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)