life span development

types of development

physical, cognitive, social/emotional

continuity

development proceeds gradually and smoothly over time

discontinuity

development changes more abruptly from one stage to the next

universal development

age-related behaviors found across entire human species

ecological development

ask questions about the impact of culture and environemtn on development

zygote

• developing organism in first 2 gestational weeks

• in 1st week, zygote differentiates into ectoderm, mesoderm, and endoderm

• in 2nd week, zygote completes journey through fallopian tube to uterus, then implants in lining

gestation

process of development inside the uterus

embryo

gestational weeks 3 - 8

fetus

• term for organism in gestational period after 8 weeks

• ability to hear develops by 28 gestational weeks

3 layers on zygote

ectoderm, mesoderm, endoderm

ectoderm

develops into nerve tissue and skin

mesoderm

develops into muscle and bone

endoderm

develops insource of body’s soft tissue (i.g, organs of digestive tract)

gestation week 1

zygote differentiates into ectoderm, mesoderm, and endoderm

gestation week 4

CNS differentiates into forebrain, midbrain, hindbrain, and spinal cord

gestation week 7

cells that will form cerebral cortex begin journey from the lining of the neural tube (later ventricles of brain) to ultimate destinations

what develops during the embryonic stage?

heart, stomach, liver, and other organs

gestation week 6

expression of a gene on Y chromosome initiates differentiation of generic gonads into tester in males; other genes develop gonads in ovaries in females

gonads

produce gametes in reproductive organs

gestation month 3

• internal reproductive organs differentiate into uterus, fallopian tubes, upper portion of vagia in females; seminal vesicles, vas deferens, prostate in males

• new neurons born in large numbers, begin forming connections

what develops in females in gestation month 3?

uterus, fallopian tubes, upper portion of vagina

what develops in males in gestation month 3?

seminal vesicles, vas deferens, prostate

gestation month 6

• myelination of nervous system

  • allows neurons to communicate faster, more efficiently

gestation month 7

• most of neuron you will ever have are in place

• brain waves can be recorded through mother’s abdomen

when are babies born?

• between weeks 37 - 42

• in the US, about 10% of infants are born prior to 37 weeks

down syndrome

• trisomy 21

• child receives 3rd full/partial copy of 21st chromosome

• intellectual disability

• 1 in 2,000 chance of being born at mother’s age 20

  • chances rise to 1 in 30 when mother is 45

what does placenta do during pregnancy?

protects developing fetus from toxins and disease-causing agents (not perfectly efficient)

placenta

organ attached to wall of mother’s uterus that provides fetus with nutrients and oxygen

teratogen

any agent that can produce harmful effects in the zygote, embryo, or fetus

common teratogens

alcohol, tobacco (nicotine), cannabis, phenytoin (dilantin), selective serotonin reuptake inhibitors, varicella (chickenpox), zika, aspirin, acetaminophen

effects of alcohol

• small structure

• facial abnormalities

• hyperactivity

• intellectual disability

effects of tobacco

• low birth weight

• premature birth

• cleft lip

• risk of SIDS

• lung/brain damage

• possible link to ADHD

effects of cannabis

• autism

• intellectual/learning disability

effects of phenytoin (medication for epilepsy)

• heart defects

• intellectual disability

• cleft palate

• slow growth

effects of selective serotonin reuptake inhibitors (antidepressants)

• premature birth

• heart/other physical defects

• possibly autism

effects of varicella (viral infection)

• scars

• small head

• blindness

• seizures

• malformed and paralyzed limbs

effects of zika (viral infection)

microencephaly (significantly small infant head)

effects of aspirin (OTC pain meds)

• heart defects

• intellectual disability

• slow growth

effects of acetaminophen (OTC pain meds)

• ADHD

• autism

fetal alcohol syndrome (FAS)

condition resulting from alcohol consumption during pregnancy

• produces physical abnormalities and cognitive and behavioral problems in child

prenatal exposure to opioids

produces long-lasting cognitive and motor deficits

gray matter and teratogens

• mother’s use of alcohol, tobacco, marijuana, or cocaine —> reduces gray matter in child’s brain

• gray matter is populated areas of neural cell bodies, thicknes correlated with intelligence

when do kids exposed to multiple drugs prenatally show reduced gray matter thickness and head circumference?

10 - 13 years of age

when do physical abilities appear in human infants?

about 1 year

how long does newborn stage of life last?

birth to 28 days

newborn reflexes

babinski, blink, moro, palmar, rooting, stepping, sucking

babinski

stroking baby’s foot causes toes to spread

blink

eyes close in response to strong stimuli

moro

if head falls back, arms first spread out, then “hug”

palmar

placing object in hand —> reflexive grasping

rooting

stroking baby’s cheek results in baby turning toward touch and opening mouth

stepping

placing baby’s feet in flat surfance initiates stepping

sucking

baby sucks anything that touches roof of mouth

how long do newborns sleep?

16 - 18 hours (large portion in REM sleep)

how long do newborns spend a day crying?

2 - 3 hours

sex

physiological characteristics (XX/XY genotype)

gender

psychosocial aspects of maleness-femaleness continuum

intersex

presence of male and female features in one individual

androgen insensitivity syndrome (AIS)

genetic males (XY) who do not respond to circulating male hormones in utero (period inside uterus before birth)

• female external appearance

turner sydrome

individuals have a single X chromosome, phenotypically female

klinefelter syndrome

two X chromosomes and one Y chromosomes, phenotypically male

Jacob syndrome

one x chromosome and two Y chromosomes, phenotypically male

• high rates of autism

5-alpha-reductase syndrome

results in ambiguous genitalia at birth with later masculinization at puberty

congenital adrenal hyperplasia (CAH)

• exposes fetus to excess male hormones

• little effect on male sexual development

• might masculinize external genitalia and behavior of genetic females

habituation

we reduce responding to repeated stimuli

• this is why babies gaze longer at new stimuli than ones they have seen before

newborn senses

• sensitive to smell (especially mother’s)

• quite sensitive to taste (sweet, sour, bitter, salty)

• infant prefer sounds with higher frequencies (why parents use “motherese”

• prefer more contrast in visual stimuli (large, high-contrast, colorful objects preferred)

brain in first 18 months of life

human brain shows rapid grwoth in gray matter (collections of neural cell bodies)

brain between birth and end of infant’s 3rd month

brain grows 64%, goes less than ¼ to abour ½ of adult brain size

brain by age of three

about 80% of eventual adult size brain

“use it or lose it” principle

• nervous system wires brain

• children in stimulating environment with many things to explore —> best outcomes

• children in intellectually impoverished circumstances —> retain few connections, mild forms of intellectual disability

when do children begin to prefer sex-typed toys?

between ages of 12 and 18 months, but cannot differentiate between toys with male and female voices specifically

ovotesticular syndrome

• true hermaphrodite (both male and female genitalia)

• possess gonad that contains both testicular tubular structures and ovarian follicles

• half of the newborns in this category are assigned to male, other half female

  • causes them in later life to experience gender dysphoria

jean piaget’s theory of cognitive development

• discontinuity (stages)

• cognitive abilities develop through regular stages

• cognition matures as child increasingly uses concepts and schemas to think

• sensorimotor stage, preoperational stage, concrete operational stage, formal operational stage

two types of adjustments to schema

assimilation, accommodation

assimilation

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

accommodation

schema must be adapted to fit new information, requires revision of the schema

sensorimotor stage

• birth to age 2

• emphasizes present over past and future

• exploration through moving/sensing

• object permanence

preoperational stage

• 2-6 years

• language acquisition

• egocentrism

• illogical reasoning

• theory of mind begins to develop (more than one perspective)

concrete operational stage

• 6-12 years

• logical reasoning

• mastery of conservation problems

• learning by doing

• theory of mind (more than one perspective)

• unable to distinguish fantasy from reality

formal operational stage

• 12 years +

• abstract reasoning

• idealism (reality is mental/spiritual, not physical; ideas, mind, consciousness are primary reality)

• improved problem solving

conservation

changing form/appearance of an object does not change its quantity

egocentrism

limited abilities to understand points of view other than their own

flaw with piaget’s theory

one major part of his theories was based entirely on observing his own three children

piaget vs vygotsky means of gaining knowledge of the world

• piaget - understand world by actively exploring it

• vygotsky - interact socially with parents, teachers, other members of community; emphasis on language to communicate; inner speech (self-talk)

zone of proximal development

till what age does attention span remain limited?

• 11 years of age

• attention span significantly lengthens each year until adulthood after

when do humans first begin producing autobiographical memories?

• between ages 3-5

• improved memory + growing sense of self = autobiographical mems

theory of mind (TOM)

• people understand that others have beliefs, desires, intentions different from their own

• emerges around 3-4 years (earlier than piaget's theory)

• joint attention

• distinction between living/non-living

• distinction between intentional/unintentional behaviors

• failure to develop linked to autism

“sally-anne” task

• a doll, sally, places her ball in basket, then leaves room

• another doll, anne, enters room and moves ball from basket to box, then leaves

  • if sally comes back, where will she look?

• kids who developed TOM understand that just because they saw the ball was moved, sally will not know the ball was moved, so she will look in the basket

joint attention

shared focus of two individuals on one object

• emerges in first year of life

temperament

• prevailing patterns of mood, activity, and emotional responsiveness

• differences predict adult personality

• surgency or extroversion, negative affect or mood, effortful control

three categories of temperament

• surgency or extroversion

• negative affect or mood

• effortful control

surgency or extroversion

happy, active, vocal, social

negative affect or mood

angry, fearful, shy, frustrated

effortful control

ability to pay attention and inhibit behavior

MAOA and aggression

• variations in MAOA → aggressive behavior in rhesus monkeys

• low activity → more aggressive, more dominant when raised by mothers

• high activity → more aggressive when raised by peers

harlow’s rhesus monkey experiment

• studied infant attachment

• removed baby rhesus monkeys from mothers at birth and provided wire mother and carpet mother

• regardless of which one provided food, infant monkeys spent more time with cloth mother

• conclusion → contact comfort is more important to attachment than food

attachment

• emotional bond linking infant to parent/caregiver

• mobility predicts timing of attachment

  • human infants are mobile around first half/second year of life, more time to bond

what does touch enhance?

• immune, endocrine, nervous system development

• reduces stress, promotes infant social behavior toward caregivers

secure attachment

children explore confidently and return to parent/caregiver for reassurance

• when parent left room, child responded by searching, crying

• efforts to calm down by stranger were rejected

• caregiver greeted warmly when returned