Human Development Chapter 1: Basic Concepts and Methods

Human Development

• Human development is the study of age-related changes in physical bodies, behaviors, cognition, emotions, social interactions, and personalities.
• The field of human development has been influenced by philosophical ideas that continue to shape the field and form the basis for many contemporary beliefs.

Original Sin

• The Christian doctrine of original sin posits that humans are born with a selfish and stubborn disposition.
• According to this view, parents play a crucial role in helping children overcome their innate immoral inclinations by providing guidance and correction.

The Blank Slate

• John Locke's empirical approach suggests that a child's mind is a 'blank slate' and that all differences among individuals are due to their experiences.
• This perspective implies that adults can shape children as they wish, and differences among adults are attributed to their varying childhood environments.

Innate Goodness

• Jean-Jacques Rousseau proposed the view of innate goodness, believing that all humans are naturally good and seek growth experiences.
• According to Rousseau, children only need nurturing and protection to fulfill their potential, and good development occurs when the environment allows a child to nurture their own development without interference.

The Study of Human Development Becomes a Science

• The 19th century marked a significant shift in interest towards applying scientific methods to questions traditionally associated with philosophy.
• By 1930, psychology had established itself as a key contributor to the foundations of modern human development and started influencing daily child-rearing practices.

Darwin

• Charles Darwin and his contemporaries believed that studying child development could shed light on human evolution.
• Darwin's evolutionary theory has significantly influenced modern human development, including the concept of developmental stages.

Development in the Real World

• Toys play a crucial role in children's development, serving as tools that aid their growth and enhance physical, cognitive, and social development.

The Lifespan Perspective

• The field of human development has evolved to cover the entire human lifespan, not just childhood and adolescence.
• Developmentalists now recognize that innate traits interact with environmental factors in intricate ways, and norms are just one of many ways to gauge change.

Research Methods

• Sequential design effectively combines the strengths of cross-sectional and longitudinal studies.
• The National Longitudinal Survey of Children and Youth (NLSCY) is a sequential design study that aims to understand how social and environmental factors impact a child's development across various domains.

Cross-Cultural Research

• Studies comparing cultures or contexts are becoming more prevalent in human development research.

Key Terms

• Experimental group: the group in an experiment that receives the treatment the experimenter thinks will produce a particular effect.
• Human development: the scientific study of age-related changes in our bodies, behavior, thinking, emotions, social relationships, and personalities.
• Independent variable: the presumed causal element in an experiment.
• Interactionist model: the theory that development results from complex reciprocal interactions between multiple personal and environmental factors.
• Lifespan perspective: the current view of developmentalists that changes happen throughout the entire human lifespan and that changes must be interpreted considering the culture and context in which they occur.
• Longitudinal design: a research design in which people in a single group are studied at different times in their lives.
• Maturation: the gradual unfolding of a genetically programmed sequential pattern of change.
• Naturalistic observation: the process of studying people in their normal environments.
• Norms: average ages at which developmental milestones are reached.
• Norm-referenced tests: standardized tests that compare an individual's score to the average score of same-aged peers.
• Physical domain: changes in the size, shape, and characteristics of the body.
• Plasticity: the ability of the brain to change in response to experience.
• Qualitative change: a change in characteristic, kind, or type.
• Quantitative change: a change in amount.
• Research ethics: the guidelines that researchers follow to protect the rights of animals used in research and humans who participate in studies.
• Sensitive period: a span of months or years during which a child may be particularly responsive to specific forms of experience or particularly influenced by their absence.

Behaviour Genetics

• Examines the impact of heredity on individual differences
• Genes influence traits or behaviours, as seen in similarities among relatives
• Research demonstrates heredity's influence on traits and behaviours, including intelligence, altruism, substance use, and hyperactivity

Evolutionary Psychology

• Seeks to explain human behaviour by integrating psychology and life sciences
• Investigates the evolution of inherited cognitive and social traits through natural selection
• Focuses on adaptation of neural networks facilitating cognitive abilities for social relations and interactions
• Prominent proponent Steven Pinker posits that the mind has evolved through natural selection to perform adaptive functions and enhance survival
• Possesses innate patterns of thought and emotion, shaped over time by survival necessities (human nature)

Evolutionary Developmental Psychology

• Argues that a newborn's mind is not a blank slate
• Instead, it is genetically predisposed to learn and develop in specific ways (e.g., learning language and recognizing human faces)
• Each step in development is encouraged by the satisfaction of accomplishing intermediate goals

Learning Principles in Real Life

• Learning principles operate in complex ways in real-life situations
• Partial reinforcement schedules can inadvertently reinforce undesirable behaviours
• Reinforcement can shape behaviours mutually in interactions (e.g., parent-child interactions)
• Reciprocal reinforcement can create patterns that benefit one party but disadvantage the other

Cognitive Theories

• Focus on mental aspects of development, such as logic and memory
• Babies engage in repetitive actions to build their understanding of the world

Erikson's Psychosocial Theory

• Personality develops through eight life crises across the lifespan
• Each crisis results in either a good or poor resolution, influencing personality development
• Important in lifespan psychology, providing a useful description of personality development at different ages

Humanistic

• Emphasizes the basic goodness of human beings and their unique potential
• Focuses on individual choices and personal growth, rather than emotional, biological, or societal forces
• Optimistic, giving people credit for controlling and determining their well-being

Maslow's Theory of Motivation

• Human beings are motivated to satisfy a range of physical, social, and psychological needs
• Ultimate goal is to achieve self-actualization
• Focuses on healthy development

Rogers' Theory of the Self

• Emphasizes the individual's responsibility for personal growth
• Individual can effect change toward personal growth
• Tends to discount the importance of past events

Behavioural

• Behaviour is determined by the environment through conditioning
• Concerned with observable behaviour, not internal mental events
• Learning theories can explain both consistency and changes in behaviour
• Optimistic about the possibility of change, as behaviour can change if the reinforcement system changes

Classical Conditioning

• Learning occurs when neutral stimuli become associated with natural stimuli
• Useful in explaining how emotional responses, such as phobias, are learned

Operant Conditioning Theory

• Development involves behaviour changes shaped by reinforcement and punishment
• Basis of many useful strategies for managing and changing human behaviour
• Ignores hereditary, cognitive, emotional, and social factors in development

Cognitive

• Behaviour can be largely explained by how the mind operates (e.g., memory, thinking, and problem-solving processes)
• Science of cognitive psychology based mainly on laboratory experiments
• Contributed to many effective therapeutic interventions
• Research involves artificial laboratory tasks, which may not fully describe how the mind works in the real world

Fetal Alcohol Syndrome (FAS)

• FAS is a risk for infants of heavy drinkers or those with an alcohol use disorder
• Children with FAS are typically smaller with smaller brains, heart anomalies, and hearing losses
• They often have distinctive facial features such as small, wide-set eyes, a flattened nose, and a thin upper lip
• Intelligence test scores often indicate a mild developmental delay
• Even those without intellectual delays may face learning and behavioral difficulties

Fetal Alcohol Spectrum Disorder (FASD)

• FASD is a term used to describe a range of effects caused by alcohol consumption during pregnancy
• It includes Fetal Alcohol Syndrome (FAS) at one end, characterized by severe effects, and Fetal Alcohol Effects (FAE) at the other, representing milder or partial effects
• A child with FAE may not show physical signs of FAS, but may have secondary issues like mental health problems or learning and behavioral difficulties

Prevalence of FASDs in Canada

• The prevalence of FASDs is approximately 0.5% in the general population
• The prevalence of FAS is about 0.1% in the general population
• However, these rates are estimated to be 16 times and 38 times higher, respectively, among Indigenous populations

Alcohol Consumption during Pregnancy

• About 10% of pregnant women in Canada report alcohol use
• 3% of these women engage in binge drinking and 5% admit to drinking throughout their pregnancy
• The rates are significantly higher among Indigenous women, with 40% consuming alcohol and about 22% binge drinking during pregnancy

Prenatal Malnutrition

• Even moderate drinking can lead to learning and behavioral difficulties in children
• Severe prenatal malnutrition can lead to fetal or newborn death
• Infants with severe prenatal malnutrition have smaller brains and fewer, smaller brain cells
• The adverse effects of prenatal malnutrition can persist throughout the individual's lifespan

Weight Gain during Pregnancy

• Canadian guidelines recommend that a woman with a normal body mass index (BMI) should gain between 11.5 to 16.0 kilograms during a single pregnancy
• Underweight women should gain more, while overweight or obese women should gain less
• Adhering to dietary guidelines is particularly challenging for pregnant Indigenous women in remote communities due to limited access to nutritious food

Food Insecurity

• Pregnant Indigenous women in remote communities have altered consumption patterns, resorting to more rationing and food sharing
• There's been an increased reliance on store-bought food, which often makes healthy options less affordable than calorie-dense, nutrient-poor foods
• Ultra-processed foods now make up over half of the calories in Indigenous diets
• Traditional foods remain a moderate source of protein and essential nutrients, but there's been a shift away from hunting, fishing, and gathering due to increasing costs

Age and Pregnancy

• There's been a trend since the early 1990s of women delaying their first pregnancy until their 30s, accounting for about 43% of firstborns
• Over half of women giving birth in Canada are now 30 or older, and about 22% are 35 or older

Maternal Mental Health

• A mother's emotions can impact prenatal development
• Fetuses of mothers experiencing severe distress, such as anxiety or depression, are more likely to develop emotional, cognitive, or behavioral disorders in childhood and adulthood
• Maternal stress hormones are associated with reduced fetal growth rates
• Providing social support and counseling to stressed and at-risk pregnant women can improve prenatal and infant health and development

Teratogens

• Teratogens fall within three broad categories: mutagenic, environmental, and epimutagenic
• Mutagenic teratogens can cause alterations to genomic DNA
• Environmental teratogens can directly impact prenatal development by damaging cells or disrupting their normal development
• Epimutagenic teratogens account for about 15 to 25% of congenital anomalies, and environmental factors account for another 10%

Maternal Exposure to Pollutants

• Pregnant Indigenous women are particularly concerned about the transfer of heavy metals like mercury, cadmium, arsenic, and lead to the fetus
• Prenatal exposure to these pollutants can lead to preterm birth, low birth weight, and small for gestational age infants, who are at a higher risk of morbidity and multiple adult diseases
• High levels of mercury and lead can impair neurocognitive development in fetuses and children

Location of Birth

• Canadian parents can choose from several childbirth settings: a traditional hospital maternity unit, a hospital-based birth centre, a standalone birth centre, or the comfort of their own home
• In Canada, most births (~97.8%) occur in hospitals
• Home deliveries are considered suitable for uncomplicated pregnancies with adequate prenatal care

Midwives

• Midwifery is a regulated healthcare profession in most parts of Canada
• Midwives are licensed to oversee deliveries and care for newborns
• To become a midwife in Canada, graduation from a recognized midwifery education program is required

Drugs During Labour and Delivery

• Expectant mothers have choices regarding the use of drugs during labour and delivery
• Analgesics can alleviate pain, while sedatives or tranquilizers can lessen anxiety
• Anaesthesia can block pain either entirely or in specific body areas
• The use of labor drugs can increase complication risks and may delay early mother-baby contact

Fetal Development

• Fetus grows from 2 grams and 2.5 cm to 3.2 kg and 50 cm at around 38 weeks
• Organ systems, especially lungs and brain, are refined during this stage
• Viability is achieved by 20-33% of babies by the end of week 22, and increases to 38-58% by the end of week 23
• Survival rate rises to 58-87% by the end of week 24, with additional weeks in the womb enhancing lung function efficiency

Fetal Brain

• Neurons start developing as early as week 3 of the embryonic stage
• Neuronal proliferation accelerates between weeks 10-18 of the fetal stage
• New neurons migrate to their permanent locations in the brain between weeks 13-21
• Synapses form, allowing neural impulses to travel between neurons via neurotransmitters

Sex Differences

• Brain development differs between males and females, contributing to sex differences in cognitive functioning, spatial and verbal abilities, physical aggression, communication skills, and sexual orientation
• Sex differences are also observed in disease patterns later in life
• Females tend to grow more slowly, with distinct growth patterns in boys and girls during the second and third trimesters
• Male fetuses are more responsive to touch, while female fetuses are more responsive to sounds

Prenatal Behaviour

• Fetuses can distinguish between familiar and novel stimuli by the 32nd or 33rd week
• Newborns seem to remember prenatal stimuli, such as their mother's heartbeat, the smell of amniotic fluid, and stories or music heard in the womb

Illicit Drugs

• Heroin and methadone use during pregnancy can lead to miscarriage, premature labor, and early death
• 60-80% of babies born to heroin-addicted mothers are also addicted, experiencing withdrawal symptoms
• Cocaine use is linked to developmental issues in children, but it's challenging to isolate the effects of cocaine from other factors
• Cocaine can cause pregnancy complications like placental disruption and premature labor

Environmental Teratogens

• Environmental agents can directly impact prenatal development by damaging cells or disrupting their normal development
• These agents can interfere with cell proliferation, migration, and differentiation, leading to congenital anomalies and structural and functional abnormalities
• Pregnant Indigenous women are particularly concerned about the transfer of heavy metals like mercury, cadmium, arsenic, and lead to the fetus
• Prenatal exposure to these pollutants can lead to preterm birth, low birth weight, and small for gestational age infants

Epimutagenic Teratogens

• Mutagens causing direct cell damage account for about 15-25% of congenital anomalies, and environmental factors account for another 10%
• Scientists suspect that a large proportion of these "unknown" factors may be epigenetic

Neonatal Assessment

• The Apgar score is used to assess a newborn's condition, with a score of 7 or above indicating a safe condition
• Standard screening procedures in Canada now include the detection of rare metabolic disorders in newborns
• The Brazelton Neonatal Behavioral Assessment Scale is used to monitor a newborn's development during the first couple of weeks after birth

Low Birth Weight

• Neonates weighing less than 2500 grams are categorized as having low birth weight (LBW)
• LBW infants have higher hospitalization rates and an increased incidence of illness and mortality
• Most LBW infants are preterm, but it's possible for a baby to complete 38 or more weeks of gestation and still be classified as LBW

Evolutionary Developmental Psychology

• Theorists propose that both nature (genes) and nurture (environment) play a role in shaping an individual's intelligence, personality, and social behavior.
• Different stages of life require different behavioral responses, and evolutionary forces have led to the development of age-specific strategies that enhance survival and adaptation throughout a person's life.

Evolutionary Prenatal Programming and Adult Health and Disease

• The risk of non-communicable diseases like heart disease, diabetes, and obesity may be influenced by early life factors, such as environmental cues received by the fetus from its mother.
• These cues can lead to epigenetic changes that aid in survival, but a mismatch between the prenatal and postnatal environments can contribute to lifestyle-related diseases in adulthood.
• The greater the mismatch, the higher the risk of disease.

Applying Biological and Evolutionary Theories

• Biological principles, such as genetics and epigenetics, are expanding our understanding of disease processes and the importance of early intervention.
• Advancements in human genomics are expected to contribute significantly to disease prediction and prevention, particularly for multifactorial diseases like heart disease and cancer.

Learning Theories

Operant Conditioning

• Operant conditioning is a type of learning where behaviors are influenced by their consequences, such as reinforcement or punishment.
• Positive reinforcement involves adding a pleasant consequence after a behavior, increasing the likelihood of its repetition.
• Negative reinforcement involves removing an unpleasant condition following a behavior, also increasing the likelihood of its repetition.
• Punishment can be in the form of negative punishment (removing something pleasant) or positive punishment (introducing an unpleasant consequence).

Shaping and Partial Reinforcement

• Shaping involves reinforcing incremental steps to teach a complex behavior.
• Partial reinforcement, where a behavior is reinforced only sometimes, is more common in real-world scenarios and can lead to behaviors that are highly resistant to extinction.

Key Concepts

• Behavioral epigenetics: the study of how the environment and personal behavior can cause epigenetic changes that affect gene expression, resulting in changes to behavior and psychological processes over the course of a life and across generations.
• Bioecological systems theory: Bronfenbrenner's theory that explains development in terms of the relationships among individuals and their environments, or interconnected contexts.
• Chromosomes: strings of genetic material in the nuclei of cells.
• Classical conditioning: learning that results from the association of stimuli.
• Cognitive theories: theories that emphasize mental processes in development, such as logic and memory.
• Deoxyribonucleic acid (DNA): a chemical material that makes up chromosomes and genes.
• Epigenetics: the study of the gene regulation patterns that alter gene function (phenotype) without changing gene structure (genotype).
• Epigenome: the sum of inherited and acquired molecular modifications to the genome that leads to changes in gene regulation without changing the DNA sequence of the genome.

Human Development

• Human development is a field of study that examines age-related changes in physical bodies, behaviors, cognition, emotions, social interactions, and personalities.
• This field has been influenced by philosophers who provided various explanations for the differences they noticed among individuals of varying ages.

Philosophical Influences

• Original Sin: The Christian doctrine of original sin posits that humans are born with a selfish and stubborn disposition, and that parents play a crucial role in helping children overcome their innate immoral inclinations.
• The Blank Slate: John Locke's empiricist approach suggests that a child's mind is a 'blank slate', and that all differences among individuals are due to their experiences.
• Innate Goodness: Jean-Jacques Rousseau proposed the view of innate goodness, which suggests that humans are born with a natural inclination towards good.

Early Developmental Researchers

• Stanley Hall: Hall conducted the first scientific study of child development, using questionnaires and interviews to research numerous children. He proposed that developmentalists should establish norms, or average ages, for reaching developmental milestones.
• Arnold Gesell: Gesell's research proposed a genetically programmed sequence of change, termed 'maturation', which occurs irrespective of practice, training, or effort.
• Jean Piaget: Piaget is renowned for his influential theories in human development, including the idea that humans follow a genetically determined plan, and that universal changes are due to shared experiences.

Cultural and Social Influences

• Social Clock: A social clock, which varies by culture, shapes lives into common patterns of change, outlining the sequence of typical life experiences.
• Ageism: Ageism is a form of prejudice against older adults, which can lead to older adults being overlooked for work opportunities due to the assumption that they are less competent than their younger counterparts.
• Cultural Influences: Culture influences individual development, shapes our perceptions of what constitutes normal development, and affects our understanding of phenomena like retirement.

Research Methods

• Group-Specific Changes: Group-specific changes are common to all members of a particular group, with culture being a significant group.
• Experiments: Experiments are crucial for understanding various aspects of development, but there are limitations in studying child or adult development.
• Independent and Dependent Variables: In an experiment, the independent variable is the factor presumed to cause an effect, and the dependent variable is the characteristic or behavior it is expected to influence.
• Random Assignment: Random assignment is a crucial aspect of an experiment, ensuring that group placement is determined by chance, and that variables cannot influence the experiment's outcome.

Ethics and Key Terms

• Knowledge of Results: Participants, their parents, and the administrators of institutions have a right to a written summary of a study's results.
• Deception: Deception may be required in research studies to prevent participant expectations from influencing behavior, but it must not cause distress to participants, and they have the right to be informed about the deception immediately after the study concludes.
• Ageism: a prejudicial view of older adults that characterizes them in negative ways.
• Atypical Development: development that deviates from the typical developmental pathway.
• Case Study: an in-depth examination of a single individual.
• Cognitive Domain: changes in thinking, memory, problem-solving, and other intellectual skills.
• Cohort: a group of individuals who share the same historical experiences at the same times in their lives.
• Control Group: the group in an experiment that receives either no special treatment or a neutral treatment.
• Correlation: a relationship between two variables that can be expressed as a number ranging from -1.00 to +1.00.
• Critical Period: a specific period in development when an organism is especially sensitive to the presence (or absence) of some particular kind of experience.
• Cross-Sectional Design: a research design in which groups of different ages are compared.
• Dependent Variable: the characteristic or behavior that is expected to be affected by the independent variable.
• Ethnography: a detailed description of a single culture or context.
• Experiment: a study that tests a causal hypothesis.