Developmental Psychology Part 1.A

Developmental Psychology Major Issues Details Nature/Nurture How do genetic inheritance (our nature) and experience (the nurture we receive) influence our behavior? Continuity/Stages Is development a gradual, continuous process or a sequence of separate stages? Stability/Change Do our early personality traits persist through life, or do we become different persons as we age. OBJECTIVE 8-1| State the three areas of change that developmental psychologists study, and identify the three major issues in developmental psychology. Research methods: Cross sectional and longitudinal Psychology 7e in Modules

Prenatal Development and the Newborn How, over time, did we come to be who we are? From zygote to birth, development progresses in an orderly, though fragile, sequence. Psychology 7e in Modules

Conception A single sperm cell (male) penetrates the outer coating of the egg (female) and fuse to form one fertilized cell. OBJECTIVE 8-2| Describe the union of sperm and egg at conception. Conception begins with the drop of an egg and the release of about 200 million sperm. The sperm seeks out the egg and attempts to penetrate the eggs surface. Psychology 7e in Modules

Prenatal Development Zygote – lasts 2 weeks, rapid cell division Embryo – lasts 6 weeks, organs development Fetus – 9th week to 40 weeks, placenta

Prenatal Development Once the sperm penetrates the egg, a zygote is formed. This phase lasts about two weeks and consists of rapid cell division. Less than half of all zygotes survive first two weeks. About 10 days after conception, the zygote will attach itself to the uterine wall. The outer part of the zygote becomes the placenta (which filters nutrients). OBJECTIVE 8-3| Define zygote, embryo and fetus, and explain how teratogens can affect development. Psychology 7e in Modules

Heart begins to beat and the organs begin to develop. Prenatal Development At about 14 days the zygote turns into an embryo (a and b) and is nourished by the yolk sack. Lasts about 6 weeks. Heart begins to beat and the organs begin to develop.

Prenatal Development At 9 weeks an embryo turns into a fetus and begins to gain nourishment from the placenta. The placenta is an organ which connects the fetus to the uterine wall The fetus by about the 6th month, the stomach and other organs have formed enough to survive outside of mother. At this time the baby can hear (and recognize) sounds and respond to light. Psychology 7e in Modules

Teratogens Substances that cross the placental barrier and harm the prenatal environment. They prevent the fetus from developing normally Includes: radiation, toxic chemicals, viruses, STDs, drugs, alcohol, nicotine, etc. Example: Fetal alcohol syndrome