Lecture 2 Flashcards
What is nature?
Biology/Heredity/Maturation
What is nurture?
Environment (e.g., Locke -> tabula rasa)
What is nature specifically relating to?
Maturation - Natural growth that unfolds in a fixed sequence independently of the environment
Who spoke of this?
Gesell
What spoke about nurture?
Watson
What is nurture specifically related to?
Behaviour - that is all learned
What is the current contemporary approach?
The current argument in developmental psychology is that heredity (biology) creates predispositions that interact with environmental influences (family, friends, teachers, media, random events).
What is the percentage that comes from genes and environment?
It cannot be ascertained how much nurture contributes and much environmental contributes
Why is the percentage argument difficult?
- Need to differentiate simple VS complex characteristics (height vs intelligence)
- Reciprocal interaction between nature and nurture -> heredity and environment are correlated, e.g., intelligence
- Children are “niche pickers” -> they actively choose environments that bets suit their genetic predispositions
What happens in prenatal development?
Process of development begins when sperm fertilizers an ovum (or egg cell) - A new cell nucleus is created from the genetic material provided by male and female
What is a zygote?
One celled organism, produced by union of sperm and an ovum
What are the stages of prenatal development?
There are three stages of prenatal development;
Germinal stage
Embryonic stage
Foetal stage
When is the germinal stage?
Fertiliziation to two weeks gestation
Once the zygote begins to divide 24-36 hours after fertilisation, it travels down the fallopian tubes to the uterus
A blastocyst is formed (150 cells), attaches to the walls of the uterus and is fully embedded in the wall of the uterus.
What happens in the embryonic stage?
Two weeks gestation to two months gestation (i.e., week 3 to week 8 after conception)
Rapid development of major organs (e.g., heart, nervous system, stomach, sex organs).
What stage does the placenta begin?
The Embryonic Stage
What does the placenta do?
Transports nutrients from mother to foetus
Carries wastes from foetus to mother
Screens out potentially harmful substances, especially bacteria
By the end of the embryonic stage, what happens to the embryo?
Measures 2.5cm in length
Develops eyes, ears, nose, jaw, mouth, lips, arms, hands, fingers, legs, feet, toes
When is the foetal stage?
Two months gestation to nine months gestation
What happens in the foetal stage?
Around six months gestation (i.e., from approx. week 24 or 25 after conception)
Eyelids open
Foetus can breathe regularly for 24 hour length periods
Viable (but not guaranteed) of surviving outside the womb
Eight months gestation (i.e., from approx. week 32 or 33 after conception):
Responds to light and touch
Learning occurs - habituation
What are some of the factors that affect prenatal development
The timing and stages of prenatal development are:
Biologically determined, but also affected by the environment in the womb (i.e., the environment)
Effects of teratogens especially important
What are teratogens?
External substances that can penetrate the placenta, resulting in spontaneous abortion or birth defects
Most likely to affect development when ingested during the period of rapid organ development and differentiation, known as the critical period
What are some examples of teratogens?
Bacteria and protozoa (raw meat/fish, cat feces) with effects such as blindness, deafness, intellectual disabilities
Virus (Rubella etc., examples blindness, deafness, intellectual disabilities, heart defects, cerebral palsy)
Cytomegalovirus (CMV) flu like symptoms, Herpes Simplex (C-section is recommended)
HIV/AIDS
Maternal drug use:
Increases mothers risk of miscarriage, still birth and prematurity, increases risk for SIDS and contributes to slower than average cognitive development, attention deficits, hyperactivity, conduct problems
Maternal drug use (Alcohol) Foetal Alcohol Spectrum Disorders - collection of congenital (inborn) problems, etc.
What are some other examples of teratogens?
Maternal nutrition
Environmental toxins and hazards
Emotional stress
Discuss newborn physical development, what are the two factors?
The physical body grows rapidly from birth throughout infancy;
Weight: 3kg at birth, infants weight doubles by 4 months, gradual weight increase to 2 years as bones and muscles grow.
Length: Babies gain 2.5cm per month for each of the first 12 months
By infancy’s end, 2 year olds achieved;
50% adult height
20% adult weight
Brain undergoes massive development and grows: 2 years old; 75% of adult brain weight
What are four of the five modalities of sensory abilities of infants development?
Sight
Hearing
Smell
Taste
Discuss newborn vision:
Newborn vision is blurry
Able to see large objects at close range
Stare longest at objects that have qualities and contours resembling those of a human face
What age does depth perception develop?
7 months
Discuss newborn vision:
Newborn hearing is poor
Infants, though will turn their head toward sound
They can also detect difference between tones one note apart on musical scale.
Discuss newborn hearing:
Hearing attuned to sounds of speech with a preference for:
Rising tones (women/children; men tend to use the same tone of voice for infants, children and adults).
High pitched, exaggerated, expressive speech (parentese)
Hearing does not develop adult-like acuity until childhood
Discuss newborn smell
Newborn sense of smell is similar to adults although less acute;
Preferences for;
- Flower smells
- Smell of own mother
- Dislike of ammonia smells
Discuss newborn taste:
- Sweet drinks (can discriminate between tastes after two hours of birth)
- Food flavours consumed by the mother
What does motor development refer too?
Refers to the progression of muscular co-ordination required for physical activities
What are the two types of motor development?
Gross motor
Fine motor
Define gross motor skills:
Standing, sitting, walking
Define fine motor skills:
grasping and reaching for objects, manipulating objects
What are the two principles that guide motor development?
Cephalocaudal trend and proximodistal trend
What is the cephalocaudal trend?
Head to foot direction of motor development
What is the proximodistal trend?
Centre outward direction of motor development (gain control over trunk before extremities.
What is an important aspect of newborn motor development?
Reflexes
What are reflexes?
Involuntary, unlearned motor behaviours that occur in response to external stimuli
What are some examples of reflexes?
Palmer grasp
Rooting
Moro (Startle reflex)
What month does the reflex start to disappear?
3 months - if they persist after 3 months of age, it may indicate issues with neurological development
What is the Babinski reflex?
Issues with the pyramidal tract
What does did Gesell say?
Motor abilities develop spontaneously in the same order at approximately the same rate - based on his observations of how people develop motor skills biological process behind motor development.
This is a consequence of maturation
When does an infant lift their head?
2.5weeks
When does an infant roll over?
2.5months
When does an infant sit?
5.5months
When does an infant stand alone?
11.5months
When does an infant walk alone?
12.5months
What are the variations?
Up to 2-4months
What age is early childhood?
2 - 6 years
What happens in this stage?
Motor development stage
Is it slower or faster growth than during infancy?
Slower
What is the height and weight discrepancies in this age gap?
6 - 8cm in height between 2 - 6 years and 2 - 3kg in weight between 2 - 6 years and this is per year
Do girls and boys grow at similar rates during childhood?
Yes although there is a shift with growth trajectory
At 3 / 4 / 5 years old what are the gross motor skills and locomotor skills?
3 - runs forward easily, climbs without help
4 - stops, starts and turns while running
5 - Descends stairs without help, hops on one foot for up to 5 metres, walks on tiptoe
At 3 / 4 / 5 years old what are the motor coordinations skills?
3 - Kicks a ball forward, can jump about 30 centimetres
4 - Pedals and steers a bicycle, jumps about 60 centimetres, climbs ladders
5 - Catches balls, rocks on a swing, rides bike well
What 3 / 4 / 5 are the fine motor and manual dexterity skills?
3 - Stacks blocks and picks up marbles, can hold pencil to make marks
4 - Draws with a pencil, cuts paper with scissors, strings beads
5 - Copies simple shapes with a pencil, threads a needle, ties simple knots
What is the growth heigh and weight in middle childhood?
Yearly increase and weight gain of 6cm and 2.25kg
What happens in delicate fine motor control and co-ordination?
Gains in these areas, necessary for artistic, musical, and athletic accomplishments
What is a prominent trend in middle childhood?
Brain approaches full adult size early in middle childhood - at age 6 brain has 90% adult volume - additional 10% that occurs in middle childhood is crucial, as it contributes to plasticity of human brain
What are two risks to optimal physical and motor development in childhood?
Nutritionally deficient diets and obesity
What are the topics surrounding obesity?
Obesity has a significant social and psychological consequences;
Fat prejudice;
Overweight children
What are the ages of adolescents?
13 - 20 years old
What happens in adolescence?
- Learning to live in an adult body
- Profound changes in physical development which affect developments in cognition and personal psychology
- Puberty
What is the only universal changes of adolescence?
Pubertal changes
What is puberty?
- Physical maturation of child into adult capable of reproduction
- Triggered by hormonal changes
- Regulated by the endocrine system (glands, hormones)
What does it involve?
- Growth of the reproductive organs
- Changes in body/fat distribution
- Onset of menstruation in women (menarche)
- First ejaculation of sperm in males (spermarche)
- Pubertal changes take from 2 years to 4 years to complete
What did Tanner (1968) describe?
Tendency for puberty to begin at earlier ages than in previous generations
What does the secular trend involve?
- Decrease in the age of menarche, ages has dropped by 3 to 4 months, increase in growth rate, increase in height and weight
Why is it believed that the secular trend has resulted from?
Improved nutrition, better childcare and knowledge of childhood illnesses and improved sanitation, possibly growth hormones due to eating products such as chicken (growth enhanced hormones?)
What are the effects of pubertal timing?
Differences in the rate of physical maturation at puberty; psychologically, developmentally etc.
What are the three models that account for the effects of pubertal timing?
Deviance hypothesis (supported)
Stage termination hypothesis (partial support)
Adult status hypothesis (partial support)
What is body image?
Self-evaluation that the individual makes of his/her own body
What is the multidimensional construct comprising evaluation of?
Weight
Muscularity
Body strength and conditioning
Shape and size of various bodily parts
What are the two components of body image?
Perceptual
Affective
What does perceptual mean?
What we see
What does affective mean?
How we feel about what we see (also known as body esteem)
What are the specifics on body image around females?
Based on amount of body fat, consistently worse than males body image
What are the specifics on body image around males?
Based on amount of body fat + muscularity, previously more positive but rates of eating disorders rising
What are the three unique stages of lifespan, each with their own biological, cognitive and social changes?
Early adulthood - 20 years - 39years
Middle adulthood - 40 - 64 years
Late adulthood - 65+ years
What happens in early adulthood?
Physical growth continues, increases in shoulder width, height and chest size
What happens in middle adulthood?
Most common physical change - loss of sensory sharpness, hearing loss, less sensitive to light, increased farsightedness
Menopause in women, cessation of menstrual period 45 - 55 years
What happens in the menstrual period?
Gradual lowering of oestrogen levels in bloodstream, decreased fertility and few ova produced
What are the symptoms of menopause?
Hot flashes, dizziness, headache, weight gain, increased risk for heart disease, decrease in bone mass, osteoporosis (also significant risk for men)
What happens in late adulthood?
Decreases in heigh from thinning cartilage between vertebrae
Hardening of arteries and build up of fat on artery walls, digestive system slows and becomes less efficient, decrease in brain size and blood flow to the brain
What are the five theories for explaining the physical changes of old age?
Evolutionary theory Cellular clock theory Free-radical theory Mitochondrial theory Hormonal stress theory
What is evolutionary theory?
Benefits conferred by evolutionary selection decrease with age, therefore natural selection has not eliminated many harmful conditions and non-adaptive characteristics in older adults. Natural selection is linked to reproductive fitness, present only in earlier part of adulthood
What is a disease example of evolutionary theory?
Alzheimer’s Disease - as it is irreversible brain disorder that appears mid to late adulthood, if it occurred earlier in development it may have been eliminated many centuries ago
What is the cellular clock theory?
Hayflick (1977) Cells can divide a maximum of 75 to 80 times, as humans age, cells become less capable of dividing, limit to human lifespan and it all depends of telomeres
What are telomeres?
DNA sequences that cap chromosomes, each time a cell divides, telomeres become shorter, after 70 to 80 replications, telomeres are so reduced, cell can no longer reproduce - cell death
Lifespan length - maximum life of cell
What research supports cellular clock theory?
Injecting enzyme telomerase into human cells grown in the laboratory substantially extends life of cells beyond 70 to 80 normal replications
What are the issues to cellular clock theory?
Issues: Telomerase is present in approximately 85% of cancerous cells, may not produce healthy life extension of cells
What is free-radical theory?
When cells metabolise energy, by products include free radicals (i.e., unstable oxygen molecules).
Free radicals bounce around cells and damage DNA and cellular structures
Damage leads to range of disorders
What are some of the disorders free-radical theory relate too?
Cancer and arthritis
What is the support to free radical theory?
Free radical increase associated with over-eating, low calorie diet that maintains nutrients reduces oxidative damage caused by free radicals
What is mitochondrial theory?
Mitochondria theory is the minute bodies within cells that supply energy for cell function, growth and repair, where there is a decay in mitochondria there is ageing and a decay in mitochondria is caused by oxidative damage by free radicals, loss of critical micronutrients supplied by cell.
What are some of the defects in mitochondria that are associated with mitochondrial theory?
Cardiovascular disease, neurodegenerative diseases; e.g., Parkinson’s Disease and dementia, decline in live functioning
What is the issue with mitochondrial theory?
It is not known if defects in mitochondria cause ageing or accompany ageing process.
What is hormonal stress theory?
When individuals experience stressors, body responds by releasing hormones (adrenaline, corticosteroids). As an individual ages, these hormones remain at elevated levels for longer than when younger
What is the human stress response in relation to hormonal stress theory?
Fight/Flight response activated, adrenaline, noradrenaline and cortisol released, heart rate increases, breathing, fats and glucose released for energy, blood flow diverted from non-essential body areas to muscles and brain, perspiration increased and immune system suppressed, threat removed, acetylcholine released, adrenaline, noradrenaline and cortisol levels lower, body returns to normal.
What is the research to support hormonal stress theory?
Prolonged, elevated levels of stress-related hormones associated with increased risk for many diseases e.g.,
cardiovascular disease, cancer, diabetes, hypertension.
What are the issues with cellular clock theory?
Telomerase is present in approximately 85% of cancerous cells, may not produce healthy life extension of cells.
What is the current research re: cellular clock theory?
Gene therapies that lead to death of cancerous cells while maintaining lifespan of healthy cells
