Human Development: Theories and Research

The Study of Human Development

• Focuses on understanding the processes by which humans grow, change, and adapt throughout their lives.
• Covers themes like the nature of human development, theories, research methods, and the importance of context.

The Nature of Human Development

• A lifelong and dynamic process influenced by biological, cognitive, and socio-emotional factors.
• Studied from multiple perspectives that include the impact of nature vs. nurture, continuity vs. discontinuity, and stability vs. change.

Theories of Human Development

• Includes Freud's psychosexual theory, Erikson's psychosocial stages, Piaget's cognitive development theory, Vygotsky's sociocultural theory, and Skinner's behaviorism, all of which provide unique insights into human growth and behavior.

Research Methods in Human Development

• Research methods to study human development, such as longitudinal and cross-sectional studies.
• Scientific methods and ethical considerations in research are emphasized.

The Importance of Context

• Stresses that culture, environment, and historical time periods significantly influence individual growth.

Human Development Defined

• The process of change and stability in individuals throughout life, encompassing physical, cognitive, and socio-emotional development.
• Influenced by both hereditary and environmental factors.

Key Principles of Development

• Human development occurs across all stages of life, from conception through old age
• Involves biological, cognitive, and socio-emotional dimensions, each influencing the others.
• Development is flexible and subject to change.
• Individuals can adapt to various life circumstances, even later in life.
• Does not follow a straight, predictable path.
• Can involve growth and decline.
• Different aspects of development may progress at different rates.

Theoretical Perspectives

• Provides guidance on how to understand development while covering several key theories.
• Focuses on unconscious drives, emotional stages, and psychosocial development.
• Centers on how thinking and learning evolve over time.
• The Behavior Theories focuses on observable behaviors and the influence of the environment.
• Emphasizes the interconnectedness of individuals with their environment at multiple levels.

Nature vs. Nurture

• Human development is influenced by both genetic factors
• Environmental factors shape an individual's growth and personality.

Research Methods

• Descriptive research involves observing and recording behaviors or phenomena.
• Correlational research examines the relationship between variables to determine whether they are linked.
• Experimental research tests hypotheses through controlled experiments to establish cause-and-effect relationships.

The Lifespan Perspective

• A lifelong process that cannot be understood by only looking at one stage of life.
• Development is not limited to childhood or adolescence but continues through adulthood into old age.

Contexts of Development

• Development is shaped by multiple contexts.
• Cultural contexts include the values, customs, and traditions of the culture in which a person is raised.
• Historical contexts include the time period and historical events that influence development.
• Socioeconomic contexts include a person's social and economic position, which can affect access to resources and opportunities.

Heredity

• Refers to the biological and genetic inheritance from parents.
• Determines traits such as physical characteristics, temperament, and predispositions to certain illnesses.
• Also influences intelligence, personality traits, and potential talents.

Environment

• Includes all external factors that impact development, like family, culture, education, and social interactions.
• Socioeconomic status, parenting style, access to education, and peer influences play crucial roles.
• Environmental experiences shape cognitive and emotional growth.

Maturation

• The biological process of growth and development that unfolds in a genetically programmed sequence.
• Affects physical, cognitive, and emotional development.
• Environmental factors can influence the pace or outcome of development.

Family Context

• The most immediate and influential context.
• Parenting styles, sibling relationships, and home environment impact emotional and social growth.

Socioeconomic Context

• Access to resources such as education, healthcare, and nutrition influences development.
• Higher socioeconomic status (SES) often provides more opportunities.
• Lower SES may present challenges like stress and limited access to enrichment activities.

Cultural Context

• Cultural values and traditions shape beliefs, behaviors, and expectations.
• Individualistic cultures emphasize independence, while collectivist cultures prioritize community and family.

Historical Context

• The time period in which a person grows up influences their development.
• Technological advancements, societal norms, and historical events shape experiences and opportunities.

Normative and Nonnormative Influences

• Normative influences are common experiences.
• Nonnormative influences are unique, unpredictable events.
• Age-graded influences: Biological and social changes that occur at predictable ages.
• History-graded influences: Events experienced by an entire generation.
• Nonnormative influences: Life events that do not follow a predictable pattern.

Timing of Influences

• The timing of experiences can significantly impact development.
• Critical periods are a specific time in which experiences must occur for normal development to take place, that potentially resulting in permanent affects in missed.
• Sensitive periods are a time when a person is especially responsive to certain experiences, but development is still possible outside of this window.

Paul B. Baltes' Life-Span Developmental Approach

• Development is a lifelong, dynamic process influenced by biological, psychological, and social factors.
• Each life stage brings new challenges, growth, and change, with no "dominant" period.
• Influenced by multiple domains that include biological, Cognitive and Socioemotional.
• Not a straight path; it involves both gains and losses, with some abilities improving while others decline.
• Human abilities and behaviors can be modified with effort, practice, and the right environment.
• Shaped by multiple interacting influences like Normative age-graded influences, Normative history-graded influences, and Nonnormative influences.
• People aim to gain new skills, maintain current abilities, and manage losses across life.
• Influenced by biology and culture.
• Young individuals focus on growth, while older adults focus more on maintaining abilities and adapting to age-related declines.

Theoretical Issues in Development

• Asks if development is active or reactive or continuous or discontinuous.
• Shapes various theories of development and influence research in psychology, education, and human behavior.

Development Active or Reactive

• The reactive perspective suggests that individuals respond to external stimuli.
• The active perspective suggests that individuals play a role in their own development.
• Individuals respond to their environment, they also shape their own experiences through choices, behaviors, and interactions.

Development Continous or Discontinous

• Continuous development suggests that development happens gradually, building on previous abilities.
• Discontinuous development suggests that development happens in qualitative leaps, with individuals progressing through distinct stages.
• Some aspects of development are continuous, while others show stages of change, depending on the domain being studied.

Theoretical Perspectives

• Psychoanalytic perspective focuses on the unconscious mind, emotions, and early experiences.
• Learning perspective focuses on how external influences, environment, and experience shape behavior.
• Cognitive perspective focuses on how people think, learn, and process information over time.
• Contextual perspective emphasizes that development is influenced by multiple systems and environments surrounding an individual.
• Evolutionary/Sociobiological perspective examines development through evolution, genetics, and biological survival mechanisms.

Psychoanalytic Perspective

• Theorists include Sigmund Freud (psychosexual theory) and Erik Erikson (psychosocial theory).
• Development occurs through eight stages, each involving a psychosocial conflict that must be resolved.
• Early childhood experiences shape personality and behavior.

Learning Perspective

• Theorists include Ivan Pavlov & B.F. Skinner (behaviorism) and Albert Bandura (social learning theory).
• Development is a result of conditioning (learning through reinforcement and punishment).
• Emphasizes observational learning (modeling behavior by watching others).

Cognitive Perspective

• Theorists are Jean Piaget (cognitive development theory) and Lev Vygotsky (sociocultural theory).
• Children go through four stages of cognitive development: sensorimotor, preoperational, concrete operational, and formal operational.
• Children actively construct knowledge through experiences.

Vygotsky's Sociocultural Theory

• Emphasizes the role of social interaction and culture in cognitive development.
• Introduces the Zone of Proximal Development (ZPD), the gap between what a child can do alone and what they can do with guidance.

Contextual Perspective

• Theorist: Urie Bronfenbrenner (bioecological model).
• Five environmental systems: microsystem, mesosystem, exosystem, macrosystem, and chronosystem.
• Development occurs within these environmental systems:
  • Microsystem - Immediate relationships, family, school, peers.
  • Mesosystem - Interactions between microsystems, e.g., parent-teacher meetings.
  • Exosystem - Indirect influences, e.g., a parent's workplace affecting home life.
  • Macrosystem - Cultural and societal influences, e.g., laws, traditions, economy.
  • Chronosystem - Life changes over time, e.g., historical events, personal milestones.

Evolutionary/Sociobiological Perspective

• Theorist: Charles Darwin (evolutionary theory).
• Behaviors and traits that enhance survival and reproduction are passed down.
• Natural selection and adaptation shape human behavior.

Sampling

• Selects participants for the study
• Types of sampling:
  • Random Sampling - Every individual in the population has an equal chance of being selected, ensures unbiased results.
  • Stratified Sampling - The population is divided into subgroups, participants are selected from each subgroup proportionally.
  • Convenience Sampling - Participants are chosen based on availability and willingness, that may not be fully representative.
  • Longitudinal Sampling - The same group of people is studied over time, helps track changes in development.

Importance of Sampling:

• A well-selected sample ensures that research findings can be generalized to the larger population.

Forms of Data Collection

• Participants provide information about their thoughts, behaviors, and experiences.
  • Can be structured (fixed Q's) or unstructured (open-ended discussions).
  • Can be biased due to social desirability.
• Researchers observe and record behavior in real-world settings without interference.
  • Provides real-life, authentic data.
  • Can be time-consuming; observer bias may affect results.
• Behavior is studied in a controlled setting, variables can be manipulated.
  • More control over conditions; easier to isolate variables.
  • Artificial settings may not reflect real-world behavior.
• Standardized tests measure intelligence, memory, language, or problem-solving abilities.
  • May not capture all aspects of development.
• Biological data is collected through brain scans , heart rate monitoring, or hormone level analysis.
  • Provides objective data not influenced by self-report bias.

Basic Research Designs

• Provides a framework that guides how a study is conducted.
• Experimental design manipulates one or more variables to determine cause-and-effect relationships.
  • Participants are randomly assigned to control and experimental groups.
  • Strongest evidence for causation.
  • May not always reflect real-life situations.
• Correlational Design examines relationships between variables without manipulating them.
  • Can identify links between factors.
  • Does not establish causation.
• Case studies have in-depth analysis of an individual or small group over time.
  • Provides rich, detailed insights.
  • Cannot be generalized to the broader population.

Developmental Research Designs

• Developmental psychologists study how people change over time.
• Longitudinal Study involves the same individuals studied over a long period, showing long-term developmental trends and individual differences.
• Cross-Sectional Study compares individuals of different ages at a single point in time, which is quick, cost-effective.
• Sequential studies combines Longitudinal & Cross-Sectional, is used to follow multiple age groups over time, which helps to separate age effects from generational effects.

Ethics of Research

• In Developmental Psychology ensures that research protects the well-being of participants, especially vulnerable populations like children and the elderly.
• Provides informed consent, confidentiality, and protection from harm.
• Has the right to withdraw and get a debriefing.
• Studies involving human participants must be approved by Institutional Review Boards to ensure compliance with ethical standards.

Fertilization

• The process where a sperm cell from the father unites with an egg cell from the mother to form a new organism called a zygote.
• Occurs during Ovulation where the uterus releases an egg that lasts for 12-24 hours.
• Sperm travels though the cervix, uterus, and fallopian tubes in order to penetrate the egg where genetic material from the sperm (23 chromosomes) and the egg (23 chromosomes) combine, forming a full set of 46 chromosomes.
• Implantation occurs when the zygote becomes a blastocyst that travels to the uterus where it implants into the uterine lining.

Sex Determination:

• 23rd chromosome pair determines the baby's biological sex.
• the mother always contributes an X chromosome.
• Father contributes either an X (girl) or Y (boy) chromosome.
• The Y chromosome contains the SRY gene, which triggers the development of male characteristics.
• Without the SRY gene, the embryo develops as female by default.

Multiple Births

• Occurs when a woman conceives more than one baby during a single pregnancy.
• The two types of twins include Identical & Fraternal.
• Fraternal twins result from two separate eggs being fertilized by two different sperm with about 50% of their genetic material.
• Factors influencing multiple births can be family history, maternal age, fertility treatments & ethnicity.

Genetic Code

• Traits Stored in DNA that determines physical traits of the individual and is passed down.
• Gene are segments of DNA that contain instructions for building proteins, which influence traits like eye color, height, and intelligence.
• Chromosomes are Structures in the nucleus of cells that carry genetic information, Humans have 46 chromosomes (23 pairs).
• Alleles are dIfferent forms of a gene.

What Determines Sex?

• Determined by the 23rd pair of chromosomes.
  • Males XY
  • Females XX

Patterns of Genetic Transmission

• Dominant and Recessive Inheritance:
  • dominant traits require 1 copy of a dominant allele ex. brown eyes
  • recessive traits require 2 copies of the dominant allele one from each parent ex. blue eyes
• Polygenic Inheritance:
  • Traits are controlled by multiple genes rather than a single gene ex. height, skin color, intelligence, personality
• Sex-Linked Inheritance:
  • Some traits are linked to the X-chromosome making them more common in males ex. colorblindness, hemophilia

Genetic and Chromosomal Abnormalities:

• Caused during genetic transmission that affects genetics
• Can be inherited or occur as spontaneous mutations. Types
• Single gene mutations, chromosomal abnormalities

Chromosomal Abnormalities:

• occurs as an extra missing or altered chromosome
• Some include Down syndrome (Extra chromosome 21)

Genetic Counseling and testing:

• Help families understand risks of genetic disorders to make informed choices.
• testing involves analyzing DNA to detect genetic disorders
• Common tests include Carrier screening, Amniocentesis, Chronic villus sampling, Newborn screening

Ethical Concerns of Genetic Testing

• includes privacy issues
• Potential discrimination based on genetic information

Nature and Nurture Factors

• Nature(genetics)
• Nurture(environment)

Heredity and Environment Study Methods:

• Family, twins, adoptions
• measure the proportion of variation in a trait due to genes (on a scale from 0 to 1 ranging in intelligence (0.50 to 0.70)

How Heredity and Environment interact

• genes sets a range for a potential trait
• Traits are resistant to environmental influences
• Genes and environment work in specific patterns

Interactions of Genes and Environment Types

• Passive Correlation- Parents provide both genes and environment
• Active Correlation- a child’s choices match their genes
• Evocative Correlation- a child’s genetic traits influences how others respond

Influences from Heredity and the Environment

• Intelligence= 50-70% inherited
• Personality- extroversion, agreeableness, and neuroticism have a genetic bias
• Mental Health- disorders like schizophrenia, depression, and anxiety run in families
• Physical Health- susceptibility to diseases like, diabetes or cancer is inherited
• Language development- ability to acquire language is biologically programed

Stages of Prenatal Devlopment

• Germinal Stage (Weeks 1-2)
  • begins at conception and forms a zygote
• Embryonic stage (Weeks 3-8)
  • organs form (organogenesis)
• Fetal stage (Week 9- Birth)
  • rapid grow in size
  • fetus responds to sounds and light

Maternal Factors

• nutrition
• teratogens
• age
• stress and health

Maternal state influence’s in prenatal development

• diet and nutrients
• substance intake
• cortisol and stress levels

Partenal Factors

• sperm quality
• health and lifestyle
• mutations to genes transfer
• Exposure to toxins

Disparities in Prenatal Care

• Socio economic status , geographic or racial barriers influence the care required

Access to prenatal solutions

• programs, outreach and a reduction of economic bias promotes better care in pregnancy

Medical check ups and screenings

• health exams, genetic screening help with identifying potential issue that could effect pregnancy

Harmful Substances

• quitting smoking and alcohol influences a healthy baby growth

Emotional and mental Health

• managing stress and depression is essential

Stages of Childbirth ( the way child birth has changed over time)

Birth process

• Influenced by the culmination of pregnancy

3 stages to child birth (initiated by hormonal changes)

• Stage 1- labor (the longest)
• Stage 2- delivery
• Stage 3 - expulsion of placenta
• Can be vaginal, medicated/ non medicated
• Natural way of childbirth has faster recovery
• Caesarean section (C-section)- delivery of the baby through the abdomen

Electronic Fetal Monitoring (EFM)

• Detects early fatal distress and provides support for various decisions to be made for the baby
• High risk can lead to unnecessary medical interventions if misinterpreted.

The Newborn Baby (undergoes physiological and adjustments)

• Average weight: (5.5 to 10 pounds) and average length (18 to 22 inches)
• Skin may be reddish swollen, with various reflexive movements
• body system must function independently for the first time (taking its first breath)
• 1. Apgar Score checks baby’s physical condition scoring 0, 1 or 2 in five categories
• 2. Newborn screening tests to detect genetic or metabolic disorders, identifies hearing loss

###Automatic Newborn Reflexes

• Rooting: turns head when cheek touched
• Sucking: sucks when cheek touched
• Grasp: finger curl when hand is toughed

Newborns behavior states

• sleeping
• feeding influence responses to stimulation

Support for better baby health

• kangaroo skin to skin
• Talking, singing
• nutrition and healthcare

Low birth weight babies

• weight less than 5.5 pounds may involve high risk to breathing and temperature levels
• Treated through Neonatal support, incubators, Kangaroo Care and feeding

Overdue Babies(Post Maturity)- born after 42 weeks

• can impact the growth and weight levels , often involves inductions

Still Birth

• The death of a baby after 20 weeks of pregnancy Coping With - parental support, autopsy, genetic testing

All are assisted through a supportive envrionment

Death During Infancy

• refers to baby deaths before there 1st birthday’s.
• main prevention access’s to Healthcare+ prenatal safe hygiene care is essential

Importance of Immunizations

• Prevents serious infections
• Reduces infant mortality
• Protects the communities

###Principles Of Development

• Cephalocaudal- Growth is from head to toe
• Porximodistal-starts from the center outward
• Hierarchical integration- Simple skills develop first
• Independence of systems- different system develop at different rates

Patterns of growth

• Growth in infancy is uneven with different parts of body growing at rapid pace (weight and height vary)

###Nutrition for Babies

• breast milk provides nutrients
• Solid food should be introduced around 6mn range
• Limit foods and high sugars impact healthy function

###Brain and behavior

• Develops rapidly at the at first 2 years
• Neurons form strong connections at birth
• Reflex behaviors have automatic reflexes essential for survival.

###Sensory Capacities

• Babies experience the world through senses seeing best at 8-12 inches +hearing and tasting

Early sensory capacity

• skin to skin can promote most sense at birth for babies

Motor Development milestones

• Motor Development (the emergence of movement in babies ) 2 types :
  • Gross Involves large groups ,Fine small movements
• Motor skills closely link to perceptions
• Sensory Stimulation (touch; movement) is key

###Gibson’s Theory - Ecological Theory

• Motor is driven through infant’s ability to perceive and interact

###Gibson’s Concepts

• Affordances - Objects that provide opprounties

###Thelen’s dynamic

• systemsTheory - influenced by many factors
• Motors skills from interaction of different system