>> Discovering Psychology by Don Hockenbury, Sandra E Hockenbury (6th Edition)


Chapter 9: Lifespan Development


  1. The Description of Genotype and Phenotype
    • Development psychology- determines the changes made by people throughout the lifespan
    • Zygote- is a single cell where life began
    • Chromosomes- a chemical structure where inherited genetic information is encoded
      1. Genes- the DNA segments found in every chromosome. It controls the production of proteins
    • Genotype- the genetic framework of an organism
      1. Alleles- different forms of a specific gene
    • Phenotype- pertains to the features that an organism realistically demonstrates
      1. Gene expression is influenced by environmental factors
      2. Different genotypes display various reactions to environmental factors
      3. Epigenetics- identifies the factors that moderate gene expression
      4. The interaction of multiple genes is the most involved feature

  2. The Prenatal Stage
    • Germinal period- signifies the first 2 weeks of prenatal stage
      1. The zygote  splits and forms into a multicellular embryo
    • Embryonic period- starts at the 3rd week to 8th week of pregnancy
      1. Main body systems are formed
      2. This the stage where vulnerability to teratogens, birth defect causing substances, is high.
      3. Fetal alcohol syndrome- caused by overdrinking
    • Following 3 weeks from conception, the human brain develops into a neural tube where stem cells are lined. The development of brain follows this sequence: hindbrain, midbrain, and forebrain.
    • Fetal period- starts from 9th week to birth
      1. The mother feels the movement of the fetus, or quickening, in the 4th month
      2. The baby’s weight doubles during the final 2 months of pregnancy.

  3. The Developments After Birth
    • infant reflexes:
      1. Rooting reflex- incited by a touch on the cheek
      2. Sucking reflex- triggered by a touch to the lips
      3. Grasping reflex- incited by placing a finger to both palms
    • Patterns of physical development:
      1. Cephalocaudal pattern- held the proposition that physical and motor skills develop from top to bottom.
      2. Proximodistal trend- the inclination of newborns to mature motor control of their bodies from center to outwards.
    • Temperament- consistent innate tendencies of infants to behave and respond in a specific way.
      1. Alexander Thomas and Stella Chess- introduced the classifications of temperamental patterns of babies:
        1. Easy- demonstrate positive temper
        2. Difficult- irritable and emotional
        3. Slow-to-warm-up- embrace novel experiences gradually
      2. Jerome Kagan- categorized temperament in regards to reactivity
        1. High-reactive- intense responsiveness to new experiences and strangers
        2. Low-reactive- calmer and  courageous
      3. Temperament is also influenced by genetic and environmental elements
      4. Attachment- the emotional link between the babies and their caregivers
        1. Mary D. Salter Ainsworth- created a measurement of attachment, known as the Strange Situation process.
    • Language development:
      1. Infant-directed speech- an easy vocabulary and expression used by adults to communicate to infants.
      2. Babies starts to coo at around 3 months of age and babbles at about 9 months of age.
      3. The one-word stage manifests the truth that babies have larger comprehension vocabulary than production vocabulary.
      4. In the two-word stage, babies use two words to form a sentence.
    • Gender roles- are the characteristics and behaviors that are assigned by culture as either masculine or feminine
      1. Between the age of 18 months to 2 years old, behavior in regards to sex differences starts. Children between 2-3 years old begin possessing gender-role standards for wardrobe, games, and toys.
      2. Theories that elaborate about gender roles
        1. Social learning theory- held that proper behaviors for every gender can be learned through reinforcement, modeling, and penalty
        2. Gender schema theory- held that gender-role development is impacted by the creation of schemas, or mental significations of genders.
    • Piaget’s theory- authored by Jean Piaget which held that children develop through 4 cognitive stages
      1. Sensorimotor stage- occurs until 2 years of age. Infants learn through direct experiences.
      2. Preoperational stage- occurs between 2-7 years old. Children learn to use symbolic thought, the capacity to use images and words to signify the world. Thinking is displayed and characterized by
        1. Egocentrism- failure to see events from another perspective
        2. Irreversibility- inability to reverse a series of events
        3. Centration- inclination to concentrate on a single aspect of an event
      3. Concrete operational stage- at this stage, children are able to create real logical thought
      4. Formal operational stage- children are able to formulate logical thinking in the presence of abstract principles.
    • Renee Baillargeon- used visual tasks as basis on his research of object permanence.
    • Lev Vygotsky- emphasized the role of social and cultural factors in developing the cognitive functions.
      1. Zone of proximal development- held that children can achieve higher cognitive levels through the aid of highly competent people.

  4. The Puberty Stage
    • Adolescence- marks the children’s passage to adulthood
    • In puberty, the sexual maturity and reproductive capability starts. Its physical changes is classified as
      1. development of primary sex characteristics- refers to sex reproductive organs, like uterus for girls.
      2. Development of secondary sex characteristics- refers to signs of sexual maturity, such as height, voice modulation, and breast development.
    • Factors that impact the onset of puberty
      1. Genetics
        1. Females get their menarche at the same age with their mothers.
      2. Environmental factors
        1. Children experiences early puberty when they are healthy and lack the presence of a father at home
    • Females and males who mature early have high risk of drug and alcohol abuse.
    • During the adolescent period, peer influence is at its highest peak and romantic relationships become important.
    • Erik Erikson- conceived a theory of psychosocial development emphasizing that a specific psychosocial conflict signifies each life stage. Identity versus role confusion is related with puberty.
    • Lawrence Kohlberg- developed a theory of moral development, which held that children evolved from this following sequence: preconventional, conventional and postconventional moral reasoning. His theory is met by the following criticisms:
      1. Moral reasoning is not absolute in forecasting moral behavior. Instead, moral decisions are influenced by nonrational elements, like emotional reactions.
      2. Carol Gilligan questioned the universality of the results. She asserts that both genders have different moral reasoning.
      3. Personal rights are emphasized in this theory which doesn’t apply to cultures that value interdependence.

  5. The Physical Changes and Social Relationships in Emerging Adulthood
    • Emerging adulthood- the stage between late teens and late 20s.
      1. In industrialized cultures, this stage is described by exploration, uncertainty, and versatility in social functions, relations, and job opportunities.
    • Physical changes
      1. Genetic changes vary from each person
      2. Wrinkles start to show at the age of 40
      3. Physical strength slowly deteriorates
      4. Women experience menopause, the end of menstruation signals while men experience a slow drop in testosterone levels
    • Adult relationships are diverse and reflects that it doesn’t observe a pattern.
      1. The birth of the first offspring tends to diminish the satisfaction and time spent among couples.
      2. Parenthood changes the characteristics of an adult.
      3. Marital satisfaction is restored when children move out.

  6. The Cognitive Changes and Social Development in Late Adulthood
    • Mental capacity remains stable until 60 years old. After that, common intellectual abilities, such as word memory, logical reasoning, and math competencies, slightly deteriorates.
      1. These negative effects can be reduced by engaging in physical and mental tasks.
    • Activity theory of aging- held that life satisfaction is achieved in late adulthood when individuals keep their past levels of activity.
    • Ego integrity- is another prescription for sound mental well-being which means the feeling of a meaningful life.

  7. The Stages of Dying
    • Elisabeth Kubler-Ross- suggested the 5 stages undergone by the dying
      1. Denial
      2. Anger
      3. Bargaining
      4. Depression
      5. Acceptance
    • People react in various ways to impending death.