Developmental Psychology 144
● Development = sequence of age-related changes that occur from conception to death
● Both biological & behavioural processes take place - they’re predictable, related to age
Prenatal Development
● This includes conception to birth, usually 9 months
● This occurs extremely rapidly
The Course of Prenatal Development
3 phases:
○ Germinal stage (1st 2 weeks)
○ Embryonic stage (2 weeks - 2 months)
○ Foetal stage (2 months - birth)
Germinal Stage
● This = 1st phase of prenatal development
● Zygote created w. Fertilisation , rapid cell division occurs within 36hrs
● Cell mass moves along fallopian tube → uterine cavity
● On day 6, cell mass implants to the uterus wall (process takes abt. a week)
○ Less than ½ of zygotes implant successfully
● Placenta begins to form during implantation → allows O2 & nutrients to pass from mother to
foetus from mom’s bloodstream. Bodily waste leaves through mom
Embryonic Stage
● This = 2nd stage of prenatal development, from 2 weeks to end of 2nd month
○ Most vital organs + bodily systems begin forming (embryo)
○ Heart, spine + brain emerge gradually as more cell division takes place
○ Limbs are distinguishable
● If anything interferes with normal development, miscarriage could occur or birth defects
Foetal Stage
● This = 3rd stage of prenatal development, from 2m to birth - now called foetus
● Physical movements are possibles due to hardening of skeletal structures
● Organs continue to grow & function (e.g. hearing around 20-24 weeks)
● Brain cells multiply briskly around 6m, fat deposited under skin (insulation), respiratory
system matures & CNS gains control over bodily functions
● Threshold of viability - around 23/25 weeks it can survive premature birth
○ 23 weeks, survival rate = slim (abt. 24%)
○ 25 weeks, survival rate higher (abt. 72%)
● Premature around 20-24 weeks = 42% show neurodevelopmental impairment & 19% show
sensory deficits around 18-22m of age
,Environmental Factors & Prenatal Development
Nutrition
● Foetus needs essential nutrients to grow + maternal malnutrition increases the risk of birth
complications & neurological deficits
● Malnutrition is difficult to study due to other risk factors like poverty, drug abuse, limited
access to health care, etc.
● A balanced diet is essential, including all essential vitamins + minerals
Stress & Emotion
● Emotions in response to stressful events DO impact prenatal development
○ Elevated prenatal stress = associated w. Increased stillbirths, impaired immune
response, heightened vulnerability to infectious diseases, slowed motor development
+ below average cognitive development
● The emotional reactions disrupt the hormonal balance of the mother
Drug Use
● Most drugs consumed by pregnant women slip through membranes of placenta
○ Basically all recreational drugs = harmful, esp. Sedatives, narcotics, cocaine + meth
● Babies can be born addicted to these drugs with increasing stats (already high, 21k n US per
year)
● Over-the-counter medication = also bad. Tobacco can be problematic as smoking increases
risk of miscarrying, sudden infant mortality, premature labour & stillbirths
● Longer term maternal smoking linked to poor self-regulation, deficits in academic
achievement + increased risk for psychological disorders
● Difficult to determine root causes due to other risky behaviours + genetic predispositions
Alcohol Consumption
● Heavy drinking can be hazardous to the foetus
● Foetal alcohol syndrome = collection of congenital (inborn) problems associated with
excessive alcohol use during pregnancy
● Problems include: microcephaly (small head), heart defects, hyperactivity, delayed motor
development + impaired cognitive development with academic difficulties
● Moderate drinking in pregnancy can have substantial negative effects
○ Increased risk for deficits in IQ, motor skills, attention span, impulsivity, antisocial +
delinquent behaviour
Maternal Illness
● This may be caused by infectious agents entering through the placenta (rare)
○ Measles, rubella, syphilis & chickenpox
● Amt. of damage depends on when mother contracts illness
● HIV causing AIDS can be transmitted from mother to offspring & AIDS prenatally through
the placenta during delivery, placenta or breastfeeding
● Antiviral drugs + cautious obstetrical care reduced transmission rates in modern world
, Environmental Toxins
● There are many environmental toxins that may affect prenatal development
● E.g. air pollution has been linked to cognitive development at 5yrs + increased obesity at 7yrs
+ social competence deficits in middle childhood
● Exposure to phthalate chemicals for household products relates w. IQ deficits of 6-7pts at 7yrs
Foetal Origins of Adult Disease
● Mothers’ experience to adverse events in pregnancy may cause easier susceptibility to
illnesses after birth
○ E.g. prenatal malnutrition = linked to schizophrenia, emerging in late adolescence &
early adulthood
○ E.g. low birth weight linked to increased risk of heart disease in later adulthood
● Prenatal development could also cause risk of depression, bipolar disorders, obesity, diabetes
+ some cancers
○ Genetic vulnerabilities may cause this + stress may cause genetics passed to offspring
Motor, Social & Language Development in Childhood
Motor Development
● Def - progression of muscular coordination required for physical activities
○ Basic motor skills= grasping, reaching, manipulating objects, sitting up, crawling,
walking + running
● Walking was mainly focused on + experience mastered with short walking bursts including
falls and may walk 14k steps per day which improves walking skills
● Early motor development depends mostly on physical growth + very uneven, sudden bursts
○ Growth spurts usually accompany w. Restlessness, irritability + increased sleep
○ Early skills has been attributed mostly to maturation
■ maturation = development that reflects the gradual unfolding of one’s genetic
blueprint, genetically programmed with age rather than experience = learning
○ New research: infants = active agents, not passive organisms waiting for limbs +
brain to mature. Ongoing exploration is the force behind development at infant level
Understanding Developmental Norms
● Developmental norms indicate the typical (median) age that individuals display various
behaviours and abilities
○ They’re benchmarks and shouldn’t be measured exactly to the day
● These norms should be looked at as group averages + variations are normal
○ The averages show at which age the child should exhibit 25%, 50%, etc motor skills
○ A large portion of kids don’t achieve these norms until long past the average norm
Cultural Variations & Their Significance
● Cross-cultural research shows the dynamic relationship btw experience + maturation in dev
● Rapid motor development has shown in certain cultures that provide special practice
○ E.g. Kipsigis people of Kenya teach their kids motor skills right after birth so
milestones are reached quicker (abt. a month earlier)
○ Slow development occurs in cultures that discourage motor exploration
● Development = sequence of age-related changes that occur from conception to death
● Both biological & behavioural processes take place - they’re predictable, related to age
Prenatal Development
● This includes conception to birth, usually 9 months
● This occurs extremely rapidly
The Course of Prenatal Development
3 phases:
○ Germinal stage (1st 2 weeks)
○ Embryonic stage (2 weeks - 2 months)
○ Foetal stage (2 months - birth)
Germinal Stage
● This = 1st phase of prenatal development
● Zygote created w. Fertilisation , rapid cell division occurs within 36hrs
● Cell mass moves along fallopian tube → uterine cavity
● On day 6, cell mass implants to the uterus wall (process takes abt. a week)
○ Less than ½ of zygotes implant successfully
● Placenta begins to form during implantation → allows O2 & nutrients to pass from mother to
foetus from mom’s bloodstream. Bodily waste leaves through mom
Embryonic Stage
● This = 2nd stage of prenatal development, from 2 weeks to end of 2nd month
○ Most vital organs + bodily systems begin forming (embryo)
○ Heart, spine + brain emerge gradually as more cell division takes place
○ Limbs are distinguishable
● If anything interferes with normal development, miscarriage could occur or birth defects
Foetal Stage
● This = 3rd stage of prenatal development, from 2m to birth - now called foetus
● Physical movements are possibles due to hardening of skeletal structures
● Organs continue to grow & function (e.g. hearing around 20-24 weeks)
● Brain cells multiply briskly around 6m, fat deposited under skin (insulation), respiratory
system matures & CNS gains control over bodily functions
● Threshold of viability - around 23/25 weeks it can survive premature birth
○ 23 weeks, survival rate = slim (abt. 24%)
○ 25 weeks, survival rate higher (abt. 72%)
● Premature around 20-24 weeks = 42% show neurodevelopmental impairment & 19% show
sensory deficits around 18-22m of age
,Environmental Factors & Prenatal Development
Nutrition
● Foetus needs essential nutrients to grow + maternal malnutrition increases the risk of birth
complications & neurological deficits
● Malnutrition is difficult to study due to other risk factors like poverty, drug abuse, limited
access to health care, etc.
● A balanced diet is essential, including all essential vitamins + minerals
Stress & Emotion
● Emotions in response to stressful events DO impact prenatal development
○ Elevated prenatal stress = associated w. Increased stillbirths, impaired immune
response, heightened vulnerability to infectious diseases, slowed motor development
+ below average cognitive development
● The emotional reactions disrupt the hormonal balance of the mother
Drug Use
● Most drugs consumed by pregnant women slip through membranes of placenta
○ Basically all recreational drugs = harmful, esp. Sedatives, narcotics, cocaine + meth
● Babies can be born addicted to these drugs with increasing stats (already high, 21k n US per
year)
● Over-the-counter medication = also bad. Tobacco can be problematic as smoking increases
risk of miscarrying, sudden infant mortality, premature labour & stillbirths
● Longer term maternal smoking linked to poor self-regulation, deficits in academic
achievement + increased risk for psychological disorders
● Difficult to determine root causes due to other risky behaviours + genetic predispositions
Alcohol Consumption
● Heavy drinking can be hazardous to the foetus
● Foetal alcohol syndrome = collection of congenital (inborn) problems associated with
excessive alcohol use during pregnancy
● Problems include: microcephaly (small head), heart defects, hyperactivity, delayed motor
development + impaired cognitive development with academic difficulties
● Moderate drinking in pregnancy can have substantial negative effects
○ Increased risk for deficits in IQ, motor skills, attention span, impulsivity, antisocial +
delinquent behaviour
Maternal Illness
● This may be caused by infectious agents entering through the placenta (rare)
○ Measles, rubella, syphilis & chickenpox
● Amt. of damage depends on when mother contracts illness
● HIV causing AIDS can be transmitted from mother to offspring & AIDS prenatally through
the placenta during delivery, placenta or breastfeeding
● Antiviral drugs + cautious obstetrical care reduced transmission rates in modern world
, Environmental Toxins
● There are many environmental toxins that may affect prenatal development
● E.g. air pollution has been linked to cognitive development at 5yrs + increased obesity at 7yrs
+ social competence deficits in middle childhood
● Exposure to phthalate chemicals for household products relates w. IQ deficits of 6-7pts at 7yrs
Foetal Origins of Adult Disease
● Mothers’ experience to adverse events in pregnancy may cause easier susceptibility to
illnesses after birth
○ E.g. prenatal malnutrition = linked to schizophrenia, emerging in late adolescence &
early adulthood
○ E.g. low birth weight linked to increased risk of heart disease in later adulthood
● Prenatal development could also cause risk of depression, bipolar disorders, obesity, diabetes
+ some cancers
○ Genetic vulnerabilities may cause this + stress may cause genetics passed to offspring
Motor, Social & Language Development in Childhood
Motor Development
● Def - progression of muscular coordination required for physical activities
○ Basic motor skills= grasping, reaching, manipulating objects, sitting up, crawling,
walking + running
● Walking was mainly focused on + experience mastered with short walking bursts including
falls and may walk 14k steps per day which improves walking skills
● Early motor development depends mostly on physical growth + very uneven, sudden bursts
○ Growth spurts usually accompany w. Restlessness, irritability + increased sleep
○ Early skills has been attributed mostly to maturation
■ maturation = development that reflects the gradual unfolding of one’s genetic
blueprint, genetically programmed with age rather than experience = learning
○ New research: infants = active agents, not passive organisms waiting for limbs +
brain to mature. Ongoing exploration is the force behind development at infant level
Understanding Developmental Norms
● Developmental norms indicate the typical (median) age that individuals display various
behaviours and abilities
○ They’re benchmarks and shouldn’t be measured exactly to the day
● These norms should be looked at as group averages + variations are normal
○ The averages show at which age the child should exhibit 25%, 50%, etc motor skills
○ A large portion of kids don’t achieve these norms until long past the average norm
Cultural Variations & Their Significance
● Cross-cultural research shows the dynamic relationship btw experience + maturation in dev
● Rapid motor development has shown in certain cultures that provide special practice
○ E.g. Kipsigis people of Kenya teach their kids motor skills right after birth so
milestones are reached quicker (abt. a month earlier)
○ Slow development occurs in cultures that discourage motor exploration
