Chapter 11: Human development across the life span
Study of human development: Transition & Continuity
Parents constantly talk about their children. This reflects their level of engagement which effects level
of attachment. (Mary Ainsworth)-> They are also amazed of changes as their children grow.
Ex: Emily carr asked young child to describe creative art. “I think, and then I draw a line round my
think.” Children grasp things differently more quickly and adequately than adults.
Development: Is the sequence of age-related changes that occur as a person progresses from
conception to death. (Cumulative process that includes both biological and behaviour changes)
1. Prenatal period (between conception and birth-9 months)
Progress before birth: Prenatal Development
Conception occurs when fertilization= Zygote: a one celled organism formed by the union of a sperm
and an egg. Chromosomes passed on by parents found in nucleus, containing genes.
Prenatal Development -remarkably rapid
1. Germinal stage: first phase, first 2 weeks after conception.
36 hours- rapid cell division begins and the zygote becomes a microscopic mass of multiplying cells.
• Cells migrate along mother’s fallopian tube to uterine cavity.
• 7 day, cell implants itself in the uterine wall. Many zygotes are rejected at this point.*1 in 5
pregnancies end with the women being unaware of conception.
• Placenta is a structure that allows oxygen and nutrients to pass into the fetus from the
mother’s bloodstream -> formed during the implantation process.
2. Embryonic stage: lasts from 2 weeks-2 month.
• Vital organs begin to form= Embryo( developing organism)
• Very vulnerable, all basic physiological structures are being formed. (miscarriage, birth defects)
3.Fetal Stage: from 2 months-birth
• Muscles, bones begin to form. Fetus becomes capable of physical movement.
• Sex organs begin to form during the third month.
• Last 3 months of this stage, brain cells multiply. • Layer of fat is deposited under skin for insulation.
• Between 22-26 weeks fetus reaches age of viability: age at which a baby can survive in the
event of a premature birth.
Teratogens are any external agents, such as drugs or viruses that can harm an embryo or fetus.
Maternal drug use tabacco, alcohol, prescriptional and recreational drugs.
Herion: increased risk of early death, birth defects, respitory difficulties.
Cocaine: birth complications, cognitive defects.
Marijuana: physical and cognitive defects, prefrontal part of brain at age 3. ( attention, problem
Fetal alcohol syndrome is a collection of congenital (inborn) problems associated with excessive
alcohol use during pregnancy.
Alcohol: small head( microcephaly), heart defects, hyperactivity, delayed mental and motor
Maternal illness and exposure to toxins, maternal nutrition and emotions, Fetal origins of Disease.
Margaret Norrie McCain & Fred Mustard- neuroscience and early childhood development, make
recommended conditions at home and school to promote success.
Motor development: refers to the progression of muscular coordination required for physical activity.
The cephalocaudal trend: the head-to-foot direction of motor development.
* Children tend to gain control over upper body before lower part.
Proximodistal trend: centre-outward direction of motor development.
*Children gain control of torso before extremities.
Maturation: is development that reflects the gradual unfolding of one’s genetic blueprint. (Genetically
programmed physical changes) motor skills through experimentation, but facilitated through
Developmental norms: indicate the median age at which individuals display various behaviours and
Early motor development depends on maturation. Later motor development is another matter
*without experience maturation cannot lead to new skills. Differences in temperament
Temperament: refers to characteristic mood, activity level and emotional reactivity.
Alexander Thomas & Stella Chess conducted major longitudinal study of development of
Longitudinal design: investigators observe one group of participants repeatedly over a period of
time. Often contrasted with the cross section approach.(different children tested at each checkpoint)
Cohort effects occur when differences between age groups are due to the groups growing up in
different time periods.
*longitudinal designs tend to be more sensitive to developmental changes. Downside takes long.
• Temperamental individuality is established by 2-3months old
Easy children- happy, regular sleeping, eating, adaptable, not readily upset. ( 40%)
Slow to warm up children: less cheery, less regular sleeping etc..(15%)
Difficult children: glum erratic in sleeping etc…(10%)
Remaining 35% showed mixture of these three temperaments. )genetic basis for temp
Jerome Kagan- 15-20% inhibited temperament (shyness, timid of unfamiliar people).*risk anxiety
25-30% uninhibited temperament (outgoing)
Attachment refers to the close, emotional bonds of affection that develop between infants and their
• Infants attachment to mother is not instantaneous, by 6-8 months show preference to mother.
Separation anxiety: emotional distress seen in many infants when they are separated from people
with whom they have formed an attachment. (
Peaks around 14-18 months and then begins to decline)
Theories of attachment
Initially agrued that mother becomes conditioned reinforce because they feed the infant.
Harry Harlow- Infant rhesus monkey
• Took monkeys from birth and raised them by 2 tyoes of “substitute mothers” : one made by
cloth to provide comfort, the other made by wires.
• Half monkeys were fed by cloth mother, half by wire mother. • Attachment was tested by introducing a frightening stimuli. Hypothesis that if attachment was
due to feeding monkey would run to the mother that fed them.
***monkey ran to cloth mother even if they were not fed by them.
John Bowbly- Biological basis for attachment, influenced by evolutionary theories
• Survival value for infants, attachment contributes to reproductive fitness.
• Parent-child attachment foster social and emotional development in children= genes passed
on to future generations.
Patterns of Attachment
Mary Ainsworth- suggests that attachment emerges from complex interplay between mother &
Strange situation procedure: Infants are exposed to a series of 8 separation and reunion episodes
to assess the quality of attachment.
• 3 min episode, stranger enters room where infant is playing, parents nearby, leaves returns,
leaves then returns child’s reaction carefully monitored to gauge attachment quality.
• Secure attachment: Play comfortably with mother present, upset when leaves, calm when
• Anxious-ambivalent attachment: Appear anxious with mother present, protest when she
leaves, but are not comforted when she returns.
• Avoidant attachment: Seek little contact with mother, not distressed when she leaves.
• Disorganized-disoriented attachment: Confused whether they should approach or avoid
mother, they are insecure.
*Attachment may depend on infant’s temperament and mothers sensitivity. ^sensitivity= secure
Sigmund Freud- personality laid down by age 5.
Erik Erikson- personality develops over time. (Both believed early childhood events have big
Stage: developmental period during which characteristic pattern of behaviour are exhibited and
certain capacities become established.
Stage theories assume:
1. Individuals must progress through specified stages in particular order because each stage
builds on previous stage. 2. Progress through these stages us strongly related to age
3. Development is marked by major discontinuities= dramatic transition in behaviour.
Erikson’s stage Theory
• 8 stages- personality shaped by how individuals deal with these psychosocial crises.
• Two opposing tendencies tug of war
Childhood stages( 4 stages)
• First year of life- Trust vs. Mistrust: Adult dependent, biological needs are met= optimistic,
trusting. Basic need not met= distrusting, pessimistic person.
• 2 & 3 years- Autonomy vs. Shame & doubt: Take some personal responsibility. If all goes
well= self-sufficient, if not= personal shame and doubt.
• 4-6 years- Initiative vs. Guilt: Initiative may conflict with parents= instil guilt= self-esteem
• 6-puberty—Industry vs. Inferiority: Learning to function socially, pride in accomplishment=
sense of competence.
Erikson’s theory- Strength: Transition & continuity
• Transition by showing how new challenges in social relationships stimulate personality
development through life.
• Continuity by connecting early childhood experiences to adult personality.
• Depends heavily on illustrative case studies= varied interpretations
• “Idealized” description of typical developmental patterns= can’t explain individual differences/
enormous personality differences among people.
The Growth of Thought: Cognitive Development
Cognitive development: transitions in youngsters’ patterns of thinking; reasoning, remembering,
• Rapid cognitive development himself
• Met Theodore Simon- collaborated with Alfred Binet= first useful intelligence test.
• Gave children intelligence tests, became interested in how children USE their intelligence.
Children progress in their thinking through: • Assimilation: interpreting new experiences in terms of existing mental structures without
• Accommodation involves changing existing mental structures to explain new experiences.
*EX: child learned to call four-legged pets “Dog”. First time child sees cat=Dog( Assimilation)will
later learn dogs & cats are different types of animals=make adjustment to mental scheme.
*age norms as approximation, but all children go through these stages in the same order.
1. Sensorimotor Period ( Birth-2yrs)- Infants develop ability to coordinate their sensory input
with motor actions. Development of object permanence.
Object permanence: child recognizes that objects continue to exist even when they are no longer
visible.(4-8month/fully 18months) * Hide toy= no longer exists, doesn’t attempt to search.
2. Preoperational Period (2-7yrs)- Improve their use of mental images, shortcomings in
*Filled identical beakers with same amount of water, then poured it into a thinner, taller beaker.
Children looked at the height of water= concluded that the beaker had more water. Did not master the
principle of conservation.
Conservation: Term for awareness that physical quantities remain constant constant, regardless of
shape or appearance.
Preoperational thinking= cannot understand conservation because”
• Centration: tendency to focus on just one feature of a problem neglecting other important
aspects.(ex: focus on height, not considering the width)
• Irreversibility: inability to envision reversing an action. (can’t mentally undo something)