Psychology chapter 8 Development across the Life Span.docx

**Psychology chapter 8 Development across the Life Span** **Summary of Human Development Research** **Human Development**: This field studies changes in individuals from conception to death, examining aspects such as personality, cognition, and social interactions over the lifespan. **Research De...

**Psychology chapter 8 Development across the Life Span** **Summary of Human Development Research** **Human Development**: This field studies changes in individuals from conception to death, examining aspects such as personality, cognition, and social interactions over the lifespan. **Research Designs**: 1. **Longitudinal Design**: Follows the same participants over time to observe changes as they age. 2. **Cross-Sectional Design**: Compares different age groups at a single point in time, providing a snapshot of age-related differences. 3. **Cross-Sequential Design**: Combines longitudinal and cross-sectional methods, studying various age groups over time to track both differences and changes. **Cohort Effect**: This phenomenon occurs when a group shares a common experience or time period, impacting developmental outcomes. **Nature vs. Nurture**: - **Nature**: Refers to hereditary influences on personality, growth, and social behavior. - **Nurture**: Encompasses environmental factors, such as parenting styles and socioeconomic status, that affect development. The interaction between nature and nurture is key to understanding human development, with most researchers agreeing that both genetics and environmental influences play significant roles. Behavioral genetics explores this interplay further through methods like family, twin, and adoption studies. The ongoing debate focuses on the relative contributions of genetic inheritance versus life experiences to traits like intelligence and behavior. **Summary of Basic Building Blocks of Development** **Genetics and Heredity**: Genetics is the study of heredity, focusing on how traits and disorders are transmitted through genes, which are segments of DNA. **Key Components**: - **DNA (Deoxyribonucleic Acid)**: The molecule that carries genetic information, structured as two long strands linked by chemical bases. - **Chromosomes**: Humans have 46 chromosomes in each cell (except for sperm and egg), arranged in 23 pairs---22 autosomes and 1 pair of sex chromosomes (XX for females, XY for males). **Gene Interaction**: - Genes can be **dominant** (expressed if present) or **recessive** (expressed only when paired with another recessive gene). For example, brown hair is often dominant over blond hair. - Many traits are influenced by multiple genes, known as **polygenic inheritance**. **Genetic Disorders**: - **Dominant Disorders**: Only one parent needs to pass on the gene for the disorder to be inherited (e.g., Huntington\'s disease). - **Recessive Disorders**: These require both parents to pass on the gene (e.g., cystic fibrosis, sickle-cell anemia, PKU). **Chromosome Disorders**: - **Down Syndrome**: Caused by an extra chromosome 21, leading to intellectual disabilities and physical characteristics like almond-shaped eyes. - Other chromosome disorders include **Klinefelter syndrome** (XXY) and **Turner syndrome** (missing an X chromosome), affecting physical and reproductive traits. Overall, genetics plays a crucial role in human development by influencing traits and the inheritance of various disorders through complex interactions of DNA, genes, and chromosomes. **Summary of Prenatal Development (Sections 8.4--8.5)** **8.4 Fertilization** - **Fertilization Process**: When an ovum (egg) and sperm unite, they form a zygote, which has 46 chromosomes. The zygote divides through mitosis, eventually developing into a baby. - **Types of Twins**: - **Monozygotic Twins**: Identical twins formed from one fertilized egg that splits into two. - **Dizygotic Twins**: Fraternal twins that arise when two separate eggs are fertilized by different sperm. - **Multiple Pregnancies**: These can be high-risk and may lead to complications like premature birth. Bioethical concerns arise around selective termination for the health of remaining infants. **8.5 Three Stages of Development** - **Stages of Pregnancy**: 1. **Germinal Period** (first 2 weeks): After fertilization, the zygote moves to the uterus and implants itself. The placenta and umbilical cord begin to form. 2. **Embryonic Period** (2 to 8 weeks): The organism is now an embryo, and major organs and structures develop. This stage is critical, as exposure to teratogens (harmful substances) can lead to birth defects. 3. **Fetal Period** (8 weeks to birth): This period is characterized by rapid growth and maturation of organs. The fetus increases significantly in size and weight. - **Critical Periods**: Specific times when environmental influences can adversely affect development, particularly for different organs. For example, teratogens like alcohol can lead to fetal alcohol spectrum disorders (FASDs), causing physical and mental disabilities. - **Miscarriage**: Most common in the first trimester, often due to genetic defects. Overall, the prenatal development process is intricate, involving critical periods where environmental factors can significantly impact the developing fetus, emphasizing the importance of maternal health during pregnancy. **Summary of Infancy and Childhood Development (Sections 8.6--8.8)** **8.6 Physical Development** - **Infant Growth**: After birth, infants undergo rapid physical and sensory development. Key systems, such as respiratory and digestive, adjust to life outside the womb. Infants may lose some weight initially due to adapting to feeding. - **Motor Skills**: Significant milestones occur from birth to age 2, including: - Raising head and chest (2-4 months) - Rolling over (2-5 months) - Sitting up (4-7 months) - Crawling (7-8 months) - Walking (8-18 months) - **Brain Development**: At birth, the brain has over 100 billion neurons, which grow rapidly and undergo synaptic pruning to enhance functionality. **8.7 Sensory Development** - **Touch and Smell**: The sense of touch is well-developed at birth, and infants can differentiate their mother\'s milk scent from others shortly after birth. - **Taste**: Infants prefer sweet tastes at birth and develop a preference for salty flavors by four months. - **Hearing**: Newborns can hear but need time for full auditory development; they respond best to high-pitched sounds. - **Vision**: Vision is the least developed sense at birth, with poor color perception and visual acuity. Newborns see best at a distance of 7-10 inches, and their visual preferences lean towards complex patterns and human faces. **8.8 Cognitive Development** - **Early Cognitive Abilities**: Infants exhibit learning through reflexes and can recognize and react to changes in stimuli. Methods like preferential looking and habituation are used to study their cognitive capabilities. Overall, infancy is marked by crucial physical, sensory, and cognitive development stages that lay the foundation for future growth and learning. **Summary of Cognitive Development and Theories** **Cognitive Development Overview** By age 1, infants have tripled their birth weight and significantly increased their brain size, which supports rapid cognitive development, including advances in thinking, problem-solving, and memory. **Piaget\'s Theory of Cognitive Development** Jean Piaget proposed four stages of cognitive development: 1. **Sensorimotor Stage (Birth to 2 years)**: Infants learn through sensory and motor interactions. Key development includes object permanence. 2. **Preoperational Stage (2 to 7 years)**: Children develop language and symbolic thought but struggle with logical reasoning. They exhibit egocentrism, animism, and centration, leading to difficulties with conservation. 3. **Concrete Operations Stage (7 to 12 years)**: Logical thinking develops, allowing for conservation and reversibility, though abstract thinking is still challenging. 4. **Formal Operations Stage (12 years to adulthood)**: Abstract and hypothetical reasoning emerges. Not all individuals reach this stage. While Piaget emphasized stages, critiques suggest cognitive development is more continuous and that younger children might have more cognitive abilities than he recognized. **Vygotsky\'s Theory of Cognitive Development** Lev Vygotsky emphasized social interactions and cultural context in cognitive development. Key concepts include: - **Scaffolding**: Support from more skilled individuals helps learners gradually gain independence. - **Zone of Proximal Development (ZPD)**: The gap between what a child can do alone and with help. Vygotsky viewed private speech as a tool for cognitive advancement, contrasting Piaget's interpretation of it as egocentric. **Autism Spectrum Disorder (ASD)** ASD is a neurodevelopmental disorder characterized by challenges in social skills, communication, and cognitive processing. A critical aspect of autism is the lack of \"theory of mind,\" which hinders understanding others\' perspectives. Research suggests a mix of genetic, environmental, and neurobiological factors contribute to ASD. Misinformation, particularly linking autism to vaccines, stems from a discredited study and has led to public health issues, despite extensive evidence disproving this connection. **Summary of 8.8 Psychosocial Development** The psychological and social development of infants and children encompasses personality, relationships, and self-concept, beginning in infancy and extending into adulthood. **Temperament** Temperament refers to inherent behavioral and emotional characteristics identifiable at birth. Chess and Thomas identified three main types: 1. **Easy**: Regular in routines, adaptable, and generally happy. 2. **Difficult**: Irregular in schedules, resistant to change, and often unhappy. 3. **Slow to Warm Up**: Relatively regular but slow to adapt to new situations. Most infants display a mix of these styles, which are influenced by both genetics and environmental factors. **Attachment** Attachment is the emotional bond between an infant and their primary caregiver, typically forming within the first six months. This bond manifests through behaviors like stranger and separation anxiety. Mary Ainsworth\'s \"Strange Situation\" identified four attachment styles: 1. **Secure**: Infants explore while keeping an eye on their mother; they become upset when she leaves but are easily comforted upon her return. 2. **Avoidant**: Infants explore but show little interest in the mother's presence or absence. 3. **Ambivalent**: Infants are clingy, resistant to exploring, and display mixed reactions upon the mother's return. 4. **Disorganized-Disoriented**: Infants display confused behavior, showing fear or dazed expressions. These styles are influenced by the caregiver\'s responsiveness, with secure attachment linked to sensitive caregiving. **Self-Concept** Self-concept develops as infants differentiate themselves from their surroundings. The \"rouge test\" illustrates this: infants typically recognize themselves in a mirror by around 15-18 months, marking the start of self-awareness, which evolves to include gender, physical traits, and personality attributes. **Erikson\'s Theory** Erik Erikson proposed eight stages of psychosocial development, emphasizing the importance of social relationships. The first four stages occur during infancy and childhood, focusing on crises that must be successfully resolved for healthy psychological development. For example, the first stage centers on trust versus mistrust, influenced by caregivers\' responsiveness to infants\' needs. **Classic Studies** Harry Harlow\'s studies with rhesus monkeys highlighted the importance of \"contact comfort\" over mere feeding in attachment formation, showing that emotional needs significantly influence attachment behavior. Overall, understanding temperament, attachment, and self-concept is crucial for recognizing how early experiences shape personality and relationships throughout life. **Summary of Adolescence** **Herd Immunity**\ Herd immunity occurs when a significant portion of a population is immune to a disease, typically through vaccination. This immunity helps protect individuals who are not immune by reducing the disease\'s spread. An example is \"Typhoid Mary,\" who unknowingly spread typhoid fever due to a lack of herd immunity in her community. **Adolescence Overview**\ Adolescence is the developmental stage from approximately ages 13 to early 20s, characterized by physical, cognitive, and psychosocial changes. It is marked by the onset of puberty, which involves significant physical development and the maturation of sex characteristics. Adolescents are often not yet fully independent adults, and the duration of adolescence varies by individual. **Physical Development**\ Puberty is the key marker of adolescence, involving hormonal changes that lead to physical growth and the development of primary and secondary sex characteristics. Brain development continues into the early 20s, particularly the prefrontal cortex, which is crucial for decision-making and impulse control. This incomplete development can lead to risk-taking behaviors common in adolescents. **Cognitive Development**\ Cognitive growth includes advances in abstract thinking, as proposed by Piaget's formal operations stage. Adolescents begin to think hypothetically and develop moral reasoning. However, they often experience egocentrism, believing in their uniqueness (personal fable) and assuming others are constantly aware of them (imaginary audience). **Moral Development**\ Kohlberg\'s theory outlines three levels of moral reasoning: 1. **Preconventional** - Morality based on consequences. 2. **Conventional** - Morality based on societal rules. 3. **Postconventional** - Morality based on personal judgment.\ Critiques of Kohlberg\'s theory highlight potential biases, particularly regarding gender differences in moral perspectives, as proposed by Carol Gilligan. **Psychosocial Development**\ Erikson\'s stage of identity versus role confusion describes the adolescent\'s quest for a stable sense of self. Successful navigation of this stage leads to resilience against peer pressure, while unresolved conflicts may result in confusion and dependence. Parent-teen conflicts are common and often revolve around trivial matters, though deeper moral agreements typically exist. This period is crucial for forming personal identity, impacting relationships and choices, including susceptibility to peer pressure and the pursuit of independence. **Summary: Adulthood and Aging (Sections 8.12--8.17)** **Defining Adulthood:** Adulthood spans from the early 20s to old age, but its exact start varies across cultures. Some consider it to begin after puberty, high school graduation, or even after college. Many developmental psychologists refer to \"emerging adulthood\" as the phase from late adolescence through the 20s, marked by childlessness, instability in living arrangements, and dependency on parents. **Physical Development:** Adulthood includes young adulthood, middle age, and late adulthood, with physical changes being gradual. Young adulthood (20s) is typically a peak health period, although aging signs begin to emerge, like wrinkles and declining senses by the 30s and 40s. Middle age sees further physical declines, such as weight gain, height loss, and hormonal changes (menopause for women, and andropause for men). Health issues like high blood pressure and heart disease often arise during this period. **Cognitive Development:** Cognitive abilities, particularly memory, change with age. While processing speed may decline in middle age, life experience compensates for this. Memory retrieval can become challenging due to stress and the accumulation of information. Engaging in mentally stimulating activities helps maintain cognitive health. **Psychosocial Development:** Erikson's stages highlight key psychosocial tasks in adulthood. Young adults grapple with intimacy versus isolation, seeking deep connections while maintaining individuality. Middle adults focus on generativity versus stagnation, aiming to contribute to the next generation. Effective parenting styles include authoritative (balanced approach), authoritarian (rigid), and permissive (lax), with authoritative generally yielding the best outcomes for children. **Theories of Aging:** Four theories explain aging: the cellular-clock theory (limited cell reproduction), wear-and-tear theory (damage from stress and use), free-radical theory (cellular damage from unstable molecules), and activity theory (positive adjustment through active engagement). **Stages of Death and Dying:** Kübler-Ross outlines five stages of response to death: denial, anger, bargaining, depression, and acceptance. Cultural practices surrounding death, such as family involvement in Hindu traditions, influence the dying process and mourning practices. **Conclusion** Adulthood and aging encompass complex physical, cognitive, and psychosocial changes influenced by individual experiences, cultural contexts, and biological factors. Understanding these stages helps navigate the transitions of adulthood and the inevitability of aging.