Human Development

human development

the examination of continuity and change across the lifespan

prenatal development

the period of time prior to birth

teratogen

a chemical agent that can harm the zygote, embryo, or fetus

• exerts most negative effects during embryo period

embryo

developing organism gestational weeks 3-8

zygote

developing organism gestational weeks 0-2

fetus

developing organism gestational weeks 8-birth

assimilation

incorporation of new learning into an existing schema without the need to revise the schema

fetal alcohol spectrum disorder (FASD)

a group of conditions that can occur in an individual when a mother consumes alcohol during pregnancy
effects include physical abnormalities and cognitive and behavioural problems

pruning

process in which unused or unnecessary neurons and synapses are eliminated in order to enable more efficient neural processing

accommodation

the incorporation of new learning into an existing schema that requires revision of the schema

sensorimotor stage

Jean Piaget’s stage of development (0-2 years)

• rely on movement and senses to explore environment

• develops object permanence

equilibration

process by which a child engages in assimilation and accommodation in order to make sense of the world

circular reactions

repetitive actions observed in children during the sensorimotor stage of cognitive development

conservation

the ability to understand that changing the form or appearance of an object does not change its quantity

preoperational stage

Jean Piaget’s stage of development (2-6 years)

• use of symbols, egocentrism, and limits on the ability to reason logically

• language acquisition

• passing conservation tasks

• move from egocentrism to sociocentrism

  • developing a working TOM

egocentrism

limitations on the ability to understand the point of view of other people

object permanence

the ability to form mental representations of objects that are no longer present

concrete operational stage

Jean Piaget’s stage of development (6-12 years)

• logical but not abstract reasoning

• mastery of conservation problems

• learning by doing (hands-on)

formal operational stage

Jean Piaget’s stage of development (12-adulthood)

• mature/abstract reasoning capabilities

• idealism

zone of proximal development

in Vygotsky’s theory, tasks that the child can accomplish with the assistance of more experienced or knowledgeable individuals

attachment

emotional bond linking an infant to a parent or caregiver

theory of mind (TOM)

the understanding that others have thoughts that are different from one’s own

• measure through False Belief Test (change of location task or unexpected contents task)

secure attachment

a pattern of infant-caregiver bonding in which children explore confidently and return to the parent or caregiver for reassurance

insecure attachment

a pattern of infant-caregiver bonding that can take several forms but is generally characterized as less desirable for the child’s outcomes than secure attachment

adolescence

a period of development beginning at puberty and ending at young adulthood

conventional morality

Lawrence Kohlberg’s stage of moral development in which moral choices are made according to law or public opinion

puberty

a period of physical changes leading to sexual maturity

secondary sex characteristics

physical changes occurring at puberty associated with sexual maturity

preconventional morality

Lawrence Kohlberg’s stage at which moral choices are made according to expectations of reward or punishment

postconventional morality

Lawrence Kohlberg’s stage at which moral choices are made according to personal standards and reason

identity

a consistent, unified sense of self

menopause

the complete cessation of a woman’s menstrual cycles

main periods of human development

1. prenatal period & infancy (conception -2-3 years)

2. childhood (2-3 - 11 years)

3. adolescence (12-25 years)

4. adulthood (25 years - death)

stages of prenatal development

1. germinal stage / period of the zygote (0-2 weeks gestation)

2. embryonic stage (3-8 weeks)

3. fetal stage (9 weeks - birth)

germinal stage (0-2 weeks gestation)

• fertilization occurs when a sperm meets an egg in the fallopian tube during ovulation

• once egg is fertilized, germinal stage begins

• period of rapid cell division - ends when the blastocyst implants into the wall of the uterus

embryonic stage (3-8 weeks gestation)

• begins when the blastocyst implants into the wall of the uterus

• period of growth for major bodily structures

• by end - all major bodily structures are formed but embryo cannot yet survive outside of uterine environment

fetal stage (9 weeks gestation - birth)

• period of refinements and finishing touches; significant growth

• sensory abilities start to come online (when learning starts)

• significant advances in brain development: (week 22-birth)

  • neurogenesis (forming of new neurons)

  • myelination (helps transfer signals in brain and between neurons)

  • synaptogenesis (point of contact between two neurons)

  • synaptic pruning (remove/delete connections that aren’t needed

examples of teratogens

• alcohol

• thalidomide - used during 1960s to prevent morning sickness

• zika virus - microcephaly in infants (small heads)

longitudinal research design

same individual over time

cross-sectional research design

at one point in time, but different age groups and multiple individuals

high amplitude sucking paradigm

uses sucking frequency to measure preferences

habituation paradigms

• examines whether infants can discriminate between 2 stimuli

• involves repeatedly showing an infant one stimulus over and over until they are “bored with it, then a new stimulus is shown

• if an infant dishabituates (and displays increased looking time) to the new stimulus, it suggests that the infant was able to discriminate between old and new stimulus

sensation

sensory organs’ detection of physical signals in the environment

perception

organization and interpretation of the sensory information into coherent understanding of objects, individuals, and events

preferential looking

infants choose to spend more time looking at things that are interesting

the grating visual acuity test

used to measure visual acuity in infants

• within first month after birth, infant’s visual acuity goes from 20/400 to 20/120

• adult like acuity by 6 months

• color and depth perception development in first 6 months

newborn motor development

mainly reflexes:

• grasping

• rooting (orient face toward a stimulus)

• sucking

• tonic neck reflex (extend arm to same side of head)

• withdrawal from pain

after reflexes, development of sophisticated motor behaviours follow two rules (Cephalocaudal Rule and Proximodistal Rule)

Cephalocaudal Rule

“top-to-bottom” rule that describes the tendency for motor skills to emerge in sequence form head to feet

Proximodistal Rule

“Inside-to-outside” rule that describes the tendency for motor skills to emerge in sequence from center to periphery

holistic nature of development

development in one domain influences development in another domain

cognitive development

emergence of ability to think about and understand the world

Jean Piaget

Swiss psychologist who pioneered the understanding of children’s cognitive development

Piaget’s Theory of Cognitive Development

1. sensorimotor stage (0-2 years)

2. Preoperational stage (2-6 years)

3. concrete operational stage (6-11 years)

4. formal operational stage (11 years - adulthood)

believed children are constructivists and move from one stage to the next as they gain knowledge about world

cognitive disequilibrium

when children acquire new knowledge that doesn’t fit within their existing schema

cognitive equilibirum

when children modify their schema to fit new knowledge (accommodation)

Imprinting

Konrad Lorenz’s work with geese

• biological predisposition that young organisms have to form relationships with their caregivers

Biological needs

Harry Harlow’s work with rhesus macaques (monkeys with two mothers)

• all infants require an attachment figure for normal development but there are major individual differences in how

Strange Situation Procedure

Mary Ainsworth developed to operationalize and measure the following variables:

• the extent to which an infant uses their caregiver as a secure base

• how the infants react to reunions with their caregiver after short separations

criticism of Piaget’s theory

• looked at human development from a species perspective - doesn’t account for individual differences

• claimed order of stages was invariant across individuals and cultures

• critics argue development looks more gradual and continuous rather than stage-like

Lev Vygotsky’s beliefs

• stressed the role of culture and cultural differences in development of child

• individuals gain knowledge by interacting socially and collaboratively with others

• encourages practice of scaffolding - parent being responsive to child’s needs and providing guidance that matches learner’s needs

strange situation: insecure-resistant attachment

Always uneasy, highly distressed when mother leaves - alternates between clingy and rejecting upon return

strange situation: secure attachment

Child is distressed when the mother leaves but easily comforted when she returns

strange situation: insecure-avoidant attachment

No distress when mother leaves, accepts comfort from stranger, avoids mother upon return

strange situation: disorganized attachment

wants to be close but also away from parent

Confused, contradictory behaviors (ex. approaching mother while walking backward)

infant attachment style prediction for adulthood

• academic achievement

• emotional health

• relationship quality

• self-esteem

self-esteem

what do individuals think about themselves

self-esteem across lifespan

• young children describe themselves in physical terms (positivity bias) - high self-esteem

• positivity bias declines as social comparison begins (cognitive skills increase and schools begin objective evaluations)

• adolescents have lower self-esteem (esp women)

• adults gain self-esteem gradually through development

• marked decline in older age

• however, compared to others, an individual’s self-esteem is relatively consistent (maintains rank-order stability)

rank-order stability

consistency of an individual’s relative ordering compared to others in a given sample

physiological changes that occur during adolescence

• puberty

• increase and refinement of connections in prefrontal cortex

psychological changes that occur during adolescence

• self-esteem

• identity

• sexuality

• morality

Erik Erikson’s Psychosocial Theory of Development

developed a theory of conflicts and resolutions that occur throughout lifespan

identity formation: identity diffusion

unable to make any decision about identity (role confusion)

identity formation: identity foreclosure

prematurely deciding on identity

identity formation: psychosocial moratorium

identity crisis; unable to make a choice regarding identity

identity formation: identity acheivement

high exploration and commitment to identity; stable sense of identity

adolescent egocentrism

• personal fable (think of themselves as unique and non-vulnerable

• imaginary audience (everybody must be thinking of me)

challenges & achievement in adolescence

• emergence of abstract thinking

  • personality traits become more important

• emergence of self-socialization

  • friends and social groups become of paramount importance

social clock

cultural expectations/norms for when milestones can occur

major milestones in adulthood include

1. marriage

2. parenthood

3. retirement

marriage predictions based on attachments

• secure or autonomous attachment: enjoys emotional closeness and independence

• anxious or preoccupied attachment: wants constant intimacy and avoids independence

• dismissive or avoidant attachment: prefers independence and avoids relationships

parenthood

may affect marriage but also related to positive emotion and meaning in life

retirement

successful adjustment impacted by financial resources and keeping an active lifestyle

dementia

deterioration of brain function

Alzheimer’s diseases

a form of dementia which includes impairments in memory, language and cognitive function

physiological changes in adulthood

• changes in sensory systems (e.g. vision, auditory)

• changes to brain structure (not always loss)

psychological changes in adulthood

• changes in memory storage and retrieval (memory tends to decline)

• slowing of cognitive processes

episodic memory

ability to remember past events

semantic memory

ability to remember general information (facts)

changes in selective attention in adulthood

• tend to remember positive stimuli better than negative

• amygdalae (emotional processing centers) are more activated by positive emotions than negative ones

socioemotional selectivity theory (adulthood)

• enhanced emotional well-being

• focus on building close relationships

• focus on emotion-related goals

• increased capacity for emotion regulation and well-being

• avoid negatively arousing stimuli and focus on maintain satisfying relationships

changes in relationships in adulthood

• older adults tend to value having close social groups

  • decline in number of social partners

  • increase in quality of social relationships

Erikson’s Psychosocial Theory: 0-1.5 years

conflict: trust vs mistrust

resolution: reliance on others

• if needs are dependably met, infants develop a sense of basic trust

Erikson’s Psychosocial Theory: 1.5-3 years

conflict: autonomy vs shame and doubt

resolution: independence

• toddlers learn to exercise will and do things for themselves, or they doubt their abilities

Erikson’s Psychosocial Theory: 3-6 years

conflict: initiative vs guilt

resolution: self-expression

• preschoolers learn to initiate tasks and carry out plans, or they feel guilty about efforts to be independent

Erikson’s Psychosocial Theory: 6-12 years

conflict: industry vs inferiority

resolution: work ethic

• children learn the pleasure of applying themselves to tasks, or they feel inferior

Erikson’s Psychosocial Theory: 12-21 years

conflict: identity vs identity diffusion

resolution: sense of self

• teens work at refining a sense of self by testing roles and then integrating them to form a single identity, or they become confused about who they are

Erikson’s Psychosocial Theory: 21-30 years

conflict: intimacy vs isolation

resolution: close relationships

• young adults struggle to form close relationships and to gain the capacity for intimate love, or they feel socially isolated

Erikson’s Psychosocial Theory: 30-65 years

conflict: generativity vs stagnation

resolution: care for younger generation

• middle-aged discover a sense of contributing to the world, usually through family and work, or they may feel lack of purpose

Erikson’s Psychosocial Theory: 65+ years

conflict: ego integrity vs despair

resolution: mortality and acceptance

• when reflecting on their life, the older adult may feel a sense of satisfaction or failure

primary circular reactions (1-4 months)

actions that involve the infant’s own body