7. The NATURE-NURTURE question asks how much nature ( genetic factors) and how much nurture ( environmental factors) contribute to a person’s biological , emotional , cognitive , personal , and social development. Prenatal Influences
11. Day One The first cell of a new human being, called a zygote, is formed when a sperm fertilizes an egg. In the egg cell shown here, the nuclei of the sperm and egg appear as two yellow-brown, irregular shapes. When these two nuclei fuse, fertilization is accomplished.
12. Day Three The zygote begins its journey down the Fallopian tube. About 36 hours after fertilization, cell division begins in the Fallopian tube, and continues to occur about twice a day. In three to four days, the cluster of dividing cells completes the 10 cm (4 in) journey through the Fallopian tube to the uterus.
13. Day Six About the fifth day after fertilization, a cluster of about a hundred cells floats in the uterus. It soon takes the form of a fluid-filled ball of cells called a blastocyst. After one or two days in the uterus, the blastocyst burrows into the uterine lining, which grows over the blastocyst and provides it with nutrients. This process is known as implantation, and the blastocyst is now called an embryo.
14. Week Four After implantation, cells of the embryo begin to specialize and form primitive organs. In the four week-old embryo shown here, the head (bottom, left) can be distinguished. The heart beats, and limb buds of the arms and legs are visible. The placenta develops at this stage and provides the embryo with nutrients from the mother. The four-week-old embryo measures about 5 mm (about 0 .2 in) from crown to rump.
15. Week Eight After eight weeks of development, all the rudimentary structures of a human have formed, and the embryo passes into the fetal stage of development. The fetus shown here floats in the watery amniotic fluid, which is contained by the transparent, tough, amniotic membrane. The amniotic fluid acts as a shock absorber, preventing damage to the developing fetus. The eight-week-old fetus measures about 30 mm (about 1.2 in) from crown to rump.
16. Development of the Human Fetus Although the total gestation period for humans lasts nine months, the fetus has a recognizable human form by the 12th week of development. The vital organs are not sufficiently developed to sustain life outside the uterus until the seventh month. While in the womb, the fetus is especially susceptible to the effects of drugs, alcohol, and x-rays.
17. Newborn Baby Newborn babies are helpless, but they can see, hear, taste, smell, and feel. They cry to let people know they need food or comfort.
20. Visual Cliff Experiment Despite his mother ’ s beckoning, an infant hesitates to cross the “ visual cliff ”— an apparently steep drop that is actually covered by transparent glass. Psychologists in the 1960s found that most infants 6 to 14 months of age were reluctant to crawl over the cliff, suggesting they had the ability to perceive depth. Most psychologists believe that the ability to perceive depth is partly innate and partly a product of early visual experience. Depth Perception
23. Developmental Milestones in Infancy Infants develop motor skills in a highly predictable sequence, but they differ in the age at which they achieve these skills. The bars in this chart show the age span at which most children reach a particular developmental milestone. Some children will attain these milestones earlier or later than the ranges shown.
24. Babies have to learn how to walk. Most begin walking by 15 months of age, although some do not begin to walk until 18 months. Then comes running and jumping !
27. Emotional Intensity Attachment between Parent and Child Attachment – refers to close fundamental emotional bonds that develop between the infant and his/her parents/caregiver. Temperament- refers to an individual differences In attention, arousal and reactivity to new or novel situations Emotional Development Temperament
28. How does attachment occur? Separation anxiety – an infant’s distress . Care & Sympathy Social Smiling Happy Greetings Crying Joy & Pleasure Delight & Satisfaction CHILD PARENT Good Parent- Child Attachment
30. Piaget’s Stages of Cognitive Development Sensori-motor Birth-2 Pre- Operational 2-7 yrs. old Formal 12 and above Concrete 7-11 yrs. old
31. Numerical Understanding in Infants Do babies have a basic ability to count? In one test of five-month-old infants, American psychologist Karen Wynn placed two Mickey Mouse dolls on a stage, hid the dolls behind a screen, then added another doll behind the screen as the infant watched. The screen was then removed to reveal two, not three, dolls. Infants in the study, like this five-month-old, stared longer at the incorrect outcome than when three dolls were revealed, indicating surprise at the outcome and suggesting that they expected to see three dolls. Some researchers interpret these findings as evidence that young infants have a simple understanding of quantity. Joe McNally Photography
32. Toddlers at Play Very young children, such as these two-year-olds, tend to play alongside one another rather than with each other. They also do not understand the concept of sharing their possessions. As children grow older, they learn to interact more with their playmates and to consider the interests of others.
33. Learning by Observation People learn much of what they know simply by observing others. Here a child learns to use a lawnmower by observing his father ’ s behavior and imitating it with a toy lawnmower.
34. Conservation of Liquid Conservation is the principle that the physical properties of an object remain the same despite changes in its appearance. In the test of conservation pictured, the child was first asked to compare identical amounts of liquid in the two short glasses. Then liquid from the middle glass was poured into the taller, skinnier glass. The child has indicated that the amounts of liquid in the two different glasses are still the same, indicating that she understands conservation. Swiss psychologist Jean Piaget believed that the ability to understand conservation marks an important developmental milestone for children.