developmental psychology exam 1

nature and nurture: how do nature and nurture together shape development?

nature and nurture: how do nature and nurture together shape development?

• Genome: complete set of hereditary infromation

• Epigenetics: study of stable changes in gene that are mediated by the enviornent

• Methylation: a biochemical process that influences behavior by suppressing gene activity and expression (enviornment effects how express our inheritance)

• Nature: influenced by heredity

• Nurture: influenced by environment (everything else)

the active child: how do children shape their own development?

• Idea that child themselves is active in their own development

• Variation after first words naming parents

• Children choosing what theyre interested in and attentive to

in what ways is development continuous, in what ways is it discontinuous?

• Continuity: process of small changes

  • Most things in developmental science → cognition

• Discontinuity: a series of sudden changes

  • Quantitative changes, observably distinct

  • Puberty

• Depends how you look at it

how does change occur (mechanisms of change)?

• Why or how changes occur

• Combination of Brain structures/networks, genetic predisposition, environmental factors

• Effortful attention: voluntary control of emotions and thoughts

how does the sociocultural context influence development?

• Influences every aspect of development

• Social

• Culture

• Physical

• Socioeconomic status

• Historical circumstances

• SES (socioeconomic status) - those in poverty might face malnutrition, higher stress

• different cultures - may be subjective to cultural norms such as women being raised to be mothers/wives

how do children become so different from one another? (individual differences)

• 4 factors

  • Genetic differences

  • How they are treated by parents and others

  • How they react to similar experiences

    • Our own temperaments

    • Even if we experience the same things, we can react differently (inidvidual reactions)

  • Envionrmental differences 

4 factors of individual differences

• 4 factors

  • Genetic differences

  • How they are treated by parents and others

  • How they react to similar experiences

    • Our own temperaments

    • Even if we experience the same things, we can react differently (inidvidual reactions)

  • Envionrmental differences

correlation does not equal causation

correlation: the association between 2 variables

• the concept that a correlation between two variables does not indicate which, if either, variable is the cause of another

cross-sectional design

• when cohorts of different groups of children are studied over the same time period (cheaper)

longitudinal design

• when the same cohort of children are studied over a long duration (months, years) → expensive but benefits entire scientific community

micro genetic design

Sequential

Several similar cross-sectional or longitudinal studies are conducted at varying times

continuous development theories

• although many stage theories were once high influential, in the past few decades, many researchers have concluded that most developmental changes are gradual rather than sudden and development occurs concept by concept rather than in a broadly unified way

• children could behave in accord with one stage in some tasks but another stage in other tasks

discontinuous development theories

• researchers who view development as discontinuous start from a common observation: children of different ages seem qualitatively different

  • i.e. the difference in response on the conservation of liquid problem between a 4 and 6 year old

• stage theories: development occurs in a progression of distinct age related stages

  • according to these theories a Childs entry into a new stage involves relatively sudden, quantitative changes that affect the child’s thinking/behavior in broad ways

jean Piaget’s theory of cognitive development

• best known stage theory

• holds that between birth and adolescence, children go through four stages of cognitive growth, each characterized by distinct intellectual abilities and ways of understanding the world

habitation

stages of prenatal development

conception, gametes, zygote, embryo, fetus

conception

• Egg launched from ovary into fallopian tube

• Triggered by sexual intercourse, egg released and sperm enter vagina

• High failure rate due to genetics or other defects; survival of fittest

gametes

• Gametes are produced through meiosis and contain 23 chromosomes; when united, 23 pairs result.

• All humans originate from union of two gametes (sperm from father; egg from mother).

• Almost all eggs are formed prenatally; sperm production continues throughout life.

• zygote

germinal period of prenatal development

begins with conception and last until zygote becomes implanted in uterine wall. rapid cell division takes place

zygote

• the fertilized egg (when the sperm connects with the egg during conception) with a full complement of genetic material - 23 chromosomes from each parent

• zygote is when the organism is single celled → becomes embryo when cell division starts

embryo

• week 3-8

• when zygote starts dividing and becomes multicellular, that is an embryo

• 4 major developmental processes transform the zygote into an embryo and then fetus

  • the first is cell division (mitosis)

  • the second is cell migration where newly formed cells move away from their origin point

  • the third is cell differentiation - the embryonic stem cells start to specialize after the cell divisions are complete → when the cells start to specialize, zygote becomes embryo

  • the fourth is apoptosis - programmed cell death

• the inner cell mass becomes embryo and rest of cells become elaborate support system

  • during 3rd week, inner cell mass folds into 3 layers

• neural tube is created: brain and spinal cord

fetus

• 9th week to birth

• continued development of physical structures and rapid growth of body

• increasing levels of behavior, sensory experience, and learning

amniotic sac

transparent, fluid-filled membrane that surrounds and protects the fetus

placenta

support organ for the fetus; keeps circulatory systems of the fetus and mother separate, but as a semipermeable membrane permits the exchange of some materials between them

umbilical cord

tube containing the blood vessels connecting the fetus and placenta

dose-response relation

• significant with exposure to teratogens and lead

• Increases in exposure to potential teratogens (cumulative effect) are associated with greater probabilities of fetal defects and with more severe problems.

• more exposure equates to more severe problems

cumulative risk

risk of developing a certain condition will increase with amount of hazards the baby has been exposed to (malnutrition, teratogens, etc.)

development of sex

• Males

  • Sperm carry Y chromosome, lighter and faster than those carrying X

    • Y chromosome is stunted, doesnt have as many genes, more successful

• Hormonal infleunce

  • Important to cell differentiation (androgens)

  • Next stage of sex differentiation

  • If fetus has Y chromosome, will ramp up production of testosterone which will cause male genitalia to emerge

  • Being female is absence of being male

genetic inheritance

• the fertilized egg (when the sperm connects with the egg during conception) with a full complement of genetic material - 23 chromosomes from each parent

monozygotic twins (identical)

• result from a splitting in half of the inner cell mass (around the 4th day after conception) so they have the same genetic make up

dizygotic twins (fraternal)

• result when two eggs happen to be released from the ovary into the Fallopian tube and both are fertilized

• no more genetically alike than non twin siblings with the same parents because they originate from different eggs and different sperm

maternal factors

• age

• nutrition

• disease

• emotional state

age

• age of parent related to pregnancy outcomes

• infants born to teens 15 or younger are 3-4 times more likely to die before their first birthday than infants born to 23-29 year olds

• dose-response relationship with risk of negative outcomes for mom and baby increasing with maternal age

nutrition

• pregnant parents who don’t get enough folic acid are at risk of having baby with a neural tube defect (like spina bifida)

• malnutrition is most common with low income families so usually coincides with other risk factors

• dutch hunger winter

disease

• if contracted early, rubella can cause deafness, blindness, and intellectual developmental disorders

• STIs are also hazardous to the fetus

• CMV (a type of herpes) can damage the fetus’ central nervous system and cause a variety of other serious defects

• genital herpes can also cause blindness or even death

• zika can cause microcephaly (small head)

• COVID19 increased risk of still birth (fetal death after 20 wks)

emotional state

• effects of stress during pregnancy have been observed on myriad aspects of infant and child development ranging from infant cognitive development to later psychiatric diagnoses

• caused by alteration of HPA axis and hormone cortisol

• racial and ethnic minority groups report higher rates of maternal stress

environmental factors

• a vast number of environmental agents, called teratogens, have the potential to harm the fetus

• effect of teratogens are based on timing - many only damage if theyre presented at a sensitive period

• air pollution from fossil fuels is associated with LBW and neurotoxicity and affects low income populations more globally

• in Michigan, there were high levels of lead in the water supply due to corroded pipes - its a potent neurotoxin and can lead to development of ADHD symptoms and effects on intelligence and academic achievement

• nano plastics were discovered for the first time in the human placenta in 2021

teratogens

• drug thalidomide - taken between 4th and 6th week for morning sickness caused arms to not fully develop (1960s); wasn’t harmful if it was taken after limbs developed

• most teratogens show dose-response relation (more you take, larger impact)

• teratogens frequently occur in combination (poverty - poor nutrition, pollution, inadequate prenatal care)

• babies may not show effects until later on like during the dutch hunger winter

hazards to prenatal development: drugs

• antidepressants: evidence regarding whether these medications are harmful to the fetus is inconclusive; treatment for depression during pregnancy can help reduce the risk for postpartum depression (which effects 10-30% of people who’ve given birth)

• opioids: they are designed to mimic neurotransmitters so have potential to wreak havoc on the developing brain

  • neonatal abstinence syndrome: drug withdrawal seen in babies exposed to opioids in the womb; common effects include LBW, seizures, problems breathing and feeding - treatment includes methadone

  • copresence of other drug use increases chance for NAS

• marijuana: effects on fetus are inconclusive because many users also use cigarettes and alcohol (difficult to tease effects of each drug apart)

  • however, associated with range of problems involving attention, impulsivity, learning and memory (in older kids)

• cigarettes (nicotine): fetus makes fewer breathing movements while the parent is smoking and fetuses can metabolize some of the cancer causing agents; secondhand smoke has an indirect effect as well

  • leads to slowed fetal growth and LBW

  • linked to increased risk of SIDS

  • dose-response relationship including higher likelihood of stillbirth

  • effects of smoking are greatest early on in gestation

• alcohol: leading cause of fetal brain injury

  • alcohol in blood of parent crosses the placenta into the bloodstream and amniotic fluid

  • fetus has less ability to metabolize and remove alcohol from its blood - remains in system longer

  • can result in FASD- characteristic set of facial features, varying degrees of intellectual developmental disorder, attention challenges, and hyperactivity

  • LBW, increased risk for ADHD, and delays in cognitive development/school achievement

habituation

fetuses grow bored if a stimulus is repeated over and over again - a decrease in response to repeated or continual stimulation

• fetuses grow bored if a stimulus is repeated over and over (habituation) - provides evidence of learning and memory

fetal learning

• fetuses as young as 30 wks show habituation to both visual and auditory stimuli

• auditory - fetal heart rate increased when listening to a recording of mom vs a stranger → indicate they recognized and remembered moms voice

• newborns prefer to listen to language they heard in womb vs other languages

• also learn tastes and smells in the womb

  • remember scent of amniotic fluid

  • long lasting taste preferences observed (moms drank carrot juice for last 3 wks of pregnancy - babies 5.5 months preferred cereal w carrot juice vs water)

• can learn general sounds not specific content because liquid environment of womb

birth experience

• hormone oxytocin causes rhythmic uterine contractions that initiate birthing process (pitocin is synthetic hormone given to induce)

• as fetal lungs mature, produce protein that helps initiate labor

• as muscles contract, fetus is pushed through uterus and towards vagina - needs to be in head down position or considered breech

• after baby is born, birth process concludes with delivery of placenta (retained placenta can lead to serious bleeding after brith)

newborn states

• sleep

  • sleeps twice as much as adults - 16 hrs

  • REM sleep (dream sleep-believed to help develop infants visual system) accounts for 50% of sleep

  • natural jerking movements (myoclonic twitching) that occur during REM may help infants develop sensorimotor map

  • sleeping brains dont disconnect from external stimulation (allow them to learn during sleep)

  • sleep patterns might be influenced by breastmilk hormones

• crying

  • Increases after birth and peaks around 6 weeks; decline to about 1 hour daily for first year

  • Peak time is late afternoon and evening

  • rare cases, parents may react to crying with child abuse called shaken baby syndrome - causes head trauma

  • Adult aversion to crying may have adaptive value.

  • Early in infancy, crying reflects discomfort or frustration.

  • Crying is gradually a more communicative act.

SIDS

• sudden infant death syndrome

• cigarette smoking can contribute to SIDS because of lack of oxygen getting to baby

• unexplained and unexpected death of an infant younger than 1 yr old

• leading cause of infant mortality unrelated to congenital issues or prematurity

• causes of SIDS likely involve interaction between underlying biological issue that places infant at risk and an environmental stressor (limited oxygen due to obstruction of mouth or nose)

• some infants who succumbed to SIDS had decreased levels of serotonin making it more difficult to respond to lack of oxygen

• subset of cases result from genetic mutation in breathing muscles that puts infant at greater risk of respiratory challenges

• put babies to sleep on their back, dont smoke near baby, bedding should be firm (soft bedding traps air around face)

reflexes

• eye blink - Protects infant from strong stimulation

• rooting -Infant’s head turns toward source of stimulation; helps infant find the nipple

• sucking -Permits feeding

• moro - An “embracing” motion; in evolutionary past, may have helped infant cling to mother

• palmar grasp - Infant grasps finger; prepares infant for voluntary grasping

• tonic neck - Infant lies in a “fencing position”; may prepare infant for voluntary reaching

• stepping - Prepares infant for voluntary walking

• babinski - Toes fan out and curl as foot twists in when sole of foot is stroked; function unknown

infant mortality

• death during the first year after birth, rare in industrialized world

• US infant mortality rate is far higher than other industrialized nations

• infant mortality rate is so high in US for many reasons most having to do with poverty

• increased access to prenatal care improves infant mortality rate in US

newborn care

• crying and soothing

  • rocking

  • singing

  • holding infant to shoulder

  • pacifier

  • swaddling: wrapping baby tightly in blanket restricting limb movement which provides constant high level of of tactile stimulation and warmth

  • soothing touch

  • placing small drop of sweet substance on tongue

microgenetic design

• task analysis

• short time frame

• analyzing behavior as it develops

• moment by moment observation

sequential design

• stacking longitudinal and cross sectional designs to avoid cohort effects

  • for example - cohort A is studied for a long duration, 20 years later cohort B is studied, 10 years later cohort C is studied (for the same duration****)

  • cohort effect: characteristics among group of individuals defined by some shared experience such as birth year

breastfeeding/nutrition

• exclusive diet of breastmilk for under 6 months

• different flavors depending on what mom eats

• contains hormones, good bacteria (for gut), antibodies

• breastfed babies have shown cognitive benefits (higher IQs)