Chapter 1: Introduction to Lifespan Development

LIFESPAN DEVELOPMENT • Coverage: • • • • • • • • • • • • Introduction to Lifespan Development Lifespan Perspective Conceptions of Age Periods of Development Issues in Lifespan Development Historical Theories on Development Contemporary Theories on Development Descriptive Research Correlational Research Experimental Research Research Involving Time-Spans Conducting Ethical Research Introduction to Lifespan Development What is Lifespan Development? • The scientific study of how people change and stay the same from birth to death. • Focuses on physical, cognitive, language, and psychosocial development, including family and peer influences. Growth of the Field: • Initially focused on infants and children. • Expanded to include adolescence, adulthood, and aging. • Development isn't seen as finished by age 25 – adults continue to grow and change. • Research on adulthood is growing, especially with the aging "baby boomers." Changing Views on Development: • Early childhood experiences no longer seen as the sole influence on future development. • Lifespan development emphasizes growth throughout life and how experiences shape us. • Adulthood is seen as a time of ongoing cognitive, social, and psychological development. Connections to Other Fields: • Informs applied areas like educational psychology, psychopathology, and forensic developmental psychology. • Links to other research fields, such as social psychology, cognitive psychology, and comparative psychology. Draws from other sciences like biology, sociology, healthcare, nutrition, and anthropology. Lifespan Perspective Principles of Lifespan Development (Paul Baltes) • Development is lifelong: Change occurs throughout life, with no specific age being more important than another. • Development is multidirectional: People experience both growth and loss across various aspects of life (e.g., finishing school, marriage, becoming a parent). • Development is multidimensional: Changes happen in three main areas: o Physical: Changes in body, health, and senses. o Cognitive: Changes in thinking, memory, and intelligence. o Psychosocial: Changes in emotions, relationships, and selfidentity. o These domains interact with each other, meaning one change can affect others. • Development is multidisciplinary: Lifespan development draws on knowledge from many academic fields like psychology, biology, and sociology. • Development is characterized by plasticity: People have the ability to change throughout life, such as how the brain can adapt and recover from injury. • Development is multicontextual: Development is influenced by various contexts: o Normative age-graded influences: Shared experiences at a specific age (e.g., childhood, adolescence). o Normative history-graded influences: Experiences tied to the time period and historical events (e.g., Baby Boomers growing up in the 1960s). o Non-normative life influences: Unique, individual experiences that shape development (e.g., losing a parent early). Social Contexts Affecting Development • Socioeconomic Status (SES): A family's income, education, and occupation impact their lifestyle, parenting, and stressors. 1|Hikamac chi LIFESPAN DEVELOPMENT o Higher SES families tend to have better job security, higher education, and better health. o Lower SES families may experience more stress, health issues, and unstable jobs. o Poverty: Families below the poverty line face difficulties in maintaining a household, and poverty is linked to poorer health, lower life expectancy, and other challenges. Cultural Context • Culture: Shared beliefs, values, behaviors, and practices that guide society. It influences how we live and develop. • Ethnocentrism: Belief that one's own culture is superior. This can hinder understanding of other cultures. • Cultural Relativity: Understanding that cultural practices should be evaluated within their own cultural context. • Cultural Impact on Development: Human development is shaped by cultural values and practices, and understanding this is crucial when studying development across cultures. Lifespan vs. Life Expectancy • Lifespan: The maximum length of time a species can live under optimal conditions (e.g., a human's potential lifespan can be over 120 years). • Life Expectancy: The average number of years a person born in a particular period can expect to live, which can vary based on historical, social, and health factors. Conceptions of Age Chronological Age • This is the most common way to measure age: the number of years since birth. • However, we don’t always feel the same as our chronological age. We might feel older or younger depending on our health, stress, or mood. Other Ways to Think About Age • Biological Age: o Refers to how quickly your body is aging. o Factors that influence biological age include nutrition, physical activity, sleep habits, stress management, smoking, alcohol use, and genetics. • Psychological Age: o • This refers to how mentally and emotionally mature you are compared to others your age. o For example, someone may be 20 years old but have the mental capacity of an 8-year-old, or a 70year-old might be learning new skills and traveling. o Your psychological age reflects how adaptable and excited you are to face new challenges. Social Age o Based on cultural expectations for people of a certain age. o Social age considers milestones like finishing education, getting a job, moving out, marrying, or retiring. o Social age norms are changing— many people are reaching these milestones later or not at all. Periods of Development Prenatal Development • Starts at conception and ends at birth. • Focus on forming body structures, maternal health, and avoiding harmful environmental factors (teratogens). Infancy and Toddlerhood • From birth to age 2. • Rapid physical growth and development (e.g., learning to walk, talk). • Caregivers become more involved in guiding and ensuring safety as the child becomes mobile. Early Childhood • From ages 2 to 6 (preschool years). • Children learn language, develop a sense of self, and gain more independence. • Begin to understand the physical world around them. Middle and Late Childhood • From ages 6 to puberty. • Focus on learning academic skills and building friendships. • Children start comparing themselves to others and gaining self-awareness. Adolescence • From puberty to around age 18. • Physical changes (puberty) and cognitive development (thinking abstractly about concepts like love, fear, freedom). • Adolescents may feel invincible, which can lead to risky behaviors. Emerging Adulthood • Ages 18 to 25. 2|Hikamac chi LIFESPAN DEVELOPMENT • A transitional period between adolescence and full adulthood. • Continued exploration of identity and gaining independence from parents. • Peak physical health, but high risk for substance abuse and crime. Early Adulthood • From ages 25 to 40-45. • Focus on building intimate relationships, starting families, and establishing a career. Middle Adulthood • From ages 40-45 to 65. • Aging becomes more noticeable; many people are at their peak productivity in love and work. Late Adulthood • From age 65 onward. • Often divided into: o Young-old (ages 65-84): Generally healthy, active, and independent. o Oldest-old (ages 85+): Increased health risks, such as heart disease and cancer, and more dependence on others. Issues in Lifespan Development Nature vs. Nurture • This debate explores whether our traits (e.g., height, personality, health) are shaped by heredity (genetics) or environment (e.g., lifestyle, diet). • Most scholars agree that both nature (genetics) and nurture (environment) interact and contribute to our development, making it hard to say one is more important than the other. Continuity vs. Discontinuity • This issue asks whether development is gradual or marked by distinct stages. • Stage theories (e.g., Freud, Piaget) believe development occurs in clear, separate stages that are very different from each other. This is known as discontinuous development. • Continuous development (e.g., behaviorists, Vygotsky) suggests development is gradual, with skills becoming more advanced over time, but not fundamentally new. Active vs. Passive • This question considers how much control we have over our development. • Some theorists (e.g., Piaget) believe people are active participants in their development, actively exploring and shaping their own growth. • Others (e.g., behaviorists) see people as more passive, shaped largely by genetics and the environment. Stability vs. Change • This debate asks if our early traits (e.g., personality) stay the same throughout life or if they change over time. • Some theorists argue that core traits are stable, while others believe these traits can change due to social and cultural influences over time. Historical Theories on Development Preformationist View • In the 18th century, children were thought to be little adults. • Preformationism believed that a tiny, fully formed human existed in the sperm or egg and simply grew until birth. Development was seen as a process of unfolding already existing abilities. o The environment was not thought to influence development. John Locke (1632-1704) • Locke rejected the idea of innate knowledge and argued that children are shaped by their environment, especially education. • He introduced the idea of the mind as a tabula rasa (blank slate), with children learning from their experiences. • Locke’s ideas influenced behavioral theories, where development is shaped through learning, rewards, punishments, and social interactions. Jean-Jacques Rousseau (1712-1778) • Rousseau believed children are not "little adults" and that development follows a natural plan. • He argued children should be allowed to think for themselves and develop according to their own biological timetable. • Rousseau’s ideas are considered the foundation of developmental psychology, influencing figures like Piaget. Arnold Gesell (1880-1961) • Gesell believed that children's development is driven by genes through a process called maturation. • He thought development unfolds in fixed sequences and opposed teaching children things before their nervous systems were ready. • Gesell’s research focused on neuromotor development at the Yale Clinic of Child Development. Sigmund Freud (1856-1939) 3|Hikamac chi LIFESPAN DEVELOPMENT • • • • Freud emphasized the role of early childhood experiences in shaping personality and behavior. He believed humans are driven by instincts, and childhood experiences influence how we manage and transform those instincts into socially acceptable behavior. Freud’s ideas formed the psychodynamic perspective, focusing on psychosexual development. His theory faced criticism for being hard to test scientifically and for relying on unverified case studies. Later theories like behaviorism and humanism challenged Freud’s ideas. Contemporary Theories on Development Erikson’s Psychosocial Theory • Erikson developed 8 stages of development that span the entire lifespan. • Each stage represents a psychosocial crisis that needs to be resolved for positive development. • If a crisis isn’t resolved, it can affect future stages. • Example: If someone doesn’t develop trust (stage 1), they may struggle with intimacy in adulthood (stage 6). • Critics argue Erikson focused too much on crises and assumed each stage must be completed before the next. Learning Theory (Behaviorism) • Based on the idea that only observable behavior should be studied. • B.F. Skinner expanded behaviorism, focusing on stimulus-response and using rewards to shape behavior. • Skinner’s work showed how learning and reinforcement can change behavior. • Key Contribution: Behaviorism helped understand the nature-nurture debate and human free will. Social Learning Theory (Albert Bandura) • Bandura emphasized learning through observation and imitation (e.g., children copying behavior they see). • He introduced reciprocal determinism, which means we shape our environment and vice versa. • Example: Parents influence a child's behavior, but children also impact how parents act. • Bandura’s famous experiment involved children watching adults act aggressively toward a “Bobo” doll, and then mimicking the same behavior. Cognitive Theories • Focus on how mental processes (like thinking and reasoning) change over time. • Jean Piaget o Piaget believed children’s intelligence develops through 4 stages of cognitive growth (sensorimotor, preoperational, concrete operational, formal operational). o His work showed that children think differently than adults and that development happens through maturation, not just learning. o Criticism: Piaget overemphasized maturation and ignored cultural influences on development. • Lev Vygotsky o Vygotsky focused on the role of culture and social interaction in cognitive development. o He believed children have a set of potential abilities that can be developed with help from others (guidance). o Vygotsky’s theories are influential in education today. • Information Processing o Focuses on how people perceive, analyze, and remember information. o It sees cognitive development as continuous, where skills improve gradually, with the brain maturing and environmental interactions aiding development. Bronfenbrenner’s Ecological Systems Theory • This theory focuses on the many systems that influence human development. • It looks at how different social environments (family, school, community, culture) impact an individual: o Microsystem: Direct, immediate environments (family, school). o Mesosystem: Interactions between systems (e.g., homeschool relationship). o Exosystem: Larger community context (e.g., local economy). o Macrosystem: Cultural values and global factors (e.g., economy, societal norms). 4|Hikamac chi LIFESPAN DEVELOPMENT o • o Chronosystem: The influence of time (historical period, generational changes). This theory highlights the interconnectedness of all these influences on an individual’s development. Research Methods in Psychology • • Scientific Method: This is a systematic process used by scientists to collect, analyze, and interpret data. It keeps questioning and skepticism alive while describing, explaining, or testing phenomena. Research Design: This refers to the specific method used to collect, analyze, and interpret data. Psychologists use three main types of research designs: o Descriptive Research: Describes what is happening at a certain point in time. o Correlational Research: Identifies relationships between variables and predicts future events. o Experimental Research: Manipulates one or more variables to study their effects. Descriptive Research Descriptive research involves studying and recording information about individuals or groups without influencing the situation. Types of descriptive research: • Case Study o Focuses on a small group or individual. o Often used to study unusual or rare situations. o Pros: Provides detailed insight into specific cases. o Cons: Results may not apply to others and can be time-consuming and expensive. • Observations o Naturalistic Observation: Observing behavior in everyday settings (e.g., watching children play on a playground). ▪ Pros: Offers real-world data. ▪ Cons: No control over the environment, and behaviors may not be the same as in real life. • • • • Laboratory Observation: Conducted in a controlled environment. ▪ Pros: More control over variables. ▪ Cons: Participants may act differently because they know they are being watched. Survey o A questionnaire or interview to gather information on beliefs, behaviors, or opinions from a sample group. o Pros: Quick, inexpensive, and can reach many people. o Cons: May not provide deep insights, and respondents may lie or misinterpret questions (social desirability bias). Interviews o Researchers directly ask participants questions, offering opportunities to clarify and dive deeper into responses. o Pros: Provides more detailed, accurate answers compared to surveys. o Cons: Time-consuming and expensive. Psychophysiological Assessment o Records biological data (e.g., heart rate, brain activity) to understand development. o Example: Event-Related Potentials (ERPs)—measuring brain activity using sensors on the scalp. o Pros: Provides insight into the link between biology and behavior. o Cons: Requires specialized equipment and can be complex to interpret. Secondary/Content Analysis o Analyzes pre-existing data, such as documents, media, or public datasets (e.g., U.S. Census Data). o Pros: No need to recruit participants, and large data sets are often available. o Cons: The quality of the data collected in previous studies may vary, and the researcher must understand the original context. Correlational Research 5|Hikamac chi LIFESPAN DEVELOPMENT Correlational research looks at the relationship between two or more variables and measures how they are related. For example, height and weight are correlated because taller people generally weigh more. • Pearson Correlation Coefficient (r) o The Pearson correlation coefficient is a common statistical measure to assess the strength and direction of a relationship between two variables. o The value of r ranges from –1.00 to +1.00: ▪ r = +1.00 means a perfect positive correlation. ▪ r = –1.00 means a perfect negative correlation. ▪ r = 0 means no relationship. o Strength of Relationship: The closer r is to either +1.00 or –1.00, the stronger the relationship. o Direction of Relationship: ▪ Positive Correlation (r > 0): Both variables increase or decrease together (e.g., education and income). ▪ Negative Correlation (r < 0): One variable increases while the other decreases (e.g., the number of diapers a child uses decreases as they age). • Examples: o Positive Correlation: More education generally leads to higher income. The older a child gets, the better they may perform in math. o Negative Correlation: The older a child gets, the fewer diapers they need. More practice often leads to fewer errors on a task. • Limitation of Correlational Research o Cannot Prove Causation: Correlational research can show a relationship, but it doesn’t prove that one variable causes the other. ▪ Example: A study finds that children who watch more violent TV shows tend to play more aggressively. But this doesn't prove that watching violent TV causes aggressive play. ▪ Third Variable Problem: There could be a third variable affecting both variables. For instance, a • • parent's harsh discipline style could influence both the child’s TV-watching habits and aggression. Strengths of Correlational Research o Useful when experimentation is not possible or ethical (e.g., studying harmful behaviors). o Allows researchers to study realworld behaviors in natural settings. o Helps in making predictions (e.g., predicting job success from test scores). Limitations o Does not show cause and effect. For that, researchers need to conduct experimental research. Experimental Research The goal of experimental research is to determine cause-and-effect relationships between variables. It aims to provide more definitive conclusions than correlational research. • Terms o Independent Variable: The variable that is manipulated or changed by the researcher (the cause). o Dependent Variable: The variable that is measured and is expected to be affected by the independent variable (the effect). • How It Works o Experiments are conducted in a controlled setting to test hypotheses (specific statements about the relationship between variables). o Participants are randomly assigned to at least two groups: ▪ Experimental Group: Receives the treatment or condition being studied. ▪ Control Group: Does not receive the treatment and serves as a comparison. o Example: To test if violent TV affects aggression, the experimental group might watch violent TV, and the control group watches a non-violent show. • Controlling Variables o Extraneous Variables: These are unwanted factors that could affect the results. A good experiment controls for these variables to avoid distorting the outcomes. 6|Hikamac chi LIFESPAN DEVELOPMENT • • Strengths of Experimental Research o Allows researchers to determine cause and effect (e.g., does watching violent TV cause aggression?). Limitations o Lab Settings: Experiments are often conducted in a lab, which may not reflect real-life situations. Results might not always apply outside the lab. o Ethical Concerns: Some variables (e.g., abuse, child development) cannot be manipulated for ethical reasons, so experiments are not always possible for these topics. Instead, correlational designs must be used. Research Involving Time-Spans Cross-Sectional Research • What it is: Compares people of different ages at one point in time to study differences in attitudes, skills, or behavior based on age. • Advantages: o Fast and inexpensive since participants are only measured once. o No practice effects (participants don't get better at the task over time). o No need for long-term follow-up. • Disadvantages: o Can't study the effects of being born in a particular time period (cohort effect). o Results may not explain why certain age groups differ in their views or behaviors, as the differences could be due to life experiences, not age. Longitudinal Research • What it is: Follows the same group of people over time to study changes and individual development. • Advantages: o Allows researchers to study development and changes in individuals over time. o Ideal for studying stability and change in people’s behavior or skills. • Disadvantages: o Time-consuming and expensive (requires maintaining contact with participants over a long period). o Attrition: Some participants may drop out over time (move, lose interest, etc.). o Practice effects: Participants may improve on tests simply due to repeated exposure, not actual development. Sequential Research • What it is: Combines elements of both longitudinal and cross-sectional research. It follows different age groups over time to examine age-related changes and possible cohort effects. • Advantages: o Allows researchers to compare changes in the same people over time (like in longitudinal research) and compare different age groups (like in cross-sectional research). o Can provide valuable insights about development in a relatively short period. • Disadvantages: o Requires more time and effort than cross-sectional research, but less than longitudinal research. o Some issues, like practice effects, may still occur, but attrition may be less of a problem compared to longitudinal research because participants aren't studied for as long. Conducting Ethical Research Ethical guidelines are essential to protect the well-being of participants in psychological research, whether human or animal. Researchers must ensure that their studies do not cause harm or undue stress. In the U.S., ethical standards are governed by organizations like the American Psychological Association (APA) and federal guidelines from the Department of Health and Human Services. Ethical Guidelines in Research • No Harm: Researchers must avoid causing harm or distress to participants. • Informed Consent: o Researchers must explain the study's purpose, risks, and 7|Hikamac chi LIFESPAN DEVELOPMENT • • • procedures clearly to participants. o Participants must voluntarily agree to take part and can withdraw at any time. o For children, consent is obtained from parents or legal guardians, and researchers must ensure the child's comfort throughout the study. If the child becomes distressed or tired, the study should be stopped. Confidentiality o The privacy of participants must be maintained. No personal information (like names) should be used in research records. Deception o Sometimes, participants are not fully informed about the study's true purpose before it begins (e.g., hiding the hypothesis or the real aim of the study). o While this is sometimes necessary, researchers must justify why deception is used and make sure it doesn’t cause harm. Debriefing o After the study, participants must be given a full explanation of the study’s purpose and methods. o This is done to help them understand what the study was about and to minimize any negative effects or confusion caused by the research. 8|Hikamac chi