Developmental Psychology: An Introduction

Introduction to Developmental Psychology

• Developmental psychology focuses on identifying and explaining continuities and changes in individuals
• Human development scientifically studies change and stability throughout life
• Life-span development views human development as a lifelong process that can be scientifically studied
• Physical development includes growth of the body and brain, changes in sensory abilities, motor skills, and overall health
• Cognitive development involves changes in mental abilities like learning, attention, memory, language, thinking, reasoning, and creativity
• Psychosocial development involves changes in emotions, personality, and social relationships
• Social construction is a concept that seems natural but is invented by a specific culture or society
• Individual differences are variations in characteristics, influences, and developmental outcomes
• Heredity refers to inborn traits inherited from biological parents
• Environment encompasses all nonhereditary and experiential influences on development
• Maturation is the natural unfolding of physical and behavioral changes
• A nuclear family consists of one or two parents with their biological, adopted, or stepchildren
• Extended families are multigenerational networks of parents, children, and other relatives, sometimes living together
• Socioeconomic status (SES) includes economic and social factors like income, education, and occupation
• Risk factors are conditions increasing the likelihood of a negative developmental outcome
• Culture is a society's total way of life, with customs, traditions, beliefs, values, language, and physical products
• Ethnic groups share ancestry, race, religion, language, or national origins, contributing to a sense of identity
• Plasticity is the range of modifiability of performance
• Quantitative change involves changes in number or amount
• Qualitative change involves discontinuous changes in kind, structure, or organization

Theories and Psychosexual Development

• Sigmund Freud developed the theory of psychosexual development
• Psychosexual development includes an unvarying sequence of childhood stages with gratification shifting from the mouth to the anus and then to the genitals
• The Oral stage occurs from birth to 12-18 months, where pleasure comes from sucking and feeding
• The Anal stage occurs from 12-18 months to 3 years, where gratification comes from withholding and expelling feces, and toilet training is important
• The Phallic stage occurs from 3 to 6 years, where a child becomes attached to the opposite-sex parent; superego develops; gratification moves to the genital region
• The Latency stage occurs from 6 years to puberty, and is a time of relative calm
• The Genital stage occurs from puberty through adulthood, where sexual impulses re-emerge and are channeled into mature sexuality

Psychosocial Development

• Erik Erikson developed the theory of psychosocial development, focusing on the socially and culturally influenced ego
• Basic trust versus mistrust occurs from birth to 12-18 months, where a baby develops a sense of the world being good and safe; virtue is hope
• Autonomy versus shame and doubt occurs from 12-18 months to 3 years, where a child develops independence; virtue is will
• Initiative versus guilt occurs from 3 to 6 years, where a child develops initiative; virtue is purpose
• Industry versus inferiority occurs from 6 years to puberty, where a child learns skills; virtue is skill
• Identity versus identity confusion occurs from puberty to young adulthood, where adolescents determine their sense of I; virtue is fidelity
• Intimacy versus isolation occurs in young adulthood, where individuals seek commitment; virtue is love
• Generativity versus stagnation occurs in middle adulthood, where adults guide the next generation; virtue is care
• Integrity versus despair occurs in late adulthood, where older adults accept their lives; virtue is wisdom

Learning and Cognitive Perspectives

• Learning perspective views that changes in behavior result from experience or adaptation
  • Behaviorism emphasizes the environment's role in observable behavior
• Ivan Pavlov studied classical conditioning by observing dogs salivating to meat
• John B. Watson furthered classical conditioning through associating a stimulus that does not ordinarily elicit a response with one that does
• B. F. Skinner studied operant conditioning, which associates behavior with its consequences
  • Reinforcement strengthens behavior and increases likelihood of it being repeated
  • Punishment weakens behavior and decreases likelihood of it being repeated
• Jean Piaget's cognitive perspective views thought processes as central to development
  • Cognitive-stage theory says that cognitive development advances in four distinct stages
  • Adaptation involves adjusting to new environmental information through assimilation and accommodation
    • Assimilation incorporates new information into existing cognitive structure
    • Accommodation changes cognitive structures to include new information

Sociocultural and Ecological Theories

• Lev Vygotsky's sociocultural theory focuses on contextual factors affecting children's development
• The zone of proximal development (ZPD) is the difference between what a child can do alone and with help
• Scaffolding is temporary support to help a child master a task
• Urie Bronfenbrenner's contextual perspective views the individual as inseparable from the social context
• Bronfenbrenner's bioecological theory identifies five levels of environmental influence
  • Microsystem: Home, family, siblings
  • Mesosystem: Connections
  • Exosystem: Community
  • Macrosystem: Culture, government
  • Chronosystem: Time

Quantitative and Qualitative Research

• Quantitative research deals with objectively measurable data
  • It involves identifying a problem, forming hypotheses, collecting data, statistically analyzing the data, forming conclusions, and disseminating findings
• Qualitative research focuses on non-numerical data like subjective experiences, feelings, or beliefs
• A sample is a group of participants chosen to represent the entire population under study
• Random selection ensures each person in a population has an equal chance of being chosen

Forming a New Life

• Fertilization is a union of sperm and ovum, producing a zygote (also called conception)
• Zygote: The one-celled organism resulting from fertilization
• Dizygotic twins are conceived from two different ova with two different sperm cells and are no more alike than other siblings
• Monozygotic twins result from the division of a single zygote after fertilization and genetically are similar
• Deoxyribonucleic acid (DNA) carries inherited instructions for the development of all cellular life forms
• Genetic code is a sequence of bases within the DNA molecule that governs the formation of proteins
• Chromosomes: Coils of DNA that consist of genes
• Genes are small segments of DNA located in definite positions on particular chromosomes
• Human genome is a complete sequence of genes in the human body
• Mutations are permanent alterations in genes or chromosomes
• Autosomes are the 22 pairs of non-sex-related human chromosomes
• Sex chromosomes determine sex which is XX in females, XY in males
• Alleles are alternative forms of a gene
• Homozygous possessing two identical alleles
• Heterozygous possessing differing alleles
• Dominant inheritance occurs when a child receives different alleles, only the trait of dominant allele is expressed
• Recessive inheritance occurs when a child receives two identical recessive alleles, and only then the non-dominant trait is expressed
• Polygenic inheritance occurs with multiple genes at different sites on chromosomes
• Phenotype is a person’s observable characteristics
• Genotype is a person’s genetic makeup which affects many characteristics.
• Multifactorial transmission involves a combination of both genetic and environmental factors for complex traits
• Epigenesis is a mechanism that turns genes on or off
• Incomplete dominance occurs when a child receives two different alleles, resulting in partial expression of a trait
• Sex-linked inheritance affects certain inherited X chromosome characteristics inherited from the mother
• Down syndrome: A chromosomal disorder characterized by moderate to severe mental retardation, also called trisomy-21
• Genetic counselling aims to advise prospective parents of having children with hereditary defects
• Behavioral genetics quantitatively studies hereditary and environmental influences on behavior
• Heritability statistically estimates heredity's contribution to individual differences
• Concordant refers to the tendency of twins sharing the same trait or disorder
• Reaction range is the degree of potential variability based on environmental conditions
• Canalization limits expression variance for inherited characteristics
• Genotype-environment interaction is the portion of phenotypic variation from genetically unique individuals reacting to similar environments
• Genotype-environment correlation involves the tendency of genetic and environmental influences reinforcing each other
• Niche-picking is the tendency of a person seeking environments compatible with their genotype

Prenatal Development

• Obesity is extreme overweight in relation to age, sex, height, and body type
• Temperament is a characteristic disposition of approaching & reacting to situations
• Schizophrenia is a mental disorder with symptoms including loss of contact with reality, hallucinations, & delusions
• Gestation is the period of development between conception & birth
• Gestational age is the age of an unborn baby from mother's last menstrual cycle
• Cephalocaudal and proximodistal principles dictates parts of body develop
• Stages of prenatal development
  • Germinal stage: First 2 weeks
  • Embryonic stage: 2-8 weeks
  • Fetal stage: 8 weeks to birth
• Spontaneous abortion is natural expulsion from the uterus of an embryo that can’t survive
• Ultrasound: medical procedure using high frequency sound waves
• Teratogen: environmental agent that can interfere with normal prenatal development
• Fetal alcohol syndrome (FAS) is a set of abnormalities affecting offspring
• Acquired immune deficiency syndrome (AIDS): viral disease undermining functioning of the immune system
• Stress: physical or psychological demands on a person

Birth and Newborn Care

• Labor is the process of giving birth
• Parturition is the act of giving birth
• The stages of childbirth are dilation of the cervix, descent and emergence of the baby, and expulsion of the placenta
• Electronic fetal monitoring mechanically monitors fetal heartbeat during labor and delivery
• Caesarean delivery involves surgical removal of the baby from the uterus
• Natural childbirth prevents pain through education and training in breathing and relaxation
• Prepared childbirth uses instruction, breathing exercises, and social support
• Doula: experienced mentor furnishes emotional support and information
• Neonatal period: First 4 weeks of life is a time of independent existence
• Neonate: newly born baby, up to 4 weeks old
• Anoxia is lack of oxygen that may cause brain damage
• Neonatal jaundice appears yellowish caused by liver immaturity
• Apgar scale measures a newborn’s condition
• Brazelton Neonatal Behavioral Assessment Scale (NBAS) tests neonate’s responses
• State of arousal: an infant’s physiological and behavioral status
• Low-birth-weight babies are less than 5½ pounds (2,500 grams)
• Preterm infants are born before completing the 37th week of gestation
• Small-for-date infants have <90% birth weight as others
• Kangaroo care: new-born is laid face down between the mother’s breasts
• Stillbirth is death of fetus at/after of the 20th week
• Infant mortality rate Proportion of babies born alive die within the 1st year
• Sudden infant death syndrome (SIDS) is the sudden, unexplained death of an healthy infant
• Nerve cells integration coordinates muscle group activities
• Differentiation occurs by acquire specialized structures and functions
• Cell death brain development, Normal elimination of excess brain cells

Motor Skill Development

• Myelination coats neural pathways allowing faster communication
• Reflex behaviors are automatic, involuntary, & innate responses to stimulation
• Plasticity modifies or molds the brain through experience
• Systems of action are increasingly complex combinations of motor skills
• Denver Developmental Screening Test is a screening test conducted for 1 month to 6 years old children
• Gross motor skills involve large muscles
• Fine motor skills involve small muscles and eye-hand coordination
• Visual guidance allows use of the eyes to guide movements
• Haptic perception can aid in acquiring information by handling objects
• Depth perception allows ability to perceive surfaces 3-dimensionally
• Visual cliff gives an illusion of depth
• Ecological theory of perception Eleanor and James Gibson
• Dynamic systems theory Esther Thelen