Untitled Flashcards Set

Midterm January 28th chapters 1-5

Chapter 1 

Historical views of children and childhood 1.1 

• Plato believed children are born with an innate knowledge of concrete objects like animals, people, and abstractions such as courage love and goodness 

• Aristotle denied existence of innate knowledge, and argued knowledge is rooted in perceptual experience 

• John locke proposed infants were blank slates→ experience moulds children →

• Locke in favour of disciplining and rewarding children to shape behaviour →

• Lockes view challenged by jean-jacques rousseau→

• Rousseau believed newborns have an innate sense of justice and morality that unfold naturally as child grows 

• Rousseau argued parents should be receptive to childrens needs 

• Rousseau vs locke= nature vs nurture 

• Darwin natural selection 

• G stanley hall generated theories of child development based on evolutionary theory 

• Alfred binet devised mental tests

• Frued started to suggest early childhood experiences accounted for patterns of behaviour in adulthood 

• John B watson founder of behaviourism 

• Progress in developmental psychology was halted by world war 2 when child development scientists abandoned research to assist in war effort 

• Applied developmental science: uses developmental research to promote healthy development, particularly for vulnerable children and families 

1.2

• Child development theory definition; an organised set of ideas that is designed ti explain and make predictions about development 

Biological perspective

• Development is rooted in biology

• Maturational theory (Arnold Gesell): child development reflects a specific prearranged scheme or plan within the body → development is simply a natural unfolding of a biological plan

• Gessel encouraged parents to let children develop naturally 

Ethological theory 

• Ethological theory: views development from evolutionary perspective, behaviours are adaptive and have survival value, assumption that people inherit adaptive behaviours 

• ethologists believed individuals are biologically programmed in such a way that means some kinds of learning only occur at certain age →

• Critical period: time when a specific type of learning can take place; before or after the critical period, the same learning is difficult or even impossible 

• Imprinting: creating an emotional bond with mother →

• Eg if geese are removed from mother when they are first born (critical period) and the mother is replaced with a different moving object they imprint on the object. The replacement could even be a human 

Psychodynamic perspective 

Frueds theories

• Psychodynamic theory: development is largely determined by how well people resolve certain conflicts at different ages 

• Id: primitive instincts and drives, frued argues present at birth eg crying for food 

• Ego: practical rational component of personality→ freud says emerges during first year of life 

• Superego: moral agent → emerges during preschool years as children begin to internalize adult standards of right and wrong 

• Frueds work is largely critisized but his theory of early childhood experiences affect development and the idea that children experience what they want to do and what they should do remains respected 

Eriksons psychosocial theory 

• Eriksons psychosocial theory: development comprises a unique sequence of stages defined by unique crisis or challenge → 

• Eriskon proposed development could continue into adulthood 

• The challenge for adolescents is to develop an identity 

Eriksons stages of development

• 1.) Trust vs mistrust (birth to 1 year): child learns to trust caregivers and the world when their basic needs are met consistently→ if needs not met, mistrust develops 

• 2.) Autonomy vs shame and doubt (1-3 years): toddlers learn to develop sense of personal control over physical skills and independence, success leads to autonomy, whole failure and excessive criticism leads to shame and doubt 

• 3.) Initiative vs guilt (3-6 years): children assert themselves more frequently, initiate activities, explore and develop leadership→ if efforts encouraged, leadership grows , if they are punished they feel guilt 

• 4.) industry vs inferiority (6-12 years): children strive to develop sense of competence and achievement in school, social interactions. Success fosters sense of inferiority 

Learning perspective

• Learning theorists believe infants mind is a blank slate 

• Watsons research based on classical conditioning 

• Watson famously applied fear conditioning in children→ would be viewed as unethical today 

• Skinner: studied operant conditioning →

• Operant conditioning: consequences of a behaviour determine whether that behaviour is repeated 

• Skinner proved reinforcement strengthened behaviour and punishment weakened 

• Children can learn without reinforcement or punishment by means of imitation or observational learning eg helping parents with groceries because they saw friend doing so 

Social cognitive theory (albert bandura)

• Albert Bandura developed social cognitive theory → bobo doll study 

• Social cognitive theory: stresses cognition (thinking), in learning, children use reward, punishment and imitation to try to understand their world 

• Imitation is more complex than sheer mimicry eg children more likely to imitate from someone perceived as smart or popular→ when behaviour of smart peers is rewarded it makes sense to mimic 

• Bandura says experience gives children a sense of self efficacy →

• Self efficacy: beliefs about their own beliefs and talents →

• Self efficacy determines what children will imitate → eg a child who believes he is not athletic is unlikely to try imitating hockey skills 

Cognitive developmental perspective (piaget) 

• Cognitive developmental perspective: focuses on how children think and on how their thinking changes as they grow 

• Piaget argued children try to comprehend their surroundings like scientists, their theories being tested by daily experience, when the event the child predicts occurs, their theory grows stronger →

• Children also realise their theories have flaws and radically revise them as a result→ 

• According to piaget radical revising happens in 3 stages of development →

• Age two , age seven and just before adolescence →

• Each stage is characterized by more sophisticated reasoning

Piagets 4 stages of development 

• Sensorimotor Stage (Birth to 2 years): In this stage, infants learn about the world through sensory experiences and motor actions. 

• Preoperational (2-7 years)l: Children begin to use symbols, language, and imagination. They engage in pretend play but struggle with logical reasoning. Thinking is egocentric, meaning they have difficulty seeing things from others' perspectives.

• Concrete operational(7-11 years): Children develop logical thinking about concrete (physical) objects and events. They understand concepts like conservation (e.g., the amount of liquid remains the same despite changing container shapes) and can perform mental operations such as organizing and categorizing.

• Formal operational stage (12 years and up): Adolescents and adults develop the ability to think abstractly, reason logically, and plan for the future. They can consider hypothetical scenarios and think scientifically about problems.

Contextual perspective

• Direct influences are important but they are simply one part of a much larger system → all these institutions fit together to form a →

• Culture: the knowledge attitudes and behaviour associated with a group of people 

• Culture provides context in which child develops and is therefore important source of influence on development  

Vygotskys theory of contextual development 

• Believed every aspect of childs development just be considered around cultural backdrop 

Bronfenbrenners theory of ecological systems

• Developing child is embedded in series of complex interactive systems 

• Ecological systems theory: environment is divided into five components: microsystem, mesosystem, macro system and chronosystem 

• Microsystem” consists of people and objects in immediate environment 

• Mesosystem: what happens in one micro system is likely to affect what happens in others 

• Exosystem: refers to social settings that a person may not experience first hand but still influence development eg mothers work environment is part of childs exosystem 

• Macrosystem: the subcultures and cultures in which microsystem, mesosystem and exosystem are embedded→ attitudes, beliefs, heritage 

• Chronosystem: the idea that these systems are not static and change over time 

• But no single perspective provides a complete explanation for a childs development 

1.3

Continuity of development 

• Once a child starts down a particular path of development , that child stays on that path throughout their life → however some believe you can be a particular way as a child then different as a teenager, then different again as an adult 

• Continuity versus discontinuity: issue concerned with whether developmental phenomenon follows a smooth progression throughout life or whether development is a series of abrupt shifts →

• Neither of these views are actually accurate, development is not perfectly predictable

• Continuity: early development is related to later development but not perfectly 

• Nature and nurture: development is always jointly hereditary and environmental

• Active children: children influence their own development 

• Connections: development in different domains is connected

• piagets developmental theory emphasizes connections 

• Learning perspective argues that degree of connectedness depends on nature of environmental influences  

Impact of nurture and nature 

• What roles do biology and environment play in child development?

• Children can actually shape the way parents parent funnily enough 

• Active passive child issue: are children simply at mercy of their environment (passive child) or do children actively influence their own development through their unique individual characteristics (active child) →

• Passive child view corresponds to locke’s view of a blank slate

• Active child view corresponds to rosseaus view of development as a natural unfolding that takes place within a child 

1.4

Measurement of child development in research 

• Systematic observation: watching children and carefully recording what they do or say→ 2 forms of systemic observation →

• Naturalistic observation: children are observed as they behave spontaneously in a real life situation 

• Structured observation: researcher creates a setting likely to elicit behaviour of interest

• Variables: factors subject to change, to record 

• Nominal scale: involves measuring discrete categories

• Checklist: prepared list of behaviours or characteristics to be noted 

• Observer bias: when researcher tends to notice behaviours that support hypothesis and discount those that do not, or interpret behaviours in such a way that they support the hypothesis 

• Inter-rater reliability check: two observers using the same agreed upon measures perform observations, if their results are roughly the same the inter-rater reliability is good 

• Observer influence: form of participant bias, occurring when participants change their behaviour because they are being observed → habituation can help with this

• Habituation: allows participants to get used to researchers presence 

• Self reports: childrens own response to questions about the topic of interest →

• Response bias: some responses may be more socially acceptable than others and participants, especially children are more likely to select those than socially unacceptable answers 

• Physiological measure: measuring heart rate, eg heart rate slows down when children are listening, eg measuring cortisol levels in saliva to measure stress levels 

Evaluating measures

• Reliable: measure is reliable if results are consistent over time

• Valid: a measure is valid if it really measures what researchers think it measured 

• There are a number of subtypes of validity →

• Construct validity: if a test measures a theoretical construct that it is supposed to→ eg a measure of friendship is valid only if it can be shown to actually measure friendship

• Concurrent validity: when two forms of measurement correspond or concur

• An unrepresentative sample can lead to invalid research 

• Reliable research design: an overall conceptual plan for research; two most common designs are correlational and experimental designs 

• Correlational study: investigators look at relations between variables as they exist naturally in the world 

• Correlation coefficient: abbreviated as r, which stands for the direction and strength of the relation between two variables →

• When r=0 two variables are completely unrelated 

• When r is greater than 0 scores are related 

• When r is less than 0 scores are related but inversely 

• Positive correlation: larger values on one variable are associated with larger values on the second variable 

• Negative correlation: larges values on one variable are associated with smaller values on a second variable 

• Inferential statistics: allow one to draw conclusions 

• Null hypothesis: states that nothing that the experimenter did has had any effect on anything done as part of the experiment

• Field experiment: researcher manipulates variables in natural setting so that results are more likely to be representative of behaviour in real world settings 

• Quantitative researc: adds together many pieces of data 

• Qualitative research: more in depth study of individuals 

Developmental designs

• Longitudinal design: the same individuals are observed or tested repeatedly at different points in their lived → well suited to studying development 

• Microgenetic study: children are tested repeatedly over a span of days or weeks typically with the aim of observing change directly as it occurs 

• Longtitidual approach disadvantages →

• Practice effects: when children are given the same test many times they become test wise → so improvement may be related to practice and not development, changing tests can help with this but makes it hard to compare responses 

• Selective attrition:problems with constancy of sample over time→ some children may drop out because they move away, or because they lose interest 

• Cohort effects: when children in longtiuital study are observed over period of several years, the developmental change may be particular to a specific generation of people known as a cohort

• Cross sectional study: developmental changes are identified by testing children of different ages at one particular point in their development eg researcher might chart differences in particular attribute from age 6, 9 and 12 

• Longitudinal sequential study: includes sequences of samples each studied longitudinally 

• Meta analysis: tool that allows researchers to synthesize the results of many studies to estimate relations between variables 

• Quasi experimental design: includes multiple groups that were not formed by random assignment eg comparing childrens reading levels from different schools, because they children were not assigned randomly to the schools it is quasiexperimental 

Ethical guidelines of CPA or Tri-council 

• Seek research that benefits humanity 

• Minimize risk to research participants 

• Describe the research to potential participants so they can determine whether they wish to participate 

• Avoid deception→ if participants must be deceived a thorough explanation of the true nature of the research must be provided as soon as possible

• Keep results anonymous or confidential 

• Give a debrief afterwards, if deception was used it must be explained before participant goes home 

Chapter 2 

• Chromosomes: thread like structures that contain DNA and proteins 

• DNA (deoxyribonucleic acid): genetic material that is in every cell in your body 

• Genes: segments of DNA, basic genetic material that is in every cell of your body 

• DNA: pairs of nucleotidue base pairs →

• Adenine - thymine

• Guanine- cytosine

• The order of the nucleotide base pairs in the code that causes the cell to create specific amino acids, proteins, enzymes → these are building blocks in the body 

• Essential amino acid for fight or flight;epinephrione 

• Dopamine: brain reward system, mortor control, learning and memory 

• Most cells have 36 chromosomes arranged in 23 pairs 

• The first 22 pairs of chromosomes are autosomes and the 23rd pair are sex chromosomes 

• Gametes: reproductive cells, sperm, egg (oocyte) cells (23 chromosomes each)

• Zygote fertalized egg 

• Genotype: complete set of genes that makeup a persons hereditary 

• Phenotype: a persons physical, behavioural and psychological features- genotype x the environment 

Single gene influence 

• Genes come in different forms → these are called alleles 

• Pairs of alleles can be homozygous or heterozygous 

• Dominant allele= chemical instructions are followed 

• Recessive allele= chemical instructions are ignored (unless both alleles are recessive) 

• Incomplete dominance: one allele doesnt dominate the other completely 

Genetic disorders 

• Many disorders are homozygous recessive- eg cystic fibrosis. Albinism 

• Some disorders are sex linked eg hemophilia 

• Some people are born with too many, not enough or damaged chromosomes 

• Disorders that are caused by missed or extra sex chromosomes: turners syndrome, klinefelters syndrome, 

• Down syndrome: extra 21st chromosome, reasons still largely unknown 

• Behavioural genetics: branch of genetics that studies the effects of hereditary on behaviour, to what extent are our abilities, personalities, sexual orientation, determined by our genes 

• Polygenic inheritance: involves many genes, reflects many behavioural genotypes 

Research designs 

• Twin studies: provide behavioural genetics which clues about the influence of heredity 

• Adoption studies provide behavioural geneticists with clues about the influence of heredity → 

• if an adopted childs behaviour resembles the biological parents this shows impact in favour of heredity → 

• If adopted childs behaviour resembles adoptive parents this shows influence of the environment 

• measure trait of interest among ppl who vary in genetic relatedness

• correlation btwn the measure of the trait in individuals w different degrees of relatedness

• twin-study designs → correlations of pairs of MZ twins and DZ twins

• adoption study designs → correlations btwn child and biological parents and child and child adoptive parents 

Path from genes to behaviour

• Behavioural consequences of genetic instructions depend on the environment in which those instructions develop 

• Reaction range: the same genotype can produce a range of phenotypes in reaction to environment 

• Heritability: behavioural genetics often use correlations from twin and adoption studies to calculate a heritability coefficient 

• Heritability coefficients: estimate the extent to which differences between people reflect heredity → eg . .5 heritability coefficient = 50% of the differences in cognitive ability is due to heredity 

• 5 heritability coefficient = 50% of the differences in cognitive ability is due to heredity 

• Environment and certain experiences can turn on or off genes 

• Epigenisis: continuous interplay between genes and multiple levels of the environment , from cells to culture, that drive development

• Methylation: one of several epigenetic mechanisms that cells use to control gene expression → a chemical reaction in the body in which a small molecule called methyl group gets added to DNA → 

• Eg child abuse aggregated expression of 4 genes → major depressive disorder 

• Niche-picking: deliberitly seeking environments that fit ones heredity → first childhood, increasingly so throughout development 

• Environmental influences within a family are not straightforward→

• Shared environment, growing up together in the same family→ same family = same environment 

• Non shared environment effects: experiences unique to the individual

Relationship between genes and environment 

• Parents genes influences their childrens genes and their childrens environment 

• Childs genes and phenotype interact with their environment

Chapter 3 

Prenatal development- conception at birth 

• Gametes: 23 chromosomes each→ combined during fertilization 

• germinal /zygote: conception to 2 weeks 

• Embryontic: 3rd to 8th week

• Fetal: 9th week to birth 

Period of zygote (weeks 1-2)

• Begins when egg is fertilized in the fallopian tube→ rapid cell division, about 4 days the zygote is called a blastocyst 

• Ends two weeks later when zygote in implanted in wall of the uterus 

• Placenta → formed between mother and developing organism to provide nutrients and remove waste 

Placenta

• Supplies oxygen

•  removes co2

• Filters waste products, supplies nutrients 

• Genetically matches future baby but the bassi is made of maternal tissue

• Biggest gland secrete hormones that support pregnancy 

• Sharing the placenta: doesnt happen with fraternal twins but perhaps with identical twins

Ferocisous biological struggle between mother and baby 

• Endometrium cells are tightly aligned and packed with lethal immune cells 

• what if embryo is placed in another type of tissue? the tissue gets eaten up, the uterus is designed to handle the development of an embryo on its own terms

• enbryo needs to start and keep on sending hormonal signals→ 

• What happens if it doesnt or can’t, it gets kicked (period) 

• 30-45% of conceptions end in miscarriages 

• 15-20% of women dont realise they have miscarried 

• Fetus sends out hormones that spike maternal blood sugar and blood pressure and cortisol 

Period of the embryo 

Week 3-8

• Embryo: a blastocyst that is embedded into the uterine wall 

• Body structures and internal organs formed during this period 

• Three layers →

• Ectoderm: hair, outer layer of skin, nervous system

• Mesoderm: muscles bones and circulatory system 

• Endoderm: digestive system and lungs 

• Umbilical cord joins embryo to placenta 

• Neural tube defects→

• Spinal bifida: birth disorder where the spine doesnt fully develop, neural tubes dont completely closde and some bones of spine dont close →

• Openings can be anywhere along the spine and damage the spinal cord and nerves

• Factors in spinal bifida: folic acid needs to be ingested to prevent the disease, in canada flour is by law enriched with folic acid since 1988 to prevent this birth defect

9- 30-40 weeks

• From 9 weeks after conception to birth  

• Finishing touches are put in the body systems 

• All regions of the brain grow particularly the cerebral cortex 

• Genital organs develop in the 3rd month

• skin is covered w a thick, greasy substance, vernix 

• Age viability: occurs at 22-28 weeks and fetus has a chance to survive 

Fetal behaviour

• By 6 months fetuses show heart rate changes in response to psychological stress →

• The better fetal heart rate variability, the more advanced motor, mental language development at 2 months old 

• Prenatal movement: by 12 weeks after gestatoon, most of the movement that will be present at birth have appeared 

• swallowing the amniotic fluid promotes the normal development of palate and aids in the maturation of the digestive system

• movement of the chest wall - pulling in and expelling small amounts of amniotic fluid help the respiratory system become functional

Prenatal sensation

• Sensory structures are present relatively early in prenatal development →

• fetus experiences tactile stimulation taste and smell

• Responds to sounds around the 6th month of gestation 

• Prenatal visual experience is non existent 

deCasper and Spence (1986) Cat in the hat

•  7 1/2 month pregnant women read the story aloud twice a day newborns tested using nonnutritive sucking procedure some heard mother read storied, others hear unfamiliar woman read stories control 

• infants who’s mothers hadn’t read the stories during pregnancy findings preferred mothers reading the story, and if they heard the story while in the womb 

Influences on prenatal development

• Prolonged stress: decreased oxygen to fetus, weakens mothers immune system, leads to unhealthy behaviours of mother eg smoking or drinking

• Lower birth weight

• Premature birth

• Newborn irritability 

• Feeding and sleeping problems during infancy 

• Behaviour issues at the age of 4 years 

• Nutrition →

• Thirds trimester is critical period for receiving nutrition, minerals etc 

Covid and pregnancy

• covid-19 was associated with preeclampsia, preterm birth, stillbirth

•  severe, vs mild, covid was associated with preeclampsia, preterm birth, gestational diabetes and low birth weight 

• so far, no concerns regarding vaccination during pregnancy 

• also, no neurodevelopment abnormalities associated with exposure ot covid in utero 

Influences on prenatal development 

• Teratogen: an agent that causes abnormal development

• Many diseases pass through the placenta directly attack the fetus and others attack at birth

• Caffeine and arpirin potentially dangerous, not in small amounts but best to avoid anyways 

• Thalidomide: severe harm to children, drug for anxiety, insomnia and morning sickness, led to greater drug regulation 

• nicotine cigarette smoking is linked to growth and low birth weight constricts blood vessels in the placenta → 

• linked to sids (sudden infant death syndrome) and adhd

Alcohol

• Fetuses dont have fully developed livers → so cannot break down alcohol and it stays in their system for longer

• Kills cells in different parts of the fetus→ leading to abnormal physical development 

• Interferes with development of central nervous system 

• Constricts blood vessels which interferes with nutrient supply to the placenta 

• Risk of miscarriage, premature birth or low weight 

• Alcohol affects central nervous system the most 

Fetal alcohol spectrum disorders (FASD) 

• Fetal alcohol syndrome: most severe condition on the spectrum →

• Abnormal facial features

• Low weight 

• Small head 

• Abnormalities of brain development that can cause seizures 

• Language or learning problems and or intellectual disability 

• High risk for ADHD, intellectual disability, impulsive behaviours and language and learning problems 

• Prevalance in north america 8% →

• 4% in canada → 1/9 preganant people drank alcohol in the last 30 days 

Birth 

• labour stage 1 - starts when the muscles of the uterus contract and ends when the cervix is fully enlarged (10 cm) 

• stage 2 - baby is pushed through the birth canal

•  stage 3 - placenta is expelled

• why born at 9 months: underdeveloped heads compared to other primates would take 21 months to get there → 

•  trade off between bigger heads and smaller pelvis that we need for  walking

•  perhaps metabolism: by 6m pregnant ppl expend x2 energy 

Birth complications

• Hypoxia: can occur during labour and delivery if the umbilical cord is pinched or squeezed shut cutting off blood flow to the baby 

Reasons for c section 

• breech presentation, 

• shoulder presentation syphilis,

•  herpes simplex, aids 

• previous c-section 

• multiple births genetic basics, 

• fetal distress

Post partum depression (PPD)

• Most common complication of childbirth 

• Outcomes are severe and include suicide risk→ suicide accounts for 20% of post partum deaths 

• For infants PPD impairs infant safety and development → leads to infantile colic and poor maternal and infant bond 

• the effects of ppd are further compounded, eventually affecting IQ, language development and behaviour 

apgar test 

• assesses five vital signs in the newborn 

• appearance (skin tone) 

• pulse (heart rate)

•  grimace (presence of reflexes) 

• activity (muscle tone)

•  respiration (breathing)

Newborns reflexes

• Prepare them to interact with the world 

• Some reflexes important for survival eg sucking 

• Some protect baby eg blink and withdrawal

• Some are foundation for later motor behaviour eg walking and stepping 

newborn states

•  alert inactivity: calm and attentive, eyes open 

• waking activity:  eyes are open but unfocused, arms and legs are moving in bursts of uncoordinated motion

•  Crying

•  sleeping

Newborn sleep

• 16-18 hours daily cycles of wakefulness and sleep every 4 hours (1h sleep, 3h awake) 

• REM sleep 50% of a newborn’s total sleep time (up to 80% in premature infants “Active” sleep declines to only 20% by 3 or 4 years of age

SUID

• occurs when a healthy baby dies for no apparent reason

•  includes all unexpected deaths: suffocation and those w/o a known cause (ie. SIDS, sudden death syndrome) 

• risk factors: premature/low birth-weight, prenatal smoking, babies sleeping face down, being too hot while sleeping

Chapter 4 

4.1

Physical growth 

• Growth follows two distinct trends→

• Cephalocaudal: head to tail →

• Proximodistal: from close in to farther out 

• Head and trunk grow faster than legs 

• infants / toddlers have disproportionately sized heads 

• During pre school children become leaner, but in early elementary years they start to gain fat again 

• Increased fat in adolencense is more prominant in girls 

• Bones begin to form during prenatal period, starting as cartilage 

• During embryonic period, centre of tissue turns to bone 

• Epiphyses: cartilage structures that form shortly before birth then turn to bone 

• Today adults and children are heavier than in previous generations → largely due to improved nutrition 

• Secular growth trends: changes in physical development from one generation to the next 

• Average physical growth also varies from one country to another 

• Average and normal are not the same, many children are taller than average and perfectly normal 

Nutrition

• Breast feeding best way to nourish infants 

• Mothers breastmilk contains antibodies that kill bacteria and viruses

• Breastfed babies are less prone to bowel issues and can transfer to solid food earlier 

• Experts recommend breastfeeding continue until 2 years old 

• Most pre schoolers need 1,500- 1,700 calories 

• Picky eating in young children may be adaptive, they dont know what food is safe to eat and what isnt so choose to eat foods they find familiar 

• Virtually all picky eaters get adequate food for growth 

• Measures for helping picky eating; reward children, show pictures of other children eating the food, teach children about nutrition, offer children new foods one at a time and in small amounts 

Adolescent growth spurt and puberty

• Puberty: adolescent growth and sexual maturation 

• Girls typically begin growth spurt 2 years before boys 

• Girls typically reach growth spurt at 11 and peak at 12 

• During growth spurt; bones become longer and denser, muscle fibres become thicker (more pronounced in boys) 

• Primary sex characteristics: organs that are directly involved in reproduction 

• Seconday sex characteristics: physical signs of maturity not lunked directly to the reproductive organs 

• Menarche: onset of menstruation→ typically at age 13 

• Spermarche: first spontaneous ejactulation of sperm-laden fluid 

• Osteoporosis usually has roots in adolescence if children do not consume enough calcium 

Mechanisms of maturation

• Pituitary gland regulates pubertal changes by signaling other glands to secrete hormones 

• Pituitary gland sends signals for ovaries to release estrogen in girls

• Pituitary gland signals testes to release androgen testosterone 

• Timing of pubetal events is regulated partly by genetics 

Psychological impact of puberty

• Adolescents much more concerned with how they look than children and adults 

• Maturing late or early can be psychologically harmful 

• Girls who mature early are less confident, less popular and more likely to be depressed and drink or smoke 

• Early maturation can lead girls to enter relationships with older boys and are ill prepared to cope with demands of relationship →

• Can lead to teen pregnancy 

• Early maturing boys are at risk for psychological disorders eg depression and prone to substance abuse and early sex →

• Early maturing boys can spend time with older boys → which in turn exposes them to risky behaviours 

4.2 

Challenges to healthy growth 

• Malnutrition: inadequate nutrition that causes one to be small for ones age 

• When children eat breakfast they are more likely to do better in school 

• Anorexia: disorder marked by persistent refusal to eat and an irrational fear of being overweight 

• Bulimia: alternate between binging and purging

• Boys make up only 10% of eating disorder cases → eating disorder more commonly associated with boys →

• Body dysmorphic disorder: individuals are not satisfied with their body shape or the shape of a particular part of the body, perceived muscularity is often the focus

• Children in upper 5 percent (heavy for height) are considered overweight

• Obesity on the rise in canada→ 18% of adults now obese 

• Obese children likely to become obese adults 

• Factors contributing to obesity: genetics. Parents pressuring children to clear their plate,, parents using food to comfort children who are upset, sedentary lifestyle, too little sleep 

Disease

• Five conditions leading killers of young children world wide: pneumonia, diarrhea, measles, malaria and malnutrition 

• IMCI: integrated management of childhood illnesses 

4.3 

developing the nervous system 

Organization of the mature brain 

• Neuron: basic unit of the brain and the rest of the nervous system, a cell that specialises in receiving and transmitting information 

• Cell body: at the centre of the neuron, contains the basic biological machinery that keeps the neuron alive →

• Dendrite: end of neuron that receives information

• Axon: tube like structure at other end of the cell body → axon is wrapped in →

• Myelin: fatty sheath that allows the axon to transmit information more rapidly

• Terminal buttons: small knobs at the end of the axon which release neurotransmitters

• Neurotransmitters: chemicals that carry information to nearby neurons 

• Synapse: the gap between one neuron and the next 

• The wrinkled surface of the brain is the cerebral cortex, made up of 10 billion neurons →cortex consists of left and right halves called hemispheres, that are linked by →

• Corpus collum: thick bundle of millions of axons connecting the 2 cerebral hemispheres 

•  your personality and ability to make and carry out plans are functions of the frontal cortex →

• Frontal cortex: a brain region that regulates personality and goal directed behaviour 

The developing brain 

• Neural plate: a group of cells present in prenatal development that become the brain and spinal cord, flat structure 

• Production of neurons begins about 10 weeks after conception 

• In fourth month of prenatal development axons begin to acquire myelin 

• Synaptic pruning: gradual loss of unused synapses beginning in infancy and continuing into early adolescence →

• Brain downsizes and weeds out unnecessary connections between neurons 

• EEG(electroencephalogram): measuring brain electrical activity using electrodes placed on the scalp

• fMRI( functional magnetic resonance imaging): uses magnetic fields to track the flow of blood in the brain 

• Specialisation: the kinds of stimuli that trigger brain activity switch from general to specific, think of a thunderstorm covering a large region versus concentrated in much smaller region →

• Different brain systems specialise at different rates eg think of floors when renovating a house, perhaps the first floor is completed before the upstairs →

• Brain regions involving basic sensory and perceptual processes specialise first

• Successful specialisation requires stimulation from the environment 

• Experience expectant growth: changes in the brain from environmental influences that typically occur in specified points of development for all children → a developing brain depends on 

• over course of evolution, infants typically have been exposed to forms of stimulation that are used to adjust brain wiring, strengthening some circuits and eliminating others 

• Experience dependent growth: changes in the brain caused by experiences that are not linked

• Brain development usually follows a predictable course that reflects epigenetic interactions between the genetic code and environment 

• There are limits to plasticity eg experiences later in a childs development cannot erase or compensate for deprivation at care they received at orphanage 

Chapter 5

5.1 

Basic sensory and perceptual experiences

• Newborns have keen sense of smell 

• Infants do not hear as well as adults→

• Auditory threshold: the quietest sound a person can hear ( adults have higher auditory threshold than infants 

• Visual acuity: the smallest pattern that can be distinguished reliably 

• Infants begin to see world with greater acuity and colour within the first year 

• Cones: neurons in the back of the eye that detect colour 

• Babies can detect relations between information presented visually and auditorally 

• Babies can link their own body movement to their perceptions of musical rhythm 

• Amodal: information such as duration, rate or intensity that is not restricted to a single mode of presentation and can be presented at different senses 

• Intersensory redundancy theory: the infants perceptual system is particularly attuned to amodal information that is presented to multiple sensory modes → perception is best when information is presented to multiple sources 

5.2 

Percieving objects 

• Newborns perception of objects develop rapidly in first few months after birth 

• By 4 months infants use a number of cues to determine which elements go together to form objects→

• Important cue is motion, elements that move together are usually part of the same object 

• Perceptual constancies →

• Size constancy: the realisation that an objects actual size remains the same despite changes in the size of its retinal image 

• Depth, in addition to knowing what an object is babies need to know where it is 

• Many cues are needed to estimate depth 

• Visual cliff: glass covered platform that appears to have a shallow side, used to study infants depth perception 

• Kinetic clues: motion is used to estimate depth 

• Visual expansion: the fact that as an object moves closer it fills an even greater proportion of the retina 

• Motion parallax: the fact that nearby moving objects move across our visual field than those at distance 

• Retinal disparity: important at 4 months of age, based on the fact that the left and right eyes often see slightly different versions of the same scene 

• By 7 months infants use several cues for depth that depend on arrangement of objects in environment→

• Pictorial cues: cues for depth that depend on the arrangement of objects, these cues are used by artists to depict depth in paintings 

• Motor skills can affect perception of development because infants who explore objects are more likely to understand the 3 dimensional nature 

5.3

Motor development 

• Locomotion: the ability to move about in the world 

• Infants must learn fine motor skills →

• Fine motor skills: grasping, holding and manipulating objects 

• In a little over a year locomotion allows newborns to go from being stationary to upright 

• By about 4 months babies can sit up without support 

• toddlers ; name comes from toddling manner of early walking

• Dynamic systems theory: motor development involves many distinct skills that are organised and reorganised over time to meet the demands of specific tasks 

• Only with growth of legs and muscles can infants maintain upright posture because of heavy head 

• Infants must relearn balancing for sitting, crawling, walking and other postures 

• Infants use environmental cues to determine whether an environment is safe for walking eg bumpy hill vs at home flat floor or when walking down stairs, is the particular step is too large to desend safely 

Coordinating skills

• Mastery of intricate motions requires→

• Differentiation: mastering individual skills →

• Integration: combining them in proper sequence into a coherent working whole 

Fine motor skills 

• Reaching and grasping: happens at 4 months, reaching requires infant move hand to desired location, and grasping requires infant to coordinate movements of individual fingers to grab an object

• Some scientists believe a gene biases children toward being right handed →

• Experience contributes, the world is set up for right handed people 

• Fine motor skills can make it easier for children to exercise which has physical health benefits 

• Erosion of outdoor play in children is a health concern 

• CHEO has found that more time playing outside = better psychosocial outcomes