Development pt.1 PDF

Monday, Jan 12, 2025 Environmental Influences on Intelligence The Flynn Effect: ◦ The steady increase in average IQ scores across generations. ◦ Likely influenced by improved education, health, and access to information. ‣ Example: Intelligence question evolution ("What do dogs a...

Monday, Jan 12, 2025 Environmental Influences on Intelligence The Flynn Effect: ◦ The steady increase in average IQ scores across generations. ◦ Likely influenced by improved education, health, and access to information. ‣ Example: Intelligence question evolution ("What do dogs and rabbits have in common?" promotes abstract reasoning). Science vs. Utilitarian Knowledge: ◦ Scientific reasoning emphasizes abstract and conceptual understanding. ◦ Practical knowledge focuses on direct, everyday applications. The Rubber Band Hypothesis: ◦ Intelligence is flexible, influenced by both genetic potential and environmental factors. ◦ Selective Breeding Studies: ‣ Tyron’s Study: Bred "bright" and "dull" rats for maze-solving abilities. ‣ Cooper and Zubec (1958): Demonstrated the importance of environment in mitigating genetic differences. Key Developmental Stages Developmental psychology: The study of changes over the life span of physiology, cognitive, emotion and social behavioural. Prenatal Period: From conception to birth. Infancy: Birth to 18-24 months; rapid growth and sensory development. Childhood: From infancy to 11-14 years; motor, cognitive, and social skills develop. Adolescence: Puberty to 18-21 years; identity formation and abstract reasoning emerge. Adulthood: Post-adolescence to death; cognitive changes and life transitions. Prenatal Development Gestation: The process of development in the womb, lasting approximately 40 weeks and divided into three stages: germinal, embryonic, and fetal. Germinal (Zygote) Stage (0-2 weeks) ◦ Begins with fertilization of the ovum ◦ Implants in the uterus ◦ After one week, about 100 cells in two layers ‣ Skin, hair, nervous system, and sense organs ‣ Digestive & respiratory systems, glands Embryonic Stage (2-8 weeks) ◦ Development speeds up. ‣ One month: Heartbeat, a tiny brain, body structures starting ‣ Two months: Major features are discernible (fingers, toes eyes) Most susceptible to chemicals causing birth defects. ‣ Sexual Development - Formation of gonads Female by default, the Y chromosome causes the development of testes, which produce testosterone, which brings about the development of male sex organs. Fetal Stage (2 months- Birth) ◦ Development of bone cells ◦ Further development of the skeletal, organ and nervous systems. ‣ After 2nd month: 4 cm length, 30 g. ‣ After 3rd month: 8 cm length, 90 g. Major organs are developed, kicking may begin ‣ After 4th month: 15 cm length, 170 g. Mother can feel movements, heartbeat can be heard, sleep/ waking ‣ After 6th month: 30 cm length, 700 g. ‣ Seventh month: Critical month, fetus may survive outside womb. ‣ Last two months: Gains about 250g per week. Prenatal Brain Development: ◦ Neural Tube Formation: ‣ Forms around 3 weeks after conception, developing into the brain  and spinal cord. ‣ Defects (e.g., spina bifida, anencephaly) can result from folic acid deficiency. ◦ Key Milestones: ‣ 4 Weeks: Forebrain, midbrain, hindbrain start to differentiate. ‣ 7 Weeks: Spinal cord supports limb movement. ‣ 11 Weeks: Development of cerebral hemispheres, cerebellum, brain stem. ‣ 7 Months: Cortical folding appears; myelination begins. ‣ Birth: The brain weighs about 350 g and has 100 billion neurons but only 25% of adult brain size. Synaptic connections are sparse and develop postnatally. Brain Development Plasticity: ◦ The brain's ability to adapt and form new connections throughout life. ◦ "Cells that fire together, wire together" explains synaptic strengthening. ◦ Synaptogenesis: Formation of new synapses; peaks during early childhood. ◦ Synaptic Pruning: Removal of unused connections; optimizes neural networks. Myelination: ◦ Process of insulating axons for faster neural transmission. ◦ Sensory systems (e.g., hearing) are fully myelinated at birth. ◦ Higher-order functions (e.g., abstract reasoning) develop later in life (after 20 years) Environmental Influences: ‣ Nutrition: Critical during prenatal development and early childhood. ◦ Example: Folic acid reduces neural tube defects; malnutrition impairs brain development (e.g., underdeveloped prefrontal lobes linked to ADHD).  ‣ Teratogens: Substances or environmental factors causing developmental impairments. Examples: ◦ Alcohol: FASD results in physical deformities, cognitive delays, and impulse control issues. ◦ Thalidomide: Causes severe limb deformities. ◦ Cigarette Smoke: Reduces oxygen flow, leading to premature birth and low birth weight. ◦ Heroin/Cocaine: Causes neonatal withdrawal symptoms. Motor Development Innate Reflexes: ◦ Automatic behaviors present at birth that aid survival. ‣ Rooting Reflex: Helps locate the breast for feeding; fades by 4 months. ‣ Moro Reflex: Startle response; arms spread wide; disappears by 2-3 months. ‣ Grasping Reflex: Enables infants to hold onto caregivers; fades by 5-6 months. ‣ Stepping Reflex: Precursor to walking; fades by 2-3 months. ◦ Learning to Walk: ‣ Gradual acquisition of motor skills: ‣ 6 months: Sits without support. ‣ 9 months: Pulls to stand, walks holding furniture. ‣ 12-15 months: Walks independently. Social Development Attachment: An emotional bond that provides security and persists over time. ◦ Imprinting - An instinctual tendency in some animals that produces a strong attachment to an adult. ◦ Key Theories and Studies:  ‣ Harlow’s Monkey Study: Baby monkeys preferred a soft, cloth-covered surrogate mother that provided comfort over a wire mother that provided food Demonstrated the importance of "contact comfort" over food in forming attachment. ‣ Bowlby’s Theory: Infants are born with innate behaviours, such as crying and smiling, designed to attract caregiving and promote bonding, essential for survival and emotional development. ‣ Ainsworth’s Strange Situation Test: Observed how infants responded to brief separations and reunions with their caregiver, categorizing attachment styles as secure, avoidant, ambivalent, or disorganized. This provided insight into the quality of the child-caregiver bond. Stranger anxiety: infants and young may children show distress when approached by a stranger. Separation anxiety – infants and young children may show distress when separated from their caregiver. Attachment Styles: ◦ Secure Attachment (65-70%): ‣ Distressed when caregiver leaves; easily comforted upon return. ‣ Linked to responsive caregiving. ◦ Avoidant Attachment (20-25%): ‣ Minimal distress during separation; avoids caregiver upon return. ‣ Linked to neglect or emotionally unavailable caregiving. ◦ Ambivalent Attachment (10-15%): ‣ High distress during separation; remains inconsolable upon return. ‣ Linked to inconsistent caregiving. ◦ Disorganized Attachment: ‣ Observed in children from abusive or highly neglectful environments. ‣ Characterized by fear, freezing, or contradictory behaviours. Romanian Orphan Studies: ◦ Showed severe developmental delays and disorganized attachment  due to deprivation in early caregiving environments. Attachment to Fathers: ◦ Develops around the same time as maternal attachment but differs in nature: ◦ Fathers are more associated with play, while mothers are linked to comfort. Role of Oxytocin: ◦ Hormone that promotes bonding and maternal behaviours. ◦ Released during childbirth, breastfeeding, and affectionate interactions.