developmental psychology

• The sensorimotor stage is the first stage of Piaget's theory, during which infants learn about the world through their senses and motor actions.
• In the preoperational stage, children begin to use symbols such as words and pictures to represent things in the real world.
• The sensorimotor stage (birth to 2 years) involves the development of perceptual-motor intelligence. Infants develop coherent patterns of behavior and develop object permanence.
• Life-span perspective:

  • Pattern of change that begins at conception and continues through the life-span
  • Development is lifelong, multidimensional, multidirectional, plastic, multidisciplinary, and contextual
• Nature of development:

  • Biological processes produce changes in an individual’s physical nature
  • Cognitive processes refer to changes in thought, intelligence, and language
  • Socioemotional processes involve changes in relationships, emotions, and personality
• Two rapidly emerging fields:

  1. Developmental cognitive neuroscience explores links between development, cognitive processes, and the brain

  2. Developmental social neuroscience examines connections between socioemotional processes, development, and the brain
• Periods of development:

  • Prenatal period: conception to birth
  • Infancy: birth to 18 or 24 months
  • Toddler: about 1 ½ to 3 years
  • Early childhood: 3 to 5 years
  • Middle & late childhood: about 6 to 10 or 11 years
  • Adolescence: approximately 10 to 12 years to 18 to 21 years
  • Early adulthood: early twenties through thirties
  • Middle adulthood: approximately 40 to about 60 years
  • Late adulthood: sixties or seventies until death
• Theories of development:

  • Psychoanalytic theory describes development as primarily unconscious and heavily colored by emotion
  • Freud's theory focuses on pleasure and sexual impulses in different stages
  • Erikson's psychosocial theory emphasizes psychosocial stages of development
• Piaget's Cognitive Developmental Theory:

  • Children go through four stages of cognitive development as they actively construct their understanding of the world
• 4 Stages of Cognitive Development:

  • Sensorimotor Stage:
  • Lasts from birth to 2 years of age
  • Infants construct an understanding of the world by coordinating sensory experiences with physical, motoric actions
  • Preoperational Stage:
  • Lasts from approximately 2 to 7 years of age
  • Children begin to represent the world with words, images, and drawings
  • Concrete Operational Stage:
  • Lasts from 7 to 11 years of age
  • Children can perform operations that involve objects and reason logically with specific examples
  • Formal Operational Stage:
• • Appears between ages of 11 and 15 and continues through adulthood
  • Individuals begin to think in abstract and more logical terms
• Vygotsky's Sociocultural Cognitive Theory:

  • Emphasizes how culture and social interaction guide cognitive development
  • Children's social interaction with skilled adults and peers is crucial for their cognitive development
• Information-Processing Theory:

  • Emphasizes that individuals manipulate information, monitor it, and strategize about it
  • Individuals develop a gradually increasing capacity for processing information, allowing them to acquire increasingly complex knowledge and skills
• Skinner's Operant Conditioning:

  • Consequences of a behavior produce changes in the probability of the behavior's occurrence
  • Rewards and punishments shape development according to B. F. Skinner
• Bandura's Social Cognitive Theory:

  • Behavior, environment, and cognition are key factors in development
  • Cognitive processes have important links with the environment and behavior
  • Observational learning is a key focus of Bandura's research
• Ethological Theory:

  • Behavior is strongly influenced by biology, tied to evolution, and characterized by critical or sensitive periods
• Natural selection is an evolutionary process where individuals best adapted to their environment survive and leave fit offspring
• Darwin's principle of natural selection states that nature allows those members of a species with genes that help them adapt to survive and reproduce
• Darwin's theory argues:

  • Genetic variation exists in a species
  • Some genes aid adaptation more than others
  • Genes aiding adaptation are passed to future generations more frequently
• Evolutionary psychology emphasizes adaptation, reproduction, and "survival of the fittest" in shaping behavior
• Fit refers to the ability to bear offspring that survive long enough to reproduce
• David Buss highlights how evolution influences human behavior, including decision-making, aggression, fears, and mating patterns
• Chromosomes are threadlike structures that come in 23 pairs, with one member from each parent, containing DNA
• Autosomes are twenty-two pairs, similar in males and females
• DNA is a complex molecule containing genetic information, made up of sequences of chemicals A, C, G, and T
• Genes help cells reproduce and manufacture proteins for life maintenance
• Mitosis is cellular reproduction where a cell's nucleus duplicates, forming two new cells with the same DNA in 23 pairs of chromosomes
• Mitosis continues throughout life, creating new cells for growth and replacing damaged cells
• Meiosis is a specialized cell division forming eggs and sperm (gametes)
• Fertilization is when an egg and sperm fuse to create a zygote
• A zygote is a single cell formed through fertilization, becoming a multiple-celled organism through cell division
• Identical twins develop from a single zygote that splits into two genetically identical replicas
• Fraternal twins develop from two eggs fertilized by different sperm, genetically no more similar than ordinary siblings
• Sex determination:

  • An XY zygote results in a genetic male
  • An XX zygote results in a genetic female
• Chromosomal abnormalities can result from gametes with abnormal chromosome numbers at conception
• Examples of chromosomal abnormalities:

  • Down Syndrome: extra chromosome causing intellectual disability and physical abnormalities
  • Klinefelter Syndrome (XXY): extra X chromosome causing physical abnormalities
  • Fragile X Syndrome: abnormality in the X chromosome causing intellectual disability and learning disabilities
  • Turner Syndrome (XO): missing X chromosome causing intellectual disability and sexual underdevelopment
  • XYY Syndrome: extra Y chromosome causing above-average height