Human Development

1. Human Development Fundamental Issues in Developmental Psychology

2. Developmental Psychology • Basic question: What shapes the way we change over time? • Focus on psychological changes across the entire life span • Every area of psychology can be looked at from this perspective • biological development • social development • cognitive / perceptual development • personality development

3. Fundamental Issues: Nature vs. Nurture • What is role of heredity vs. environment in determining psychological makeup? • Is your IQ inherited or determined by nutrition and early environment? • Is there a ‘criminal’ gene or does poverty lead to criminal behavior? • Is sexual orientation a choice or genetically determined? • These are some of our greatest societal debates • Mistake to pose as ‘either / or’ questions

4. Fundamental Issues: Is Development Continuous? • Development means change - change can be abrupt or gradual • Two views of human development • stage theories: there are distinct phases to intellectual and personality development • continuity: development is continuous • These views have been applied to social, personal and intellectual development

5. Fundamental Issues in Developmental Psychology • Critical period - Are there periods when an individual is particularly sensitive to certain environmental experiences? • Are the first hours after birth critical for parent-child bonding? • Is first year critical for developing trust? • Easier to learn a language before age 10? • Are there individual differences in stages and critical periods?

6. Developmental Research Methods • Cross-sectional - performance of people of different age groups is compared • Longitudinal - performance of one group of people is assessed repeatedly over time • Sequential - combines cross-sectional and longitudinal approaches in a single study

7. Physical and Psychological Development Related • Physical development begins at conception • Physical maturity sets limits on psychological ability • visual system not fully functional at birth • language system not functional until much later • Prenatal environment can have lifetime influence on health and intellectual ability

8. Prenatal Development • Conception - when a sperm penetrates the ovum • Zygote - a fertilized egg • Germinal period - first two weeks after conception • Embryonic period - weeks three through eight after conception • Fetal period - two months after conception until birth

9. Prenatal Influences on Development • Teratogen - any agent that causes a birth defect (e.g., drugs, radiation, viruses) • Fetal Alcohol Syndrome (FAS) • cluster of defects occurring in infants born to mothers that drink heavily during pregnancy • leading cause of mental retardation • can be totally prevented by abstaining from alcohol during pregnancy

10. Infant Abilities and Perceptions • What does an infant feel and perceive? • William James said, “booming, buzzing confusion.” Was he right? • Is infant vision just a blur? • Is infant sound just buzzing and booming? • He was probably wrong, but infants have limited ability to communicate, so it is hard to tell what they experience

11. Infant Abilities • Infants are born with immature visual system • can detect movement and large objects • Other senses function well on day 1 • will orient to sounds • turn away from unpleasant odors • prefer sweet to sour tastes • Born with a number of reflex behaviors

12. Infant Reflexes • Rooting - turning the head and opening the mouth in the direction of a touch on the cheek • Sucking - sucking rhythmically in response to oral stimulation • Babinski - fanning and curling toes when foot is stroked

13. Infant Reflexes • Moro - throwing the arms out, arching the back and bringing the arms together as if to hold onto something (in response to loud noise or sudden change in position of the head) • Grasping - curling the fingers around an object

14. Methods for Studying Infants • Infant reflexes provide insight into their mental life • gaze duration related to visual perception • head turning related to auditory attention • sucking, reaching, kicking can be used to measure interest

15. Infant Perception • Not just a blur or a buzz • In first week • will recognize their mother’s smell • will show preference for novel stimuli • gaze at face-like pattern rather than similar non face-like pattern

16. Infant Perception • Infants explore their environment in whatever way their physical development permits • At 2-3 months will grasp object and put in mouth to explore • At 3-4 months will manipulate object, examine it visually, selectively attend to novel objects or events

17. Infant Perception • A basic question is how knowledge of the properties of physical objects arises • object permanence • objects can’t pass through other objects • dropped objects fall • Research on infant selective attention • measure gaze duration • create physically impossible events • infants notice at 3-4 months • Depth perception- visual cliff

18. Summary • Developmental psychology concerned with psychological change over the life span • Issues are very broad • heredity vs. environment • stages vs. continuous change • Are there critical periods? • prenatal influences • How much ability are we born with?