Research MethodologiesResearch Methodologies

• cross-sectional:cross-sectional: Examining groups Examining groups of subjects who are of different ages.of subjects who are of different ages.

• longitudinal:longitudinal: Examining the same Examining the same group of subjects two or more times group of subjects two or more times as they age.as they age.

• biographical:biographical: Studying Studying developmental changes by developmental changes by reconstructing subjects’ past through reconstructing subjects’ past through interviews and investigating the interviews and investigating the effects of past events on current effects of past events on current behaviors.behaviors.

Cross-Sectional StudiesCross-Sectional Studies

AdvantagesAdvantages• inexpensiveinexpensive• relatively quick relatively quick

to completeto complete• no high attrition no high attrition

raterate

DisadvantagesDisadvantages• different age different age

groups may be groups may be dissimilardissimilar

• age and maturity age and maturity may not be may not be equivalentequivalent

• confounds confounds cohort and age cohort and age differencesdifferences

Longitudinal StudiesLongitudinal Studies

AdvantagesAdvantages• detailed info. detailed info.

about subjectsabout subjects• provides great provides great

detail of detail of developmental developmental changeschanges

• follows same follows same cohort groupscohort groups

DisadvantagesDisadvantages• expensive and expensive and

time-consumingtime-consuming• potential for potential for

high attrition high attrition ratesrates

• may confound may confound age differences age differences & differences in & differences in assessment toolsassessment tools

Biographical StudiesBiographical Studies

AdvantagesAdvantages• rich detail about rich detail about

one individual’s one individual’s lifelife

• allows for in-allows for in-depth study of depth study of one individualone individual

DisadvantagesDisadvantages• individual’s individual’s

recall is often recall is often untrustworthyuntrustworthy

• can be very can be very time-consuming time-consuming and expensiveand expensive

Prenatal DevelopmentPrenatal Development

• prenatal development:prenatal development: Development from conception to Development from conception to birth.birth.

• embryo:embryo: 2 weeks after conception 2 weeks after conception to 3 months.to 3 months.

• fetus:fetus: 3 months after conception 3 months after conception to birth.to birth.

Importance of the Importance of the PlacentaPlacenta

• The organ by which an embryo or The organ by which an embryo or fetus is attached to its mother’s fetus is attached to its mother’s uterus and that nourishes it during uterus and that nourishes it during prenatal development.prenatal development.

• The effects of alcohol and The effects of alcohol and smoking by the mother readily smoking by the mother readily cross the placenta.cross the placenta.

Fetal Alcohol Syndrome Fetal Alcohol Syndrome (FAS)(FAS)

• Heavy alcohol consumption by Heavy alcohol consumption by the mother during pregnancy the mother during pregnancy results in facial deformities, heart results in facial deformities, heart defects, stunted growth, and defects, stunted growth, and cognitive impairments.cognitive impairments.

Neonate ReflexesNeonate Reflexes

• rooting reflex:rooting reflex: A baby turns its A baby turns its head toward something touching head toward something touching its cheek and gropes around with its cheek and gropes around with its mouth.its mouth.

• sucking reflex:sucking reflex: Sucking on any Sucking on any object placed in a baby’s mouth.object placed in a baby’s mouth.

• swallowing reflex:swallowing reflex: Enables the Enables the neonate to swallow liquids neonate to swallow liquids without choking.without choking.

Neonate ReflexesNeonate Reflexes

• grasping reflex:grasping reflex: Neonates close Neonates close their fists on anything that is their fists on anything that is placed in their hands.placed in their hands.

• stepping reflex:stepping reflex: The light The light stepping motions made by stepping motions made by neonates if they are held upright neonates if they are held upright with their feet just touching a with their feet just touching a surface.surface.

TemperamentTemperament

The physical/emotional The physical/emotional characteristics of the characteristics of the newborn child and young newborn child and young infant.infant.

3 Types of Temperaments 3 Types of Temperaments (Thomas & Chess)(Thomas & Chess)

• easy:easy: good-natured and adaptable, good-natured and adaptable, easy to care for and pleaseeasy to care for and please

• difficult:difficult: moody and intense, moody and intense, reacting to new people and new reacting to new people and new situations negatively and stronglysituations negatively and strongly

• ““slow-to-warm-up”:slow-to-warm-up”: relatively relatively inactive and slow to respond to inactive and slow to respond to new things, and when they do new things, and when they do react, their reactions are mildreact, their reactions are mild

Visual Preferences of Visual Preferences of InfantsInfants

• novel picture or patternnovel picture or pattern

• picture/pattern with clear picture/pattern with clear contrasts (e.g., black and white contrasts (e.g., black and white patterns) patterns)

• their own mother rather than a their own mother rather than a strangerstranger

Depth Perception (Visual Depth Perception (Visual Cliff Studies)Cliff Studies)

• Crawling babies will not cross Crawling babies will not cross over onto deep side.over onto deep side.

• babies too young to crawl: no babies too young to crawl: no anxiety, but do demonstrate depth anxiety, but do demonstrate depth perceptionperception

• 2-4 months old: begin to 2-4 months old: begin to perceive patterns, objects, and perceive patterns, objects, and depthdepth

Developmental TrendsDevelopmental Trends

• cephalocaudal:cephalocaudal: Development Development occurs in areas near the head occurs in areas near the head (cephalo) first and areas farther (cephalo) first and areas farther from the head develop later from the head develop later ((caudalcaudal means tail). means tail).

• proximodistal:proximodistal: Development Development occurs near the center of the body occurs near the center of the body ((proximalproximal) first and near the ) first and near the extremities (extremities (distaldistal) later.) later.

Developmental TrendsDevelopmental Trends

• gross to specific development:gross to specific development: Children tend to gain control of Children tend to gain control of gross (large muscle) movement gross (large muscle) movement before they gain control of before they gain control of specific (or fine motor control) specific (or fine motor control) movement.movement.

Cognitive Development Cognitive Development (Piaget)(Piaget)

• sensory-motor stage (birth-2)sensory-motor stage (birth-2)

• preoperational stage (2-7)preoperational stage (2-7)

• concrete operations (7-11)concrete operations (7-11)

• formal operations (11-15)formal operations (11-15)

Sensory-Motor Stage Sensory-Motor Stage (birth to 2 years)(birth to 2 years)

• object permanence:object permanence: The concept The concept that things continue to exist even that things continue to exist even when they are out of sight.when they are out of sight.

• mental representations:mental representations: Mental Mental images or symbols (such as images or symbols (such as words) used to think about or words) used to think about or remember an object, a person, or remember an object, a person, or an event.an event.

Preoperational Stage Preoperational Stage (2 to 7 years)(2 to 7 years)

• A child becomes able to use A child becomes able to use mental representations and mental representations and language to describe, remember, language to describe, remember, and reason about the world.and reason about the world.

• egocentric:egocentric: Unable to see things Unable to see things from another person’s point of from another person’s point of view.view.

Concrete-Operational Concrete-Operational Stage (7 to 11 years)Stage (7 to 11 years)

• A child can attend to more than A child can attend to more than one thing at a time and one thing at a time and understand someone else’s point understand someone else’s point of view, though thinking is of view, though thinking is limited to concrete matters.limited to concrete matters.

• A child can understand A child can understand conservationconservation..

Principles of ConservationPrinciples of Conservation

The concept that basic The concept that basic amounts remain constant amounts remain constant despite superficial changes despite superficial changes in appearances.in appearances.

Formal-Operational Stage Formal-Operational Stage (11 to 15 years)(11 to 15 years)

The individual becomes The individual becomes capable of abstract capable of abstract thought.thought.

Criticisms of Piaget’s Criticisms of Piaget’s TheoryTheory

• Piaget underestimated the Piaget underestimated the cognitive ability of infants.cognitive ability of infants.

• Cognitive milestones are reached Cognitive milestones are reached sooner than Piaget believed.sooner than Piaget believed.

• He did not take the role of social He did not take the role of social interaction into account.interaction into account.

• His theory does not address His theory does not address human diversity.human diversity.