENTIAL PROBLEMS IN PRENATAL DEVELOPMENT:

Teratogens: external agents, such as viruses, drugs and chemicals that can harm a developing embryo or fetus.

-can cause physical deformities, severely retarded growth, blindness, brain damage, or even death

-worst during period where structure is forming and growing most rapidly (week 3 to week 8) (sensitive-period principle)

- Sensitive period:period in which organism is most susceptible to environmental influences {gross physical defects: 3-5 week; heart:3-6 week}

-same defect can be caused by different teratogens

-variety of defects can result from a single teratogen

-longer the exposure to teratogen, the more likely serious harm will be done (dosage principle)

-some teratogens may cause "sleeper effects" that may not be apparent until later in the child's life (sleeper-effect principle)

Diseases suffered by pregnant women

1. Rubella: German measles; little effect on pregnant women, but may cause serious birth defects in developing organisms if exposed in first 3 to 4 months of pregnancy

2. Toxoplasmosis: disease caused by parasite found in raw meat and cat feces. Can cause birth defects if transmitted to embryo in first trimester, and may result in miscarriage if later in pregnancy.

3. Sexually transmitted diseases (Eg. syphilis, genital herpes, AIDS)

syphilis: can cross placenta barrier in the middle and later stages of pregnancy, causing miscarriage or severe birth defects

Genital herpes: can infect infants during birth, causing blindness, brain damage, and even death. women w herpes are advised for cesarean delivery to prevent infection. (delivery of baby through incision in pregnant woman's abdomen and uterus)

AIDS (Acquired immunodeficiency syndrome): transmitted by mother or neonate that results in weakening of body's immune system, and eventually death. {incurable}

4. Drugs(eg. thalidomide, drugs containing diethylstilbestrol (DES), alcohol: may result in fetal alcohol syndrome/fetal alcohol effects (FAS/FAE), cigerette smoking, illict drugs)

Fas: serious congenital problems observed in offsprings of mothers who abuse alcohol during pregnancy. May result in babies displaying excessive irritability, hyperactivity, seizures. They will also be smaller & lighter than normal, physical growth lags behind

Fae: mild congenital problems observed in offsprings of mothers who drink sparingly and moderately during pregnancy. May result in retarded physical growth and minor physical abnormalities (eg. poor motor skills, difficulty paying attention...)

5. Environmental hazards (eg. radiation, chemicals and pollution)

Birth and the perinatal environment:

childbirth is a 3 step process:

1. contractions that dilate the cervix (1st stage of labour)

2. baby delivery (2nd stage of labour)

3. afterbirth (last stage of labour)

Apgar test is used to access the newborn's conditions immediately after birth

Neonatal behavioural assessment scale (NBAS) is a more extensive measure of the baby's health and well-being, which is administrated a few days later.

Potential problems at birth:

Anoxia: lack of oxygen to brain, may lead to neurological damage or death

Preterm babies & small-for-date-babies: usually occur when mothers abuse alcohol and drugs

small for date babies have more sever and long lasting problems

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Chapter 3: Infancy

Newborn Reflexes: automatic response to a stimulus

Survival reflexes (permanent)

examples:

breathing reflex: provide oxygen, expel carbon dioxide {action: inhale & exhale}

eye-blink reflex: protects eyes from foreign objects or bright light {action: closing/blinking eyes}

pupillary reflex:protects again bright lights & adapts the visual system to low illumination {action: constriction of pupils due to bright light/ dilation to dimly lit surroundings}

rooting reflex: orients baby to breast/bottle {action: turning the head to the direction of touch} *disappears over first few weeks of life and will be replaced by voluntary head turning*

sucking reflex: allows baby to take in nutrients {action: sucking on objects that are placed into mouth

swallowing reflex: allows baby to take in nutrients {action: swallowing}

Primitive reflexes (will disappear)

babinski reflex: disappears within first 8 months to 1 year of life {action: curling and fanning of toes when bottom of feet is stroked}

Palmar grasping reflex: disappears in first 3-4 months and is replaced by voluntary grasp {action: curling of fingers around objects that touch the babies palm}

Moro reflex: disappears within first 4-6 months {action: loud noise/ sudden change of position of the baby's head will cause the baby to throw his/her arms outward/ arch his back and then bring his arms towards each other}

Swimming reflex: disappears within first 4-6 months {action: when infant is immersed in water, they will involuntarily move their legs and arms, and hold their breath}

stepping reflex: disappears in first 8 months {action: when infants are held upright and their feet touch a flat surface, they will step as if to walk)

VISUAL PERCEPTION

0-2 months: early pattern perception

-prefer to look at a more complex stimuli

-can only see a black glob when shown highly complex checkerboard, probably because their immature eyes don't accommodate well enough to resolve the fine detail

2 months-1 year: later form perception

-sees better, and is capable of making more complex visual discrimination

PERCEPTION OF THREE-DIMENSIONAL SPACE

Size constancy

-tendency to perceive an object as the same size from different distances despite changes in size of its retinal image

Use of pictorial cues

Development of depth perception

-visual cliff

intermodal perception: ability to recognize by one sensory modality an object/experience that is already familiar through another modality

example: when child is told to feel a golf ball without seeing it, he would be able to identify it as a golf ball due to its shape, despite not having touched one before.

Basic learning processes in infancy:

Learning: relatively permanent change in behaviour that results from one's experience

Habituation

-process in which infants come to recognise and cease responding to stimuli that are presented repeatedly

-simplest form of learning

-may be possible even before birth (eg. when vibrator placed on mother's abdomen, they may be quite active initially, but they will eventually stop moving as these vibration sensations are familiar to them)

- improves dramatically over first few months of life

-infants have different rate at which they habituate

Classical conditioning

-a type of learning in which a neutral stimulus(conditioned stimulus) that initially has no effect on the infant eventually elicits a response(conditioned response) of some sort by virtue of its association with a second stimulus(unconditioned stimulus) that always elicits the response.

example: initially, when a child is shown a cat, he does not appear to fear this stimuli. However, what caused him to be startled and be afraid, would be when a hammer struck a metal rod behind him. This caused him to burst into tears. After it was done repeatedly over a period, the child would burst into tears whenever he saw the cat, even when the metal rod was not struck.

Operant conditioning

-organism learns to engage in a behaviour that is reinforced.

the process: child emits a response -> which produces a response -> which affects the likelihood that the action will be repeated.

for example: when a child draws on the wall, he receives a scolding from his mother, and this results him in stopping the action of drawing on the wall

Observational learning

-learning that results from observing the behaviour of others.

-occurs when the observer attends to the model and constructs symbolic representation of its behaviour. The symbolic codes are stored in memory and may be retrieved at a later date to guide the child's attempts to imitate the actions she has witnessed.

-infants get better at imitating social models and by the end of their 1st year, they may display deferred imitation (ability to produce a modeled activity that was witnessed in the past)

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Chapter 5: Physical development

Overview of maturation and growth:

growth patterns:

height and weight:

first 2 years:

-Doubling birth weight by 4-6 months of age

-tripling birth weight by end of 1st year

age 2 till puberty:

-grows 2-3 inches in height and 6-7 pounds in weight each year

ages 6-11 (middle childhood):

-children seem to grow very little for the entire year

-as little as 2 inches in height and 6 pounds in weight

adolescents

-enter 2-3 year growth spurt

-annual growth of 10-15 pounds and 2-4 inches in height

Changes in body proportions:

CEPHALOCAUDAL development:

-progressive development of skills and abilities, which starts from our head and ends at our feet, going through the trunk in a vertical and descendent direction.

-trunk grows fastest in first year

PROXIMODISTAL development:

-progressive development of the skills and abilities, starting from the centre of the body, towards the members, going through the shoulders, elbow, wrist and ending with the fingers.

-during prenatal development, chest and internal organs develop first, followed by arms & legs, then hands and feet.

**REVERSES DURING PUBERTY; HAND & FEET ATTAIN ADULT PROPORTION FIRST, THEN ARMS & LEGS, THEN TRUNK*

Skeletal development:

-initially are soft cartilage, but will gradually ossify into bony material

-skull bones are separated by 6 soft spots that will gradually be filled in by minerals to form a single skull by 2 years

>infant's bones are soft, pliable and difficult to break

~therefore, newborns are unable to sit down/ balance (bones are too flexible)

>neonate skull consists of soft bones that can be compressed to allow child to pass through the cervix and birth canal; making childbirth easier for mother & baby

-skeletal bones harden at different rates:

skulls and hands mature first

leg bones grow continuously until mid to late teens

skeleton development is completed by 18

Muscular development:

-proceeds in cephalocaudal and proximodistal direction

-at birth, muscle tissue contains 35% water

-muscle tissues grow as water is bolstered by protein and salts

-gradual growth is present during childhood, spurts over adolescence

Variation in physical development:

>different bodily systems display unique growth patterns

Individual variations

Cultural variations

Development of the brain:>last 3 prenatal months & first 2 years aft birth (period of brain growth spurt)

Motor development:

LOCOMOTIVE DEVELOPMENT:

-changes of children's mastery of mobility

maturational viewpoint:

-unfolding of a genetically programmed sequence of events in which the nerves and muscles mature in a downward and outward direction

-universal sequence of motor milestones

-practice had little effect on motor development

Experiental hypothesis:

-importance of developing motor skills stem from providing opportunities to practice and use them

-experiences through practice influence the maturation of capabilities

(eg. grasping the child's armpits, while propelling them forward

Dynamic and goal-directed:

-each new motor skill is constructed as children actively identify their motor abilities and develop these skills into more complex systems

-use of more effective ways of achieving objectives or interacting with the environment

FINE MOTOR DEVELOPMENT: body movements associated with grasping,holding and manipulating objects

VOLUNTARY REACHING

-Process of how infant learn to reach for objects to discover their world.

-hit and miss experience

DEVELOPMENT OF MANIPULATIVE SKILLS

-Transferring objects from hand to hand

-eg. scribbling and drawing

*ULNAR GRASP->PINCER GRASP*

4 stages in children's drawings:

1. placement

2.shape

3.design

4.pictorial stages

Environmental influences on physical development:

NUTRITION

-undernutrition:

consequence: brain growth may be severely retarded, child may remain relatively small in stature

Maramus: insufficient protein and too few calories

Kwashiorkor: enough calories but insufficient protein

vitamin and mineral deficiency

iron deficiency anemia

ILLNESSES

-major illnesses: pneumonia, diarrhea, malaria, measles, malnutrition

EMOTIONAL STRESS AND LACK OF AFFECTIONS(growth to slow dramatically or stop)

-nonorganic failure to thrive

-deprivation dwafism

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EMOTIONAL DEVELOPMENT, TEMPERAMENT, AND ATTACHMENT

Basic emotions: set of emotions present at birth

Complex emotions: self-conscious or self-evaluative emotions that emerge in the 2nd year

emotional display rules: culturally defined rules specifying which emotions should or should not be expressed under what circumstances. For example, when you receive a gift that u dislike, u do not show ur disappointment in front of the person who gave u the gift.

emotional self-regulation: strategies for managing emotions or adjusting emotional arousal to an appropriate level of intensity

in early years, caregivers are usually the ones regulating babies emotions

social referencing: use of others' emotional expressions to infer the meaning of situations

emotional competence: competent emotional expressivity, competent emotional knowledge & competent emotional regulation

competent emotional expressivity: being able to show more positive emotions, rather than negative ones

competent emotional knowledge: able to correctly identify other's emotions and the factors responsible for these emotions)

competent emotional regulation: able to manage emotions to appropriate levels to reach one's goals)

social competence: ability to achieve personal goals in social interactions while maintaining positive relationships

Temperament: a person's characteristic modes of responding emotionally and behaviourally to environmental events

influences:

Hereditary:

-biologically related

-genes influence prosocial behaviour and temperament

Home environment

-influences children's positive aspects of temperament

-shared environment contribute little to children's activity levels and negative attributes

culture

cultural beliefs and values

stability of temperament:

-behavioural inhibtiaton: temperamental attribute reflecting one's tendency to withdraw from unfamiliar people

-influenced by deep biological roots

-parenting styles

GOOD FIT IS WHEN PARENTS MATCH THEIR EXPECTATIONS FOR THEIR CHILD WITH WHAT THE CHILD IS ABLE TO DO, BASED ON THE CHILD'S AGE, TEMPERAMENT AND ABILITIES

Stranger anxiety: wary/ fretful reaction that infants and toddlers display when approached by an unfamiliar person

Seperation anxiety: wary/fretful reaction that infants and toddlers display when seperated from people whom they are attached to

attachments:

secure attachment: infant-caregiver bond where child welcomes contact with a close companion and uses this person as a secure base from which to explore the environment. (outgoing even when mother is present)

resistant attachment: an insecure infant-caregiver bond, characterised by stong seperation protest and tendency for the child to remain close but resist contact initiated contact by caregiver, particularly after a seperation. (wary of strangers, even when mothers present)

avoidant attachment: insecure infant-caregiver bond, characterised by little seperation protest and a tendency for the child to ignore and avoid the caregiver. (rather sociable w strangers but may sometimes avoid and ignore them like how they did to their mothers)

disorganised attachment: insecure infant-caregiver bond, characterised by the infant's dazed appearance on a reunion, or a tendency to first seek and then abruptly avoid the caregiver

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Development of the self-concept

self recognition:

-occurs from 18 months onwards

present self- self representation of 2-3 year olds who only recognise current representations of themselves, but are unaware that past self-representations of self or self-relevant events have implication for the present

extended self- more mature self representation emerging between 3 1/2 years to 5 years, in which children are able to integrate past, current and unknown future self-representations into a notion of "self" that endures over time

Contributors:

cognitive abilities:

-making connections with actions like what they can see in the mirror and through their bodily movements

social experiences:

-secure attachment to a primary caregiver

-2-3 year olds tend to respond better

parents:

-provide descriptive information and evaluate the child's behaviour

-ask questions and this helps the children reorganise their experiences

Parenting styles:

-different cultural practices that reflect differing emphasis

Cultural influences in societies

INDIVIDUALISTIC:

-value competition and individual initiative (independent)

-emphasise on individual initiative and differences

eg. australia, canada and america

COLLECTIVIST:

-emphasise on cooperative and interdependence

-identify oneself closely related to the group they belong

eg china, india, japan

Self-concept: how a child views his/her qualities and sense of self

self-esteem: evaluative in nature, and refers to the satisfaction with those qualities comprising his or her sense of self

4-7 years old: inflated self perceptions, tend to rate positively in all domains, desire to be liked or good at various activities instead of a firm sense of self-worth

8 years old: closely reflect on other people's evaluation of them

Social contributors of self esteem:

Parenting styles -> construction of positive/negative working models of self

Peer influences -> use of social comparison (process of defining and evaluating the self by comparing oneself with others)

culture, ethnicity &self-esteem -> Child rearing practices, values & beliefs