Developmental psych 241

child development

the scientific study of change and stability in the child's biological, cognitive, social and emotional functioning across the span of childhood.

Nature vs nurture

ancient Greece

• Plato - innate knowledge

• Aristotle 

17th & 18th century

• John Locke - tabula rasa, blank slate = gain knowledge through experiences

• Jean Jacques Rousseau - noble savage, humans are inherently good, but corrupted by society 

1920s & 30s

• Arnold Gesell - development is a biological timetable

• John Watson - tabula rasa 

Passive vs Active child

A = influences their own development, actively seeks engagement, and shapes their environment
P = shaped by their environment, less likely to initiate interaction, may internalize feelings

How to characterize the nature of change across development?

Continuity = quantitative change

• slope

Discontinuity = qualitative change

• steps scale

Mechanisms of development !!

What are the determinants of change?

How does sociocultural context influence development?

• physical 

• social 

• cultural 

• economic 

• historical 

Why do children differ?

universal patterns of development = predictable stages, milestones, and principles

individual differences 

How can we use findings from developmental research to promote child health and well-being?

• interventions

• social policy 

Correlational strategy

|1| closest
- positive ↑↑ or ↓↓
- negative ↑↓

Spurious correlation

have a strong correlation, but 2 random factors that happen to have a correlation

What is the “golden rule” about correlations? 

correlation does not equal causation 

experiments

1. lab

2. field 

3. natural 

   1. observe in a natural state

   2. no random assignment

Cross-sectional design

simultaneously compare diff age groups

longitudinal design

observe same ppl at diff points in their development

microgenetic design

Small number of subjects are repeatedly observed over a short period of time in order to study change in a developmental process

cohort effect

the variation in behaviors, characteristics, or outcomes among groups of people who share a common life experience or temporal event

Binocular Depth Perception

assumed pattern: positive slope, 13-24 weeks
actual pattern: stagnant then slope, then stagnant 

genotype 

genetic makeup of an individual 

phenotype 

expression of genotype in observable or measurable characteristics

• genes + enviro 
  

Genes 

basic units of inheritance 

chromosomes 

in cell nucleus 

• somatic/body cells 

• gametes/sex cells 

somatic cells duplication 

process of cell replication

1. prophase = duplicated chromosomes 

2. metaphase = individual chromosomes line up at the metaphase plate 

3. anaphase = sister chromatids separate

4. daughter cells of mitosis 

gametes cells duplication 

Meiosis 1 

1. prophase 1 = cross over

2. metaphase 1 = pairs of homologous chromosomes line up at the metaphase plate

3. anaphase 1 + telophase 1 = homologs separate during anaphase 1; sister chromatids remain attached at centromere 

4. Meiosis 2 = sister chromatids separate during anaphase 2

2^n possible combos 

3 ways that heterozygous combos can be expressed

1. intermediate = average between 2 genes

2. combined = shows both characteristics

3. dominiance = the dominant one shows

4th rare possibility

genomic imprinting = one parental copy of a gene is silenced, while the other is expressed

• prader-willi syndrome = deletion of chromosome

• Angelman syndrome = deletion of chromosome on maternal copy

Achondroplasia 

single gene dominant disorder 

• firoblast growth factor receptor 3 (FGFR 3) gene 

  • 80% of ppl have unaffected parents 

Transmission sex-linked characteristics 

determined by genes on sex chromosomes (X or Y) 

• X-linked recessive trait = hemophilia, color blindness

  • men are more prone since mom could be a carrier and sex of kid is determined by dad, only need 1 copy of the defective gene on their single x chromosome 

Down syndrome 

aka trisomy 21 

• added chromosome on the 21st 

klinefelter’s syndrome 

have 47 karyotype instead of 46 

• extra X = XXY

Turner syndrome 

have 45 karyotype 

• only X 

Behavioral genetics

genetic + environmental contributions to individual differences

• why do ppl differ?

  • multifactorial, polygenic

Heritability

focused on variance
- the proportion of variability in the behavior that can be attributed to genetic factors

h62 = genetic variance / genetic variance + environmental variance 

variability can be due to 

• genes 

• environments 

genotype-environment interactions

genetically based variations of individual’s responsiveness to environments
- range of reaction or norm of reaction

Behavior genetic methods

• family studies 

• twin studies 

• adoption studies 

• combination twin/adoption studies 

piaget

• led the way to most modern theories of development

• influence of biological ideas

• worked w/ Binet

  • first intelligence test

  • older children made diff types of mistakes and approached the question diff

  • child’s brain was adapting to environment

general concept of piaget

knowledge is a process

• cognitive structures = ways of interacting w/ to understand the world

  • schemes = organized patterns of behavior, physical activities

  • operations = mental activity

• cognitive processes

• predisposition to integrate

  • organization = higher order, organize cognitive structure into complex systems 

  • Adaptation = the ability to adapt to environment (general measure of intelligence) 

    • assimilation = fitting new info into our existing schemes 

    • accommodation = changing our schemes to fit a new piece of info

    • equilibrium = a natural process of balancing new information with existing knowledge through the complementary processes of assimilation (fitting new info into old schemas) and accommodation (changing schemas to fit new info).

characteristics of piaget’s stages 

• each stage is qualitatively different

• stages build upon each other

• stages follow an invariant sequence

• stages are universal

sensorimotor period (birth to 2 years)

Stage 1: Reflexes (birth to 1 month)
Stage 2: Primary Circular Reactions (1 to 4 months)
Stage 3: Secondary Circular Reactions (4 to 8 months)
Stage 4: Coordination of secondary circular reactions (8 to 12 months)
Stage 5: Tertiary Circular Reactions (12 to 18 months)

• invisible displacements 

• A not B error

Stage 6: New means through mental combinations (18 months to 2 years)

• chain inside match box 

  • prior he had the matchbox open w/ chain inside 

  • gears churning = mouth opening 

• tied to infant’s actions

primary circular reactions

simple repetitive act that centers around child’s own body

• ex: thumb sucking

secondary circular reactions

accidentally, infant acts to repeat it

• squeeze that, quack quack
  object permanence is developed, goal-directed behavior

tertiary circular reactions

how variations effect outcome

• drumming w/ different objects

babies start to showcase “trial and error” = become like scientists

object permeance 

“out of sight, out of mind” more like out of existence

• they don’t exist independent of the self

Piaget’s A-not-B error

incorrectly search for a hidden object at a previously correct location (A) even after watching it be hidden at new location (B)

pre-operational period (2-7 yrs)

1. Egocentrism = unable to see other people’s perspectives 
2. Animism = giving life like personality to an inanimate object, using pronouns on the object 
3. Intuitive reasoning = ability to understand a concept immediately w/o systemic analysis, reliance on instinct, imagination, and prior knowledge rather than logocal reasoning 
4. Rigidity of thought = inability to adapt to new info, failure to see alternative way of thinking 

• centration

• states vs transformations 

• lack of reversibility

3 mountain problem

• take child around and ask what they see

• tell me what the doll sees 

  • but the kid talks only about what they see, not what the doll might see 

showcases egosentrism