dev psych

Continuous

children gradually add more of the same types of skills that were there to begin with

Discontinuous

Children change rapidly as they step up to a new level and then change very little for a while

sociocultural context

Children grow up in distinct contexts with unique combinations of personal and environmental circumstances which reflect different paths of change

nature

hereditary information we receive from our parents

nurture

complex forces of physical and social world that influence biological makeup and psychological experiences before and after birth

sensitive/critical periods

origin of knowledge & behavior; blank slate or innate knowledge

genetic & environmental variation

What makes us different?

naturalistic context

minimal interference

structured context

uniform context (ex: lab)

advantages of naturalistic context

natural/high external validity, good for social interaction

disadvantages of naturalistic context

lack of control/low internal validity, miss rare behaviors

advantages of structured context

control/high internal validity, force rare behaviors

disadvantages of structured context

low external validity

internal validity

the extent of which we can say that the changes in the dependent variable were caused by the independent variable

external validity

the extent to which findings can be generalized to other people

advantages of structured interviews/surveys

query things that are impossible to observe, efficient

disadvantages of structured interviews/surveys

inaccurate reporting (bias, dishonesty/social desirability)

correlation design

Measuring the relationship (correlation coefficient r) and strength of relationships between two variables

correlation coefficient r=0

no relationship

correlation coefficient r>0

positive relationship (if one variable increases so does the other)

correlation coefficient r<0

negative relationship (one variable increases but the other decreases)

components of experimental design

manipulation of groups, random assignment

No! there may be a confounding/third variable

does correlation=causation?

assume causality

what does random assignment allow you to do?

cross-sectional study

• different children for each age group

• typical trajectory or average change

  • ex: vocabulary or friendship quality in different grades

logitudinal

• think prediction

• same children over time

• stability of individual differences

• ex: do individual differences in vocabulary size in kindergarten predict

  • Individual differences in vocabulary in 3rd grade?

  • Individual differences in reading achievement in 3rd grade?

microgenetic

• think microscope

• Examining change as it happens during a developmental transition and characterizing that change

• What change looks like, not prediction

• Period of rapid change/transition

• High frequency of observations

• Understanding the transition is more important than prediction

gamete

specialized reproductive cells (sperm and eggs) that carry half the genetic information needed to form a new organism

autosomes

most traits

sex chromosomes

sex determination + some traits

gene

a stretch of DNA that codes for a protein or functional RNA, acting as the basic unit of heredity

alleles

different versions of the same gene that can produce variations in traits

homo

same (alleles match)

hetero

different (alleles differ)

genetic influences

• Different alleles contribute to variation in traits

• Some traits are highly heritable

• Twin and adoption studies help measure heritable traits

environmental influences

• Shared environment- factors siblings share (socioeconomic status, parenting style)

• Non-shared environment- unique experiences (life events, friends)

• Cultural context- also shapes traits like values, personality, ad behavior

behavior genetics

the study of how genetic and environmental factors work together to produce individual differences in behavior and psychological traits

logic of classic twin study

• Identical/Monozygotic (MZ) twins 100% shared alleles

• Fraternal/Dizygotic (DZ) twins 50% shared alleles

• Take correlations for MZ and for DZ twins

• If identical twins are more highly correlated than fraternal twins for some trait, it can only be due to more shared gene

Concept of heritability and environmental differences as a sources of individual differences/variance

Proportion of variance that is due to genetic variance/ Extent to which genes explain individual differences

where do the remainder of individual differences come from?

environmental factors (shared by family, unique to individual, social, biological)

52% of differences can be attributed to genes (and 48% to environment)

What does it mean if heritability is .52?

Gene-environment correlations

passive, evocative, and active

Gene-environment interactions

The effect of one variable depends on the level of the other variable

Gene-environment correlations: passive

Parents provide environments influenced by their own heredity (Example: Athletic parents & athletic home environment)

Gene-environment correlations: evocative

Children evoke responses that are influenced by their own heredity (Example: Friendly baby, more attention)

Gene-environment correlations: active

Children seek environments that fit their genetic tendencies

gestation

38 weeks from conception to birth

pregnancy

dated from last menstrual cycle which is 2 weeks prior so pregnancy is 40 weeks

2 weeks before conception

when does pregnancy start in the medical world?

zygote/germinal stage

0-2 weeks

embryo stage

3-8 weeks

fetus

9-28 weeks

end of second week pregnancy

placenta—filters blood, fills amniotic sac

embryo

what stage of development is most rapid with the most vulnerability

cell differentiation

what happens during the embryo stage?

4 weeks

when does heartbeat develop?

5 weeks (250,000 neurons produced per minute)

when does neural tube develop?

5-6 weeks

when does movement begin during pregnancy?

8 weeks

when would production of testosterone in males occur for the masculinization of body?

9 weeks

when are all internal organs present?

growing & finishing

what happens during the last 3 months of pregnancy?

10-12 weeks

when is there heart & brain structure?

10-12 weeks

when does there appear to be breathing, gasping, swallowing, sucking?

28-29 weeks

when can fetus start hearing external sounds?

30-34 weeks

when does fetus develop sleep/wake cycle?

by 9 weeks

when does fetus become responsive to touch?

23-30 weeks

when does fetus become responsive to pain?

28 weeks

when does fetus develop sight?

taste & smell

what sense persist as preferences postnatally?

Mennella et al (anise & carrot juice)

what study showed that taste & smell preferences are passed through the placenta and persist postnatally?

29 weeks (habituation to repeated sound stimuli)

when does hearing develop in fetus?

Heartbeat increases for mother’s voice, mother’s language, heartbeat habituation/dishabituation

indicators that fetuses can discriminate and prefer their sounds

non-nutritive sucking

newborns respond to a poke on the cheek with sucking reflex

language discrimination

infants habituate/dishabituate sucking response with native vs non-native language

DeCasper & Spencer 1986 study

moms randomly assigned to read The Cat in the Hat or to control group. Found that newborns recognized & preferred a story they had heard prenatally, therefore fetuses remember auditory experiences from the womb

newborn states of arousal

sleep/wake, drowsiness, quiet alertness, waking activity/crying

reflex

innate, fixed pattern of action that occurs in response to specific stimulation

newborn reflexes

rooting, palmar grasp, tonic neck, moro/startles, stepping

3 weeks

when does rooting reflex disappear?

3-4 months

when does palmar grasp reflex disappear?

4 months

when does tonic neck reflex disappear?

6 months

when does more/startle reflex disappear?

6 months

when does stepping reflex disappear?

healthy development

what are reflexes a sign of?

teratogens

agents that cause harm during prenatal development (able to cross placenta)

filter  

what is the role of the placenta?

factors that affect severity of teratogen

dosage (the more teratogen the fetus is exposed to the worse the affect) and timing

sensitive period

time of greatest vulnerability for fetus; during embryonic stage when body parts/systems are forming

specific teratogens

thalidomide, isotretinoin, nicotine, alcohol, lead, rubella

thalidomide

Prescribed to pregnant women in early 60s for morning sickness- babies born had missing arms and legs (structural defects)

isotretinoin

Acne Medication- exposure during the first trimester results in eye, ear, brain, skull, heart, and immune system abnormalities

nicotine

• Constricts blood flow and lessens blood flow to uterus causing placenta to grow abnormally

• Reduces nutrients to fetus gains weight poorly 

• Raises carbon monoxide in blood stream- damages central nervous system and slows fetal body growth

alcohol

Dose and timing related impacts, fetal alcohol syndrome

fetal alcohol syndrome (FAS)

• At least two of the three characteristic facial abnormalities

  • Short eyelid opening

  • Thin upper lip

  • Smoothed or flattened philtrum

• Deficient physical growth (height or weight below 10th percentile)

• Deficient brain growth or brain injury ( small head or confirmed through brain imaging

• Substantial cognitive and behavioral impairment in self-regulation

lead

• High levels of prenatal exposure associated with prematurity, low birth weight, brain damage and other varieties of birth defects

• At low levels children show poorer mental and motor development

rubella

• Greatest damage when striking in embryonic period

• 50% of infants whose mothers become ill during that time are born with some or all of the following: deafness, eye deformities, heart, genotal, urinary, intestinal bone, and dentinal defects

• can also lead to life health problems such as severe mental illness, diabetes, cardiovascular disease, and thyroid and immune-system dysfunction

preterm

baby is born more than 2 weeks early

2,500 grams (5.5 lbs) or less

low birth weight

greatest risk in preterm birth

small for gestational age

immediate consequences of preterm birth

medical, risk for abuse (crying, passivity, unresponsive)