Mental & Physical Development over Lifespan

• 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.

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
• 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
  • 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
• 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
• 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
  • 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
  • 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

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

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
• 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