- Developmental psychology examines changes in biological, physical, psychological, and behavioural processes over age
- Four issues guide developmental research:
- Nature and nurture – To what extent is our development the product of heredity (nature) or the product of the environment (nurture)? How do they interact?
- Critical and sensitive periods – Are some experiences especially important at particular ages?
- Critical period – an age range during which certain experiences must occur for normal development
- Sensitive period – an optimal age range for certain experiences, but no critical range
- Continuity versus discontinuity – Is development continuous and gradual, like the growth of a tree? Or is it discontinuous, progressing through qualitatively distinct stages, such as a caterpillar to a butterfly.
- Stability versus change – Do our characteristics remain consistent as we age?
- Five developmental functions:
- No change – an ability from birth remains constant over life span
- Continuous – an ability that develops gradually and then remains constant
- Discontinuity – an ability that progresses in stages (crawling, standing, walking)
- Inverted U-shaped function – an ability that peaks at a certain age, then decreases (Divorce anxiety)
- U-shaped function – an ability that is present early in life, disappears temporarily, and re-emerges later.
- Different designs used to research:
- Cross-sectional design – research design that compares people of different age groups at same point in time. Perform the acuity test once.
- Drawback in that different age groups (cohorts) grew up in different periods
- Longitudinal design – repeatedly tests same cohort as it grows older. (Ex. Test 10 year olds continuously for 10 year intervals until they are 60)
- Sequential design – combines the cross-sectional and longitudinal designs, repeatedly testing several age cohorts as they grow older to determine whether they follow a similar developmental pattern.
- Cross-sectional design – research design that compares people of different age groups at same point in time. Perform the acuity test once.
Prenatal Development
- Consists of three stages:
- Germinal stage – first two weeks, zygote (fertilized egg) is formed
- Embryonic stage – second to eighth week, zygote becomes embryo (placenta and umbilical cord form, organs form)
- Fetal stage – after nine weeks, embryo becomes fetus (bodily systems develop, eyes open at 24 weeks, attains age of viability at 28 weeks)
- Y chromosome contains TDF (testis-determining factor) gene which initiates development of testes at around 6-8 weeks
- Various environmental influences can affect development
- Teratogens – environmental agents that cause abnormal development
Infancy and Childhood
- The Amazing Newborn
- Newborn sensation and perception
- Vision is limited by poor acuity, lack of coordinated eye movements, and tunnel vision
- Newborns orient to significant stimuli
- Prefer patterned and more complex images
- Newborn learning
- After repeated exposure to certain sound, infants begin to stop turning to see source of sound, but would turn towards new sound
- Rapidly acquire classically conditioned responses
- Newborn sensation and perception
- Sensory-Perceptual Development
- Visual field expands to almost adult size by six months, acuity continues to develop afterwards
- Sound localization disappears in second month of life, returns after four or five months
- Physical, Motor, and Brain Development
- Maturation – genetically programmed biological process that governs growth
- Physical and motor development follows principles
- Cephalocaudal principle – reflects tendency for development to proceed in head-to-foot direction
- Proximodistal principle – states that development begins along innermost parts of body and continues outward
- Brain matures from inner parts (that govern basic survival functions) to cortex
- Reflexes – automatic, inborn behaviours elicited by specific stimuli
- Physical and motor development are also influenced by experience and environment
- Regularly massaged infants gain weight more rapidly and show fast neurological development
- Visual deprivation can damage visual abilities
- Cognitive Development
- Piaget believed that development results from maturation and experience, and that thinking changes qualitatively with age
- Brain builds schemas (organized patterns of thought)
- Two processes involved in acquiring new schemas
- Assimilation – process by which new experiences are incorporated into existing schemas (child who sees a horse for first time may call it a “big dog”)
- Accommodation – process by which new experiences cause existing schemas to change (child will realize the “big dog” isn’t a dog)
- Four major stages of cognitive growth:
- Sensorimotor stage (Birth to 2) – children understand their world primarily through sensory experience and physical interaction
- Around eighteen months, achieve object permanence (ability to understand that an object continues to exist even out of sight)
- Pseudoimitation (child can imitate actions just produced) present
- Preoperational stage (2-7) – children represent the world symbolically through words and mental images, but do not understand basic mental operations
- Cannot understand concept of conservation (principle that basic properties of objects, such as mass and volume, stay the same despite change in outward appearance)
- Exhibit egocentrism (difficulty in viewing world from someone else’s perspective – children believe that others perceive world as they do)
- Concrete operational stage (7-12) – children can perform basic mental operations concerning problems that involved concrete objects and situations
- Formal operational stage (12+) – children are able to think logically and systematically about concrete and abstract problems
- Sensorimotor stage (Birth to 2) – children understand their world primarily through sensory experience and physical interaction
- Universal tests show that the general cognitive abilities associated with the four stages appear to occur in the same order across cultures (Piaget is only a partial dumbass)
- Culture has been found to influence cognitive development
- Cognitive development within each stage seems to proceed inconsistently
- Zone of proximal development – the difference between what a child can do independently and what the child can do with assistance from adults (social interaction affects development)
- Cognitive development is best examined within information processing framework
- Processing speed improves during childhood
- Memory capabilities expand significantly
- Younger children lack metacognition (awareness of one’s own cognitive processes)
- Theory of mind – a person’s beliefs about the mind and the ability to understand other people’s mental states
- Piaget believed that development results from maturation and experience, and that thinking changes qualitatively with age
- Moral Development
- Lawrence Kohlberg developed a stage model of cognitive development:
- Preconventional stage – moral judgments are based on anticipated punishments or rewards
- Conventional stage – moral judgments are based on conformity to social expectations, laws, and duties
- Postconventional stage – moral judgments are based on well though out, general moral principles
- Researchers have studied moral reasoning throughout all cultures
- Moral reasoning changes from preconventional to conventional
- Postconventional reasoning is relatively uncommon
- Stages cannot be skipped
- Postconventional reasoning occurs more often among Western culture, though this can be attributed to different moral values
- Lawrence Kohlberg developed a stage model of cognitive development:
- Personality and Social Development
- Erik Erikson believed that personality develops through confronting a series of eight major psychosocial stages (each of which involves a different conflict over how we view ourselves in relation to others)
- Four crises that occur in infancy and childhood:
- Basic trust versus basic mistrust
- Autonomy versus shame and doubt
- Initiative versus guilt
- Industry versus inferiority
- Four crises that occur in infancy and childhood:
- Attachment – the strong emotional bond that develops between children and caregivers
- Imprinting – sudden, biologically primed form of attachment
- Freud’s Cupboard Theory – attachment to caregiver is side-effect of ability to provide basic satisfaction (food)
- Harry Harlow found that contact comfort is more important that the provision of nourishment
- John Bowlby proposed that attachment develops in three phases:
- Indiscriminate – newborn behaviours evoke caregiving from adults
- Discriminate – infants direct attachment to ore familiar caregivers
- Specific – infants develop meaningful attachment to specific people
- Stranger anxiety – distress over contact with unfamiliar people
- Separation anxiety – distress over being separated from a primary caregiver
- Strange Situation Test – test for examining infant attachment
- Anxious resistant infants are fearful with mother present, demand attention, and are distressed when she leaves
- Anxious avoidant infants show few signs of attachment and seldom cry without mother
- Most infants found to be securely attached (enjoy presence of mother)
- Different types of attachment deprivation can affect infants in several ways
- Isolated children and monkeys did not develop properly
- Infancy is a sensitive period in which initial attachment to caregivers forms most easily and facilitates development
- Daycare affects children’s development in various ways
- Does not disrupt attachment to parents
- Infants in daycare are slightly less engaged and sociable towards mothers
- Infants from low income families with high quality daycare are better socially adjusted
- Different styles of parenting can also affect children’s development
- Authoritative – controlling, but warm, and establish and enforce clear rules within a caring, supportive atmosphere
- Children: higher self esteem, higher achievers, fewer conduct problems, more considerate
- Authoritarian – exert control over children, but do so with a cold, unresponsive, or rejecting relationship
- Children: lower self-esteem, less popular, perform poorly in school
- Indulgent – warm and caring, but do not provide guidance and discipline
- Children: immature and self-centred
- Neglectful – provide neither warmth, nor rules, nor guidance
- Children: insecurely attached, low achievement motivation, disturbed relationships, impulsive, and aggressive
- Authoritative – controlling, but warm, and establish and enforce clear rules within a caring, supportive atmosphere
- Parents play role in helping children develop gender identity
- Gender identity – sense of “maleness” or “femaleness”
- Gender constancy – understanding that being of a gender is permanent (develops around age six to seven)
- Socialization – the process by which we acquire beliefs, values, and behaviours of a group
- Plays key role in shaping gender identity and sex-role stereotypes
- Erik Erikson believed that personality develops through confronting a series of eight major psychosocial stages (each of which involves a different conflict over how we view ourselves in relation to others)
Adolescence
- Physical Development
- Puberty – period of rapid maturation in which the person becomes capable of sexual reproduction
- Early maturation tends to have more positive outcomes for boys than girls
- Boys acquire strength and size
- Girls more likely to develop eating disorders, smoke, drink, and have problems academically
- Cognitive Development
- Capacity for abstract reasoning increases substantially during adolescence
- Adolescent egocentrism – highly self-focused thinking
- Adolescents overestimate the uniqueness of their feelings and experiences
- Always feel that they are “on stage” and being watched and judged
- Social and Personality Development
- Erik Erikson interviewed many adolescents to understand sense of identity
- Many had identity diffusion (had not yet gone through identity crisis, and remain uncommitted to a coherent set of values)
- Others found to be in foreclosure (adopted an identity without going through a crisis)
- Moratorium – adolescents experiencing a crisis, but have not yet resolved
- Identity achievement – adolescents who have gone though a crisis and successfully resolved it
- Most adolescents report getting along “well” and “fairly well” with parents
- Adolescents often agree with parents’ right to make rules, but not with some issues
- Girls believed to be granted autonomy at a later age than boys
- Erik Erikson interviewed many adolescents to understand sense of identity
Adulthood
- Physical Development
- Physical functioning peaks in young adulthood, and declines at mid-life
- Cognitive Development
- Several theorists propose a fifth stage of cognitive development
- Post-formal thought – people can reason logically about opposing points of view and accept contradictions and irreconcilable differences
- Information processing and memory change into adulthood
- Perceptual speed (reaction time) declines steadily
- Memory for new factual information, spatial memory, and memory recall decline
- Fluid intelligence declines earlier than crystallized intelligence
- Regular exercise and perceptual-motor activities may preserve cognitive abilities
- Wisdom scores found to rise from age 13 to 25, and then remain stable
- Several theorists propose a fifth stage of cognitive development
- Social and Personality Development
- Social clock – a set of cultural norms concerning optimal age range for work, marriage, parenthood, and other major life experiences
- Erik Erikson proposed different stages and critical events
- Intimacy versus isolation (20-40)
- Generativity versus stagnation (40-60) – how generous a person becomes
- Integrity versus despair (60+) – a sense of completeness and fulfillment
- People who live together prior to marriage are at higher risk of divorce
- Not causal, most likely due to lack of religiousness, less commitment to marriage
- U-shaped relation found in marital satisfaction
- Happiness greatest before children, drops during children, rises again after children leave home
- Various stages affect the establishment of a career
- Growth stage (childhood to mid-twenties) – form initial impressions about types of jobs we like and dislike
- Exploration stage (immediately after) – form tentative ideas about a preferred career and pursue necessary training
- Establishment stage (mid-twenties to mid-forties) – begin to understand whether they made correct choice
- Maintenance stage (end of establishment) – become more satisfied with choice
- Decline stage – investment in work decreases, followed by retirement
- Little evidence that most people experience mid-life crisis
- Elisabeth Kubler-Russ found five stages that terminally ill patients experience as they cope with death
- Denial, anger, bargaining for life, depression, acceptance
