Research Methodologies cross-sectional: Examining groups of subjects who are of different ages.cross-sectional: Examining groups of subjects who are of different ages. longitudinal: Examining the same group of subjects two or more times as they age.longitudinal: Examining the same group of subjects two or more times as they age. biographical: Studying developmental changes by reconstructing subjects’ past through interviews and investigating the effects of past events on current behaviors.biographical: Studying developmental changes by reconstructing subjects’ past through interviews and investigating the effects of past events on current behaviors.

Cross-Sectional Studies Advantages inexpensiveinexpensive relatively quick to completerelatively quick to complete no high attrition rateno high attrition rateDisadvantages different age groups may be dissimilardifferent age groups may be dissimilar age and maturity may not be equivalentage and maturity may not be equivalent confounds cohort and age differencesconfounds cohort and age differences

Longitudinal Studies Advantages detailed info. about subjectsdetailed info. about subjects provides great detail of developmental changesprovides great detail of developmental changes follows same cohort groupsfollows same cohort groupsDisadvantages expensive and time-consumingexpensive and time-consuming potential for high attrition ratespotential for high attrition rates may confound age differences & differences in assessment toolsmay confound age differences & differences in assessment tools

Biographical Studies Advantages rich detail about one individual’s liferich detail about one individual’s life allows for in- depth study of one individualallows for in- depth study of one individualDisadvantages individual’s recall is often untrustworthyindividual’s recall is often untrustworthy can be very time-consuming and expensivecan be very time-consuming and expensive

Prenatal Development prenatal development: Development from conception to birth.prenatal development: Development from conception to birth. embryo: 2 weeks after conception to 3 months.embryo: 2 weeks after conception to 3 months. fetus: 3 months after conception to birth.fetus: 3 months after conception to birth.

Importance of the Placenta The organ by which an embryo or fetus is attached to its mother’s uterus and that nourishes it during prenatal development.The organ by which an embryo or fetus is attached to its mother’s uterus and that nourishes it during prenatal development. The effects of alcohol and smoking by the mother readily cross the placenta.The effects of alcohol and smoking by the mother readily cross the placenta.

Fetal Alcohol Syndrome (FAS) Heavy alcohol consumption by the mother during pregnancy results in facial deformities, heart defects, stunted growth, and cognitive impairments.Heavy alcohol consumption by the mother during pregnancy results in facial deformities, heart defects, stunted growth, and cognitive impairments.

Neonate Reflexes rooting reflex: A baby turns its head toward something touching its cheek and gropes around with its mouth.rooting reflex: A baby turns its head toward something touching its cheek and gropes around with its mouth. sucking reflex: Sucking on any object placed in a baby’s mouth.sucking reflex: Sucking on any object placed in a baby’s mouth. swallowing reflex: Enables the neonate to swallow liquids without choking.swallowing reflex: Enables the neonate to swallow liquids without choking.

Neonate Reflexes grasping reflex: Neonates close their fists on anything that is placed in their hands.grasping reflex: Neonates close their fists on anything that is placed in their hands. stepping reflex: The light stepping motions made by neonates if they are held upright with their feet just touching a surface.stepping reflex: The light stepping motions made by neonates if they are held upright with their feet just touching a surface.

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

3 Types of Temperaments (Thomas & Chess) easy: good-natured and adaptable, easy to care for and pleaseeasy: good-natured and adaptable, easy to care for and please difficult: moody and intense, reacting to new people and new situations negatively and stronglydifficult: moody and intense, reacting to new people and new situations negatively and strongly “slow-to-warm-up”: relatively inactive and slow to respond to new things, and when they do react, their reactions are mild“slow-to-warm-up”: relatively inactive and slow to respond to new things, and when they do react, their reactions are mild

Visual Preferences of Infants novel picture or patternnovel picture or pattern picture/pattern with clear contrasts (e.g., black and white patterns)picture/pattern with clear contrasts (e.g., black and white patterns) their own mother rather than a strangertheir own mother rather than a stranger

Depth Perception (Visual Cliff Studies) Crawling babies will not cross over onto deep side.Crawling babies will not cross over onto deep side. babies too young to crawl: no anxiety, but do demonstrate depth perceptionbabies too young to crawl: no anxiety, but do demonstrate depth perception 2-4 months old: begin to perceive patterns, objects, and depth2-4 months old: begin to perceive patterns, objects, and depth

Developmental Trends cephalocaudal: Development occurs in areas near the head (cephalo) first and areas farther from the head develop later (caudal means tail).cephalocaudal: Development occurs in areas near the head (cephalo) first and areas farther from the head develop later (caudal means tail). proximodistal: Development occurs near the center of the body (proximal) first and near the extremities (distal) later.proximodistal: Development occurs near the center of the body (proximal) first and near the extremities (distal) later.

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

Cognitive Development (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 (birth to 2 years) object permanence: The concept that things continue to exist even when they are out of sight.object permanence: The concept that things continue to exist even when they are out of sight. mental representations: Mental images or symbols (such as words) used to think about or remember an object, a person, or an event.mental representations: Mental images or symbols (such as words) used to think about or remember an object, a person, or an event.

Preoperational Stage (2 to 7 years) A child becomes able to use mental representations and language to describe, remember, and reason about the world.A child becomes able to use mental representations and language to describe, remember, and reason about the world. egocentric: Unable to see things from another person’s point of view.egocentric: Unable to see things from another person’s point of view.

Concrete-Operational Stage (7 to 11 years) A child can attend to more than one thing at a time and understand someone else’s point of view, though thinking is limited to concrete matters.A child can attend to more than one thing at a time and understand someone else’s point of view, though thinking is limited to concrete matters. A child can understand conservation.A child can understand conservation.

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

Formal-Operational Stage (11 to 15 years) The individual becomes capable of abstract thought.

Criticisms of Piaget’s Theory Piaget underestimated the cognitive ability of infants.Piaget underestimated the cognitive ability of infants. Cognitive milestones are reached sooner than Piaget believed.Cognitive milestones are reached sooner than Piaget believed. He did not take the role of social interaction into account.He did not take the role of social interaction into account. His theory does not address human diversity.His theory does not address human diversity.