45.1 – Identify three issues that have engaged developmental psychologists .

2. 45.1 – Identify three issues that have engaged developmental psychologists. Developmental Psychology: the study of human development and the changes that occur within a person’s life span. Three Major Issues in Developmental Psychology: 1) Nature/Nurture – How do genetic inheritance (nature) and experience (nurture) influence our behavior? 2) Continuity/Stages – Is development a gradual, continuous process (escalator) or a sequence of separate stages (rungs on a ladder)? 3) Stability/Change – Do our early personality traits persists through life, or do we become different persons as we age?

3. 45.2 – Discuss the course of prenatal development, and explain how teratogens affect that development. Dimensions of Early Physical Development • Conception: a single sperm (male) penetrates the outer coating of the egg (female) and fuses to form one fertilized cell. • The beginning of human development occurs when a zygote, a new cell created by the fertilization of the ovum by the sperm, is formed. The following are the stages of prenatal development: 1) Germinal Stage – zygote begins to divide into more cells (first two weeks following conception). 2) Embryonic Stage – basic life support systems (heart, nervous system, stomach, esophagus, ovaries or testes) begin to form (third through ninth weeks). 3) Fetal Stage – roughly the last seven months of prenatal development (tenth week until birth).

4. 45.2 – Discuss the course of prenatal development, and explain how teratogens affect that development. Germinal Stage • The phase encompassing the two weeks following conception • During this period… • The zygote moves towards the uterus; begins to implant in the lining • Placenta & umbilical cord begin to form • Cells begin to differentiate • ***Less than half of all zygotes survive beyond the first two weeks…

6. 45.2 – Discuss the course of prenatal development, and explain how teratogens affect that development. Embryonic Stage • The phase lasting from two weeks until the end of the second month • Once the developing organism firmly attaches to the uterus, it is called an embryo • During this period… • Major organs & structures begin to develop • By the end of this period… • Embryo is 1-inch long • Has primitive eyes, nose, lips, teeth, arms & legs • Heart beat

7. Embryo at 40 days (approximately 6 weeks) Embryo at 45 days (approximately 7 weeks)

8. 45.2 – Discuss the course of prenatal development, and explain how teratogens affect that development. Fetal Stage • The phase lasting from two months through birth • Eight weeks after fertilization the embryo becomes a fetus • During this period… • The fetus experiences tremendous growth • The muscles begin to contract • The baby moves into position

9. 45.2 – Discuss the course of prenatal development, and explain how teratogens affect that development. Critical Periods • Times during which certain environmental influences can have an impact on the development of the infant • In terms of STRUCTURAL DEVELOPMENT, most critical periods occur during the embryonic stage

11. 45.2 – Discuss the course of prenatal development, and explain how teratogens affect that development. Prenatal Risks • During prenatal development, the placenta, a protective and nutrient-filled organ, allows the fetus to mature properly by filtering out harmful substances. However, the placenta is not impermeable Certain agents can and do penetrate it, and some of them can have dire consequences for the developing fetus. The term teratogen refers to any agent that will harm the development of the fetus. Below is a list of some teratogens, as well as their known effects on development. 1) Alcohol – impaired cognitive functioning; child is more likely to become alcohol dependent later in life. -Fetal Alcohol Syndrome(FAS) – mental impairments or retardation, facial abnormalities (thin lips, pointed chin, small eyes, smaller then normal head size). 2) Smoking – underweight, premature birth, irritability, attention difficulties, possible nicotine addiction/withdrawal. 3) Cocaine – underweight, premature birth, impairment in cognitive and motor development, addiction/withdrawal.

12. 45.2 – Discuss the course of prenatal development, and explain how teratogens affect that development. Teratogenic AgentEffect on Development Rubella Blindness; deafness; heart defects; brain damage Marijuana Irritability; nervousness; tremors Cocaine Decreased height; low birth weight; respiratory problems; learning difficulties; seizures Alcohol FAS (intellectually impaired, delayed growth, facial malformation); learning difficulties; smaller than normal head size Nicotine Miscarriage; low birth weight; stillbirth; short stature; mental retardation; learning disabilities Mercury Mental retardation; blindness Syphilis Mental retardation; deafness; meningitis Caffeine Miscarriage; low birth weight Radiation Higher incidence of cancers; physical deformities Water Temperature Increased chance of neural tube defects

13. 45.2 – Discuss the course of prenatal development, and explain how teratogens affect that development.

14. 45.3 – Describe some abilities of the newborn, noting how researchers are able to identify their mental abilities. The New Baby Babies are born with many reflexes, involuntary unlearned motor skills, which are demonstrated without any outside influences. Reflexes aid in survival. These include the following: 1) Grasping/palmar – placing any object in the palm of the baby’s hand will cause the baby to grab hold of that object tightly. 2) Rooting – lightly touching/rubbing the cheek will cause the baby to turn toward that side in preparation for nursing. The baby is vigorously “rooting” for the mother’s nipple (source of nourishment). 3) Sucking – inserting an object into the baby’s mouth will cause the baby to begin the act of obtaining food. This typically follows the rooting process and involves the drawing of milk from the mother’s nipple. 4) Babinski – lightly moving a finger upward on the baby’s foot causes the toes to fan outward. 5) Swallowing – placing liquid in a baby’s mouth will elicit this reflex. 6) Stepping – baby will step when held upright (this fades after first two months and returns when baby is physiologically capable of walking, around eight months). 7) Moro – when startled or dropped, the baby will exhibit this reflex by flinging the arms outward and then inward across chest (as if it is groping for support): this reflex will disappear completely after a few months and is considered part of an earlier stage of human evolutionary development.

15. 45.3 – Describe some abilities of the newborn, noting how researchers are able to identify their mental abilities. • Habituation: decreasing responsiveness with repeated stimulation. As infants gain familiarity with repeated exposure to a visual stimulus, their interest wanes and they look away sooner. • Novelty-preference procedure – infants, like adults, focus first on the face, not on the body; we turn our heads in the direction of human voices • Sensation and Perception – newborns have personal preferences in terms of sensations and perceptions.