Developmental Psychology Notes PDF

# L1. Intro to Developmental Psych. ## Patterns of development. * **Quantitative change:** gradual change in the amount/quantity of a given process (without altering its fundamental nature). * **Qualitative change:** more dramatic shift, where new functions emerge abruptly (fundamental changes i...

# L1. Intro to Developmental Psych. ## Patterns of development. * **Quantitative change:** gradual change in the amount/quantity of a given process (without altering its fundamental nature). * **Qualitative change:** more dramatic shift, where new functions emerge abruptly (fundamental changes in the process). * **U-shaped change:** temporary setlbacks before improvement (a subset of qualitative change; temporarily incorrect approach). * **Atypical development:** * **Delay:** develop along the usual pathway, but at a slower pace. * **Divergence:** development at a faster/slower rate not following the typical trajectory. ## Studies * **Case et. al (1982): Counting span task** * Quantitative change, children's working memory capacity increases with speed and efficiency as they age. * **Hitch et al. (1989):** Qualitative change in memory strategies, as older children (11 y.o) use phonological strategies over visual ones (while 5 y.o. mainly use visual strategies). * **Marcus et al. (1992):** U-shaped change * Children learn past tense verbs individually, but at some point they overgeneralize (add -ed at the end) reflecting temporary regression before adopting the final (correct) strategy. * **Roch & Jarrold (2008):** Phonological awareness test (odd one out) * Down syndrome individuals show delay in Down Syndrome between PA and nonword reading, but same relationship. * **Brock & Jarrold (2005):** Short term memory in Down Syndrome. * **Divergence:** Digit task performance is lower than expected given spatial task performance. # L2. Nature vs. Nurture ## Behavioral genetics * How genetic and environmental factors contribute to individual differences in traits. * **Link genotype** (genetic makeup) with **phenotype** (observable traits). * **Correlational methods:** shared variance (variation in genes that overlap with variance in traits). ## Heritability * The proportion of variation in a trait explained by genetic factors. ## Environmentality * The proportion of variation in a trait explained by environmental factors. * **Heritability + Environmentality = 1** ## Studies * **Familial studies:** measure correlations between relatives. * Difficult to separate shared genetics from shared environment. * Unknown degree of environmental overlap. * **Twin studies:** compare **monozygotic** (MZ) twins who share 100% of their genes (one egg split in 2) with **dizygotic** (DZ) twins who share 50% of genes (2 fertilized eggs like siblings). * Control for environmental similarity (maximizing the environmental factors). * **Adoption studies:** Examine twins separated. * Reduce environmental similarity. Are able to look at the impact of genes on traits. * Hard to account for environmental factors. ## Heritability Measures * The extent to which trait variation within a population relates to genetic variation in that population. * **Not individuals**. # L3. Piaget and Cognitive development ## Piaget's Theory of Child Development * Knowledge comes from the interaction between the child and the environment (constructivism) * Saw children as "little scientists" - child appears to be theory driven. ## Stages * **Sensorimotor (0-2):** knowledge dependent on action. * **Pre-operational (2-6):** symbolic thought and representation, egocentric. * **Concrete operational (6-11):** logical mental representation, but tied to experience. * **Formal operational (11+):** abstract logical reasoning. ## In a state of dualism * Self and word are undifferentiated. * Innate reflexes (suckling, grasping) prompt interactions with the environment. ## Construct Schemas through * **Assimilation:** integrating new info into existing schemas. * **Accommodation:** adjusting schemas to fit new information. ## Sensorimotor Development * **Object permanence:** don't realize that objects continue to exist when they are out of sight; fail to follow as an object leaves their field of vision (4-8 m.o) * By 8-12 m.o. will search for occluded object, but will make **A-not-B error** (look in initial hiding spot even if they see the object being moved to a new location). * **Symbolic thought:** by 18-24 m.o, develop mental representation. * Emergence of first words (represent objects through language). ## Egocentrism * Difficulty young children have in seeing the world from perspectives other than their own. * During pre-operational stage (2-6 y.o) * **3 mountain experiment:** physical model of 3 mountains with a teddy bear on the opposite side, asked what the teddy can see. * Young children choose the view that reflected their own perspective (fail to understand that the teddy would see something different). * Struggle to hold multiple perspectives simultaneously. * **Conservation task:** struggle to understand that certain properties (number/quantity) remain the same even when their appearance changes. * Can’t focus on both the **number** of sweets and their **density** at the same time. # L4. Evaluating Piaget ## Object permanence * Piaget believed that infants lack object permanence. * **Hood & Willatts (1986):** hiding an object by turning off the light. * Infants successfully search for the object. * They do show object permanence on easier (less complex) tasks. ## Violation of expectancy task * Shown scenarios that defy basic physics principles (i.e. trap door), infants recognize when something unexpected happens. * Infants possess a more sophisticated understanding of their environment than Piaget thought. ## Gradual development * Piaget describes development as occurring in distinct stages. * **Siegler's overlapping waves theory:** children use multiple strategies to solve problems, these strategies coexist and fluctuate over time. * Development is more gradual and quantitative than Piaget thought. * **Number conservation tasks:** Use of multiple strategies that get more advanced over time - evidence of piecemeal progress. ## Domain general vs. domain specific * Piaget saw development as domain general: the same cognitive mechanisms apply across all areas of thinking. * **Nativists (Chomsky)** believe in domain specificity: the brain has evolved specialized mechanisms for different cognitive tasks. * Certain cognitive abilities are innate and prewired into the brain. # L5. Sensation, Perception & Action ## Empiricists * Aristotle, Locke) believe that little is built in, and that organization emerges from experience. ## Nativists * (Plato, Descartes) argue that the organization is built into the system. ## Infant perception of vision * **Franz demonstrated** that infants prefer looking at patterned stimuli over plain ones - innate interest in faces and high contrast images. * **Habituation-dishabituation techniques:** Image shown repeatedly to infants until they lose interest; shown new image; renewed interest shows infant's ability to distinguish between stimuli. ## Crossmodal perception * The capacity to understand correspondences of different features in the world from different sensory modalities. * By 4 m.o, infants prefer synchronized audiovisual stimuli over non-synchronized ones. * Ability to integrate sensory information across modalities. ## Preference in taste & smell * Preference for their own mother's smell and familiar tastes experienced in utero (carrot juice experiment). * Preference for sweet ## Infant sensation * **Vision:** newborns are legally blind, vision develops rapidly. * **Audition:** hearing reaches adult level by 5-8 years old. * **Taste + smell:** amniotic fluid can take on taste that influences later food preferences in infants, mother's smell. * **Touch:** critically important for stimulating normal growth, but limited infant motor control. ## Competence vs. performance limitations * **Competence:** what a child actually knows. * **Performance:** how well they can demonstrate the knowledge. * A child might fail a Piagetian task because they struggle with the executive functions needed (ignoring distractions, hold information in working memory, inhibit an impulsive response). * Not because they lack understanding. * Failure of A-not-B task might be due to immature performance capacities rather than lack of competence. * Immature frontal lobes responsible for executive control. ## Perceptual constancies in newborns * Allows infants to recognize that objects maintain certain properties even as their appearance changes due to movement or shifts in perspective. * **Size constancy:** Slater et al (1990) familiarized newborns with a small or large cube and then showed the same cube at different distances. * Infants still recognized the size differences. * **Same for size constancies** * **Newborns show** preference for certain angles and line orientations. * **Filling for missing information:** by 6 weeks, they are able to fill in parts of an object (rod moving behind a block, they expect it to be one rod rather than small ones). * Shows early sense of perceptual continuity. ## Integration of perception + action * Innate reflexes (grasping, sucking) are triggered by sensory inputs and managed by subcortical brain structures. * **Visual cliff experiment:** Gibson and Walk (1960) showed that once an infant starts crawling, they avoid crossing an apparent "drop-off". * They perceive depth and have a fear of heights. * Crawling experience helps refine spatial understanding. * **Cross modal integration** helps improve motor abilities and understanding of causality.