Human Development: Key Questions

Key Questions in Studying Human Development

• Developmental psychology examines physical, cognitive, social, and emotional changes from infancy through old age.
• Developmental psychologists seek to answer the nature of psychological change across the lifespan.
• Understanding if development occurs in distinct stages or is a continuous process is important.
• Stages involve distinct segments of life with sharp differences; the difference between a tadpole and a frog is distinct, not gradual.
• Stages describe how people change and how people across different ages are similar.
• In intellectual development stages, children benefit from similar educational experiences and classroom settings.
• Qualitative development involves abrupt psychological changes from one stage to the next.
• Quantitative development entails gradual and continuous changes over time.
• Examining the effects of nature and nurture on development is crucial.
• Maturation is a series of genetically determined biological processes enabling orderly growth, relatively independently of experience.

Tools for Studying Development

• Psychologists face challenges when studying development, including age-specific measures and research methods for lifespan comparisons.
• Cross-sectional design compares participants of different age groups to study development.
• Understand abilities developing at certain points in the lifespan, like comparing 12-month-olds to 6-month-olds
• Cohort effect is an effect due to shared life experiences within an age group.
• The cohort effect is a key disadvantage of cross-sectional research designs.
• Longitudinal design tracks participants over time, comparing each at different time points
• An example of longitudinal tracking example is tracking infants from 6 to 12 months or tracking 20-year-olds across decades.
• Disadvantage 1: requires time and resources, especially for exploring large life segments.
• Attrition is a disadvantage: participants withdrawing before the study is finished.
• Examining a single generation or cohort may limit the generalizability of results.
• Sequential design tracks participants across time and compares different age groups and individuals to themselves at different time points.
• Comparing reading comprehension of 40 and 50-year-olds and retesting in 10 years can reveal age-related changes.
• This method offers high confidence that observed changes are due to developmental rather than cohort effects.
• Conducting sequential design is considerably costly and time consuming.

The Start of the Journey

• A mature egg is released from an ovary.
• A sperm fertilizes the egg by releasing enzymes to pierce its protective coating.
• The egg blocks other sperm after one penetrates its defenses.
• The nuclei of the egg and sperm fuse into a zygote, combining genetic material into 23 pairs of chromosomes.
• 23 pairs of chromosomes provide a unique blueprint for a new human individual.
• The germinal stage is the first two weeks of a zygote's life.
• During this stage, the cells of the zygote multiply rapidly.
• Two weeks post-conception, the cell ball, or blastocyst, implants in the uterus.
• Over half of all zygotes fail to implant and are flushed out of the body.
• The embryonic state starts for surviving zygotes after 2-8 weeks.
• The inner cells of the blastocyst form the embryo (an unborn, developing offspring, identified in humans between the 2nd and 8th week of pregnancy).
• The placenta begins to form where the blastocyst's outermost cells meet the wall of the uterus.
• The placenta is a collaboration between the pregnant person and the embryo.
• It is made from their tissues and acts as a channel between them.
• The placenta transports nutrients and oxygen from parent to offspring, and removes waste.
• Embryo cells differentiate and organize into three layers that become different body parts.
• Endoderm layer: forms the gut and digestive organs.
• Mesoderm layer: forms the skeletal system and voluntary muscles.
• Ectoderm layer: becomes the cells of the nervous system and outer skin.
• During the embryonic stage, about a month after conception, the neural tube develops from the ectoderm layer.
• The neural tube is a tubular structure formed early in the embryonic stage from which the brain and spinal cord develop
• The neural tube develops into the spinal cord and brainstem, the midbrain, and the forebrain.
• The cells of the developing brain are either neurons or glia.
• Neurons and glia start to become distinct and work together to reproduce.
• Through neural migration, glia functions as guide wires that move newly created neurons to appropriate brain positions.
• Chemicals surrounding the neurons guide the migration, direction, and placement.
• Neurons migrate and organize themselves into layers, following an inside-out pattern.
• The first-arriving neurons become the innermost layer of the cortex.
• Later-arriving neurons pass these cells to form the next layer and are passed by later arrival.
• Genes determine neuron migration and help the brain wire itself appropriately.
• By the end of the 6-week embryonic stage (8 weeks after conception), differentiated cells begin to form organs that start to function.
• The embryo becomes recognizable as human, with an oversized head, facial features, arms, and legs.
• The fetal stage follows the embryonic stage, beginning in the 9th week until birth.
• A fetus' sensory systems start gathering information from the world.
• By the 17th week, the fetus' ears begin to function and respond to sounds.
• The most distinctive sound heard was the pregnant parent's voice, transmitted from both outside and through the parent's body.
• The fetus' eyes remain closed until the 26th week but respond to light with increased heart rate.
• At 37 weeks, a fetus is considered full-term, with developed brain, lungs, and liver for life outside the womb.
• Babies are usually born 38 weeks after conception.

Variations in Early Development

• Down syndrome is a developmental disorder caused by an extra copy of chromosome 21 from either the egg or sperm.
• Down syndrome is characterized by intellectual disabilities, delays in motor development, and increased health problem risk.
• Down syndrome affects 1 out of every 691 babies born each year in the United States.
• Teratogens are environmental agents that can interfere with typical development and may slip through the placenta.
• The placenta actively prevents many potentially harmful viruses, drugs, and toxins from reaching the developing fetus.
• Examples of Teratogens include: Lead, Mercury, Carbon monoxide (such as from car exhaust), Some pesticides, Alcohol, Cigarette smoke, X-rays, Rubella and Viruses.
• Fetal Alcohol Syndrome is a developmental disorder affecting children exposed to alcohol during prenatal development.
• Fetal Alcohol Syndrome includes a range of learning and behavioral challenges as well as differences in physical size and facial characteristics.
• Fetal Alcohol Syndrome is the result of heavy drinking.
• Consuming alcohol while pregnant can increase the likelihood that the offspring will find alcohol appealing.
• Some teratogens affect brain development and increase the risk of psychological disorders later in life.
• Prenatal exposure to the influenza virus increases the likelihood of developing schizophrenia.
• Prenatal exposure to the pregnant parent's smoking, drinking, and marijuana use is associated with later symptoms of ADHD.
• Teratogens increase later risk for psychological disorders through their effects on the immune system.
• Microglia produces molecules within the central nervous system and plays a crucial role in brain development.
• Early immune system activity in pregnant person or fetus can disrupt microglia functioning and causes long lasting effects in the brain.
• Immune system activity can be caused by a virus, reactions to stress or to environmental toxins
• Pregnant individuals from lower income and marginalized backgrounds have less access to good nutrition and medical care.
• Individuals from lower income may also have more exposure to environmental toxins.
• This puts fetuses at greater risk for atypical development and preterm birth.
• Improving the health of all developing fetuses involves prenatal access to necessary resources.

Early Capabilities in the Newborn

• Newborns are equipped with reflexes that help them survive, connect with others, and learn.
• Reflexes are automatic patterns of motor responses triggered by sensory stimulation.
• Reflexes help newborns obtain food by guiding the newborn toward a nipple upon cheek stimulation.
• The newborn will automatically close their mouth and suck when a nipple is found.
• Reflexes help newborns grasp and explore their environment for example, placing a finger in a newborn's palm will cause them to gasp it.
• Reflexes also provide a window into newborns' mental abilities and sucking reflexes offer insight into what infant learned in the womb.
• Infants can learn and distinguish their pregnant parent's voice from other voices.
• Newborns are born with some limited control over their eye, head, and facial movements.
• Newborns prefer to look at objects 8 to 12 inches away, which is the typical distance between a feeding infant's eyes and its caregiver's face.
• Habituation is a simple learning form involving a decreased response to repeated stimuli.
• Dishabituation is an increase in responsiveness to something novel after habituation.
• The Novelty-preference procedure tests habituation by showing infants a stimulus until looking time decreases.
• Then the researcher presents the same stimulus again or a new one.
• Newborns tend to show little interest in the old stimulus but dishabituate to the new one with renewed interest in looking.
• These studies show that newborns perceive and store simple visual patterns and respond to changes in their immediate environment.
• Babies are capable of learning while still in the womb.

Emerging Motor Skills

• Motor development involves changes in the ability to coordinate and perform bodily movements.
• Infants' motor skills develop according to two general rules:
• Motor skills emerge in sequence from head to feet, gaining head control before the ability to run.
• Motor skills emerge from the center of the body outward, requiring core muscle strength before fine motor actions.
• Genetics play a major role in the timing of motor development.
• Identical twins show extremely parallel motor development, often beginning to sit or walk on nearly the same day.
• Infants develop their own strategies to solve the problem of getting from point A to point B, which cause different crawling styles to emerge.
• Babies born in the summer start crawling later because they have to wear heavier winter clothes.
• Slow motor development is associated with reduced risk of SIDS but delayed motor milestones.
• Slow motor development is common in cultures where children sleeping on their backs and development can be helped with "tummy time”.

How Thinking Changes: Piaget's Theory

• Cognitive development: changes in all of the mental activities associated with thinking, knowing, remembering, and communicating.
• Jean Piaget argued that cognitive development is active and mostly self-driven.
• Schemas: units of knowledge that represent our experiences and are used to guide how we interpret new information.
• Understanding comes in the form of schemas that capture knowledge types about the world, e.g sensations, actions, objects, events, roles.
• Newborns start life with schemas related to built-in reflexes, like sucking or grasping.
• According to Piaget, assimilation uses an existing schema to interpret a new experience.
• A child may correctly call a Chihuahua a "dog", knowing the dog label applies to four-legged animals that bark.
• Accommodation revises existing schemas to incorporate new information from a new experience.
• The child broadens their dog schema when they see a new example and dog differs from other examples of dogs they have seen before.
• Piaget argued that children's thinking goes through bursts of change followed by stability, moving through four distinct and universal cognitive stages in sequence:
• Sensorimotor Stage (birth to 2 years): Children develop knowledge through senses and actions and can't think using symbols or language.
• During the sensorimotor stage, children learn object permanence
• Preoperational Stage (2 - 7 years): Children master the use of symbols but struggle to see situations from multiple perspectives.
• Concrete Operational Stage (7 to 12 years): Children can use multiple perspectives and their imagination to solve complex problems, but only on solid objects or events.
• During the concrete operational stage, children can think logically about concrete objects in terms of numbers, mass and weight.
• Formal Operational Stage (12 years and up): Adolescents can reason about abstract problems and hypothetical propositions.
• The stage of formal operations is where they can become concerned with the possible as well as the real.
• Piagen viewed children as self-driven learners.

Learning About Objects - The Role of the Developing Brain

• Object Permanence: the awareness that objects continue to exist even when those objects are temporarily out of sight.
• Before the age of 8 months, babies typically fail to search for the hidden object, staring nonchalantly at their parents
• Violation-of-expectation method: takes advantage of the fact that babies are surprised by things they don't expect.
• When their expectations are violated, infants tend to stare at the unexpected object or event.
• Research show infants look longer at events violating natural laws, like objects disappearing
• The infant's nervous system needs to organize itself into complex and efficient neural networks to support thinking, feeling, and behaving.
• Neural proliferation: the creation of new synaptic connections.
• Synaptic pruning: the trimming back of unnecessary synapses according to a "use it or lose it" principle
• Myelination of axons: the process of insulating axons in myelin, which speeds their conductivity.
• The slowest areas to mature in children's brains are those in the frontal lobe, which enable rational planning

Early Social and Emotional Understanding

• Infants seek out human faces from birth and gradually learn how to “read” the behaviors of other people as they look at a face and respond to it.
• Between 4 and 7 months, infants distinguish happy, sad, and angry facial and vocal expressions, especially if familiar with the faces of their caregiver.
• Social Referencing is the reliance on the facial expression of a caregiver as information for how to react.
• Infants quickly learn which behaviors predict others.
• Over the first year, infants develop some ability to infer the intentions that underlie the behaviors they observe, as an early step in understanding people's behaviors.

First Love - Forming Attachment

• Children begin forming their first social relationship with a primary caregiver, usually a parent.
• Young infants seek closeness from caregivers and show distress when separated which is know as separation anxiety and emerges between 6-8 months old.
• Attachment: The strong, enduring, and emotional bond between an infant and caregiver.
• Imprinting: A mechanism for attachment early in life that follows the rule of attaching to the first moving object an organism sees.
• Lorenz discovered that ducklings approach and follow the first moving stimulus it sees, typically its mother, from approximately 12 hours after hatching.
• The duckling is now imprinted, will continue to follow it and show distress when separated or threatened.
• In nature, nourishment and contact comfort occur at the same time, making it difficult to tell which is more important to shaping attachment.
• Social deprivation are devastating to humans and can cause delays in physical, motor, cognitive, and social development.

Individual Differences in Attachment

• Strange Situation Test (Ainsworth): child & caregiver enter unfamiliar environment filled with toys.The child explores & plays in while the caregiver remains. A stranger then enters & leaves the child alone. The caregiver returns moments later.
• Ainsworth says children's attachment styles are classified as either secure or insecure
• Secure Attachment style: use caregiver as a secure base, explore and play, even make overtures to stranger but only when caregiver is present
• Secure attachment: show minor distress when caregiver leaves but show enthusiasm when caregiver returns/ quickly reassured
• Roughly 60% of healthy/ middle-class families in North America are securely attached
• Secure attachment: most common attachment style observed across cultures and promote social skills.
• Secure attachment: show fewer behavioral problems/ anxiety disorders in childhood/ adolescence
• Insecure attachment: no reassurance after separation. 2 types:
• Insecure/ avoidant attachment style - 15% of children, healthy, middle class North American. - Act aloof/distant with present caregiver although look for caregiver when goes absent but ignore caregiver on return. - Although infants look unruffled on surface, apparent calmness: mask for distress - heart rates increase when parents leave/ remain high when return.
  • Likelihood increase in cultures of independence, i.e. North America/ Western Europe
• Insecure/ ambivalent attachment - 10% of children, healthy ,middle class North American. - Do not explore even when caregiver is present as upset when leave. - On reunion, act ambivalent- cry/ run to be picked up and kick/ struggle to get down.
  • Likelihood increase in cultures of independence, i.e. Asia
• Temperament: characteristic pattern of emotion/ behavior that is evident from early age/ believed to be genetically determined.
  • Irritable infants tend= upset more/ difficult to soothe, higher likelihood of developing insecure attachment.

Getting Savvy With Symbols

• Childhood: period ending infancy (roughly age 2), starts adolescence
• symbolic representation: use of words, sounds, gestures, images, etc. other things.
• Capability for symbolic representation begins in early childhood, during the preoperational stage, which lasts from age 2 to age 6-7.
  • i.e. acquire symbolic schemas.
  • Piaget: imaginative plays: indication of children symbolic schemas: i.e motivation+ capacity to pretend to emerge spontaneously during the preoperational period.
• i.e. Using symbols requires ignoring thing's literalness to know present meaning. Taking time/ practice to make connection
• 2 1/2 yr old children have trouble locating toy after scale placement.
  • i.e researchers improved kids performance because placed the model out of reach behind a glass partition remote, less toylike, to see something else.

Reasoning About the Physical World

• Operations: in childhood schemas. - Kids: symbolize by schemes during preoperational period, struggle to manage multiple schemas at same time/ recognize schemas relate to each other. - i.e. difficulty thinking of flower as both multi-colored + rose at same time.
  • Operations: ability to imagine how things/ objects may differ+ consequences of event without seeing happen.
  • Young kids struggle/ reason for physical problems with operational abilities missing
• Conservation: physical object- mass, volume+ number- same despite shape transformations
  • Piaget: preoperational children dont understand principles of conservation because not understand/ relate different dimensions of the situation.
  • Conservation tasks: difficult for young children, due connection to prefrontal lobe+ brain structures

Mastering a Sense of Self and Other Minds

• Young infants behave in ways separate from others, meaning lack sense of self - but cultures influence greatly through imitation.
• Mirror recognition and others emotions = better ability to show concern for others' emotions, to console a peer.
• Piaget: Children have trouble perceiving from point of view during preoperational period- called Egocentrism: i.e difficulty perceiving situation ii. i.e hide under bed not knowing someone see their legs iii. i.e constant spot despite predictability.
• Theory of Mind relates what people have and show other minds, represent world ways, explain/ predict how those behaviors change.
  • Young people: lack theory of mind - i.e False- belief Doll test: a child does not understand that marble hides another fake marble.
  • 18-month-old: kids think people vary what they like based on specific tastes
  • Task: understanding others+ how predict behavior

A Little Help, Please? Learning From the Social World

• Sociocultural view (Lev Vygotsky): a child's mind increases from interaction through active/ knowledgeable environment.
• Scaffolding: to increase cognitive dev through things beyond their capabilities+ support.
• Scaffolding: mentoring+ better when challenges child but no overwhelm
• I.e Language Scaffolding: listen+ repeat during private time to promote mental support via adults over others minds, desires, interests.
• Researchers: when frequent mental-state in language usage, infants pass false belief. Autobiographical memory: memorize one’s life events.
  • The ability of events grow with conversation
  • kids capacity grows as questions are asked in conversation i.e. elephants in school, more broadly to whats happening?
  • In same way if parents differ more or less they build with what you share and those affect memory.
    • Conversations with moms about events may help with childhood events.

Gender Development in Childhood

• Infant's biological sex immediately evokes expectations about gender identity/ characteristics.
• Gender identity: a psychological id of gender. (male, female, nonbinary)
  • New babies do not have selves/ genders just yet but often have genders.
    • Cisgender: to gender id matching born sex to stereotypes.
• Analysis if congrats card in new parents reveal if gender use words like sweet, dear in girls while bold, brave in boys .
• Gender Socialization: process for social expectations and attitudes when internalizing their gender..
  • Comes from media+ toys offered.
• E.g- given togirls emphaize on nurture , domestic, appearane while marketed to boys: violence+ comp.
• Parent roles: major role in gender socialization
  • expect girls do fam chores caring+ cooking while boys do yard/ take out trash
  • fathers give sons risks over daughters, mothers underestimate daughters. Gender Schema: Network if assumption about gender think and act like..
  • 3 y/o group people as girls, boys, men, women.
    • Same, kids get self id, claim own gender in binary i. e "boy or girl"

More about gender..

• Preschool 3 - 5: kids develop a good stereotypical on gender expectations + ways.

• E.g.: doll = 2 yr + truck .

• Different ethnic groups where kids this more/ less play exclusively or play with peer.

• Young kids have very rigid sterotypes leading small gender police” in judgment when act out, i.e gender activities are girls+ vice versa.

  • Views rigid with both genders, but can find selection based gender-identity for biological-related ones..

• Elemen try: kids, have more flexible understanding of gender. -Gender Constancy: is gender consistent + how act, dress, what born as.

  • Helps loosen the rigidities and help girls reject, identify as “tomboys".

• Boys greatly conform, pressures from other, those do don't/ experience is social rejection.

  • Elements of gender stereotypes are internal and internalizing while knowing more higher, reward than femme.

• Like gender differences: roles why are boys more rejected when they feel bad/ not rin+ tend see goodness/ Kindness rather be it with better thing.

Parenting Styles: What to blame/ credit

• 2D of styles: 1- Sensitive/ responsive when acts on wants and needs

  • 2- Demanding+ controlling behavior when needs. Four: see a range Authoritarian : min emot + strict - ex obedience + respect.
    • No follows= severe punish Permissive : High sens/ low demand scale" unstructured and few rules + punishment and chores - lead with low attention in schedule. Authoritative: very responsive, demanding
  • Set clear rules+ structure - and understand
    • flex Responds kids opinions i. e bend circumstances, understand and give support/ responsibilities Disengaged : neither , responsive and demanding.

• Neglt/ insensitive + disengages when concern with childrearing in neglect and neglect.

• Is one parenting best? - Earliest research find which styles find best- self control. curious, happy

  • Authority, predicts high academic, adaptation, solve+ health body

• What other styles predict: A: Obedient towards adults academic worst. P: high self but low control.

  • Deny: low academics/ health behavior like smoking

• children respond to being supportive+ responsive demanding

• How it matters how parent shape how their kid show children.

  • Subborn elicits more demanding and logical child responsive

Changing Body and Brains

• Transitional period and puberty in sexual and adult reproduction cycle -Involves Chain hormones + Sex: primary sex where ovaries, testes or genitalia in reproduction.. - Secondaries: hair in hips voice - Avg is start period at 11 +males late at 13.. critical measure menstruation , 12, ejaculation, age, puberty: -Genetics impacts Puberty: if twin have the same or same time as age parent started.

• High in body for better than fat and fat gain for for early. Puberty=

  • Advantages for boys can be better, stronger, more social by puberty/ sports and social circle more impulse than girls- also increase deliquesce + alcohol Early is risky+ anxiety: Bodies can make less welcome where fit in more and can be seen from older boys in better home +neighborhood+ support. With bodies growing during puberty may have sex intensification - with that can be stereo +homo and bad behavior/ rejection-

• Rapid change in the brain+ body both: synaptic grows with that, also need better control in the brain or better long term.

• Brains:

  • The rev up reward system to reward adolescence. The reward to activities: greater with social act with attractive or social-not overload/implusions..

Advancing in Reasoning.

• Formal in: ad. 12 - ability in reas abstract+hypothetical

  • The better in with reason math +science skills. Can be applied/reason with relation society:
    • 1 - Envision in relations for new society. 2-Inconsistencies by Hypo. 3- Challenge + adapt 4. Not how world but could be

• More Reasoning+ Perspec: with Moral situations- through L. K moral.

  • Stories of the moral questions+ answers for how moral should work

• K moral: Reason with through sequential 3stages level:

  • A: Before age 9 Kohlberg's theory" moral judgments by rewards + such as bad" you are in trouble.

• B. Conventional:"  caring and roles- might be bad because hurt- or simply bad"
  

• C: post convention." bad hurt life bad- is bad if bad prevents freedom" 1 - views may wrong because hold societies prevents bad chaos .

• Argument that Kohlberg, done the best over women.

• Views sees that women care+ prevent roles. - In women moral put them at lower scale.

• asked to reason- with kohlberg, low due less.

  • Often concrete factors /wife concern due +moral with Justice -moral

An Evolving Senses

• E, E first to view argue through for identity." Lifelong 8 stage by dev stage."
• Stage= develop task and psych crisis "i/d - mother- is M to Trust" E childhood. Controlling Self doubt is Autonomy= direct/pupose:Initiative- physical competence inferiority. making identity adolescence:identity.love -friendship Intimacy/ Generativity vs stagnant and vs despair vs meaning

The of ad: view for self and for views in one person. We view all ourselves through who we are at head, social is identity as one social groups. Ethnic is racial identity ethnic, strong.

• As time, gets less parents- in is. As time accepted as by peers+ reject = greater motivation crowd
• part: is fit in skills

End of Part #3

• Adolescentes get great group of others becasue are liked + the time to no influence to follow. the fMR1 show show the others grow + caused with reasons,orgs,growth
• ad =period of life with end from finish school independence
• J.A: emerged adulthood +expect the great in a +work
  • feeling found young -fuzzy gradually better

Social Role Marriages

• Social: clock: milestones = time when deviate + stress the important/late Erikson;s ad dominated task: greaty
• Psycho: Intamicy with stages
  • i) Eric: build romantic and marrirage.
  • ii) On live money
  • iii) Before married increase happy

-iv) Countries importance

• Psycho Generosity to contr - - positive good
• having kids90 %
• States Asian high
• desire evolutionary
• puts damp -dad reports. Positive and non= non . Better
• exp.
• High and lower

• boost great in woman for
• --change time on great burden black to - woman care and not the .
• increase chose is birth less at i jobs for delay

Changing and late adulthood

• good and + better against
  • decrease and and decline. less. ---adults dev + long more but more preserve.