Chapter 3 Human Development

Prenatal Development Occurs in Three Stages Zygote stage (lasts two weeks): Embryonic stage (lasts from week 3 to week 8) Fetal stage (lasts from week 9 until birth)

Prenatal Development Occurs in Three Stages Zygote stage (lasts two weeks): –The sperm fertilizes the egg and forms a new cell—the zygote. –The zygote travels down the fallopian tubes to embed itself in the wall of the uterus.

Prenatal Development Occurs in Three Stages Embryonic stage (lasts from week 3 to week 8): When the zygote embeds itself in the uterine wall, this living tissue is called an embryo.

Prenatal Development Occurs in Three Stages Fetal stage (lasts from week 9 until birth): The last and longest stage in prenatal development in which tremendous growth occurs.

The Fetus Can Be Harmed by Parental and Environmental Factors –Parental age and maternal nutrition The ages of both the mother and the father can affect prenatal development. –Harmful environmental agents Teratogens: In Greek this word means “monster maker”—any disease, drug, or other noxious agent.

A Child’s Brain Grows at an Immense Rate The brain of an 8-month-old human fetus: Has more than twice as many neurons as an adult brain (Kolb, 1989). Produces new neurons at a rate of hundreds of thousands per minute. Early neural development results in the brain’s weight ballooning. Most added mass is due to the growth of new dendrites and the myelin sheath around axons.

Neural Network Growth During Infancy

Physical Growth and Motor Development Occur Together During year 1 the body almost triples in weight and increases in length by about one-third. In North America, infants: Lift their heads at 2 months, Sit up without support at 6 months, and Walk by the end of the first year.

Physical Growth and Motor Development Occur Together Newborns have a number of reflexes. –A reflex is an automatic, involuntary response to sensory stimuli.

Attachment Attachment: the strong emotional bond a young child forms with its primary caregiver –An important ingredient in developing attachment is receiving contact comfort.

Attachment Attachment bonds develop in stages: - 3–6 months: Clear preference for primary caregivers but do not become upset when separated from them - 7–9 months: An attachment bond forms toward a specific caregiver, and children become extremely upset following separation (separation anxiety). Children develop a fear of strangers (stranger anxiety).

Attachment –Individual differences in attachment style develop as infants interact with their parents Secure attachment: belief that one is worthy of others’ love and that people are trustworthy Insecure attachment: belief that one is unworthy of others’ love and that people are untrustworthy Securely attached children find it easier to form satisfying relationships with others than those with insecure attachment.

Influences on Attachment Style –Parenting style Parents who are responsive to their children’s emotional needs and provide sufficient contact comfort tend to foster secure attachment. –Temperament Infants with an easygoing temperament often foster positive parental reactions and these children tend to develop a secure attachment, while children with a difficult temperament may foster negative parental reactions and develop an insecure attachment. –Culture Collectivist cultures are more likely to foster secure attachment than individualist cultures.

Possible Causes of Children’s Attachment Style

Children Can Handle Parental Separation Under Certain Conditions Day care and attachment –A number of studies have found children who are in full-time daycare to tend toward less secure attachment. –However, meta-analytic research found no overall differences in attachment between children who stayed home and those who attended day care.

Children Can Handle Parental Separation Under Certain Conditions Divorce is a better predictor of adult function than attachment – A 23-year longitudinal study of more than 17,000 British infants found that parental divorce had a moderate, long-term negative impact on the mental health of about 12 percent of the children after they grew up.

Self-Concept Is the Primary Social Achievement of Childhood Self-concept: the “theory” or “story” a person constructs about herself or himself through social interaction. Self-awareness: a psychological state where an individual takes himself or herself as an object of attention. Once self-awareness develops at 18 months, a child begins to develop a self-concept.

Self-esteem Self-esteem stability: –Is relatively low during childhood, – –Increases throughout adolescence and young adulthood, and –Declines during midlife and old age.

Children Learn the “Right Way” to Think about Gender Gender is constantly changing and being redefined. –Behaviors or interests considered masculine in one culture may be defined as feminine in others.

Children Learn the “Right Way” to Think about Gender Gender identity: the knowledge that one is a male or a female and the internalization of this fact into the self-concept –Shortly after children develop self-awareness they begin to develop their gender identity. – –Gender identity is one of the basic elements in self-concept.

Erikson’s Stages Developing a sense of trust versus mistrust is the crisis of the first psychosocial stage (birth to 1 year) Developing a sense of autonomy versus shame and doubt is the crisis of the second psychosocial stage (1–2 years) Developing a sense of initiative versus guilt is the crisis of the third psychosocial stage (3–5 years)

Erikson’s Stages Developing a sense of industry vs. inferiority is the crisis of the fourth stage (6- 12 years) Developing a sense of identity versus role confusion is the crisis of the fifth stage (13– 18 years)

Erikson’s Stages Developing a sense of intimacy versus isolation is the crisis of the sixth stage (19– 45 years) Developing a sense of generativity versus stagnation is the crisis of the seventh stage (46–65 years) Developing a sense of integrity versus despair is the crisis of the eighth and last stage (66 years and up)

Piaget’s Theory of Cognitive Development - Four Stages Jean Piaget contended that cognitive development occurs as children organize their structures of knowledge to adapt to their environment. A schema is an organized cluster of knowledge that people use to understand and interpret information.

Piaget’s Theory of Cognitive Development - Four Stages Acquisition of knowledge occurs through the complementary processes of assimilation and accommodation. –Assimilation: the process of absorbing new information into existing schemas –Accommodation: the process of changing existing schemas to absorb new information

Piaget’s Stages Sensorimotor stage (birth–2 years): –experience the world through actions (grasping, looking, touching, and sucking) One of the major accomplishments at this stage is the development of object permanence. Preoperational stage (2–6 years): – represent things with words and images but having no logical reasoning

Piaget’s Stages Concrete operational stage (7–11 years): – think logically about concrete events; understanding concrete analogies and performing arithmetic operations Formal operational stage (12 years– adulthood): –develop abstract reasoning

The Three-Mountains Problem

Conservation of Liquid, Mass, and Number—Liquid

Conservation of Liquid, Mass, and Number—Mass

Conservation of Liquid, Mass, and Number—Number

Some of Piaget’s Conclusions Have Been Questioned Development may be less “stagelike” than he proposed. Children may achieve capabilities earlier than he thought. All adults may not reach formal operational thought.

Evaluating Piaget Despite criticisms, most developmental psychologists agree that Piaget has generally outlined: –An accurate view of many of the significant changes that occur in mental functioning with increasing childhood maturation; and –That children are not passive creatures merely being molded by environmental forces, but that they are actively involved in their own cognitive growth.

Vygotsky’s Theory of Cognitive Development Private speech and internalization  According to Vygotsky, learning occurs through the social instrument of language. - Children listen to people, observe their actions, and then internalize this knowledge and make it their own through private speech. Zone of proximal development  In assessing cognitive development, Vygotsky maintained that you need to identify children’s zone of proximal development (ZPD). - The ZPD is the cognitive range between what a child can do on her or his own and what the child can do with the help of adults or more-skilled children.

The Information-Processing Approach The information-processing approach contends that a number of important changes occur in children’s information- processing system that directly affect their ability to learn. The increase in information-processing speed appears to be due to the maturation of the brain.

Adolescence Adolescence, as a stage in life, is a relatively recent phenomenon. –Most societies have always viewed young people as needing instruction and time to develop. –In North American culture, the length of the adolescent period has gradually increased over the past 40 years, partly due to our society’s emphasis on attending college.

Figure 3-6 Median Age at First Marriage, United States Source: Fields, Jason. (2001). American’s families and living arrangements: March 2000 (Current Population Reports, P20-537). Washington, DC: U.S. Government Printing Office. Available online at

Heightened Self-Consciousness Is a Hallmark of Adolescence imaginary audience: belief that other people are constantly focused on their thoughts, feelings, and behavior. personal fable: the tendency for teenagers to believe that no one has ever felt or thought as they do. Despite these self-focused tendencies, in most areas of their lives, adolescents are as well adjusted as children and adults.

Parenting and Job Responsibilities Often Provide Conflicts Most adults devote tremendous time and effort to pursuing careers and/or raising children. Despite a historical shift toward gender equity: –Women are much more likely than men to receive mixed societal messages concerning their ability to juggle these dual responsibilities. –Women’s fear of conflict between occupational and family goals is less of an issue among Black women than White women.

Parenting and Job Responsibilities Often Provide Conflicts Modern society has failed to adequately encourage men to expand their responsibilities within the household. When families have actively involved and caring fathers, everyone benefits.

Certain Intellectual Abilities Increase While Others Decrease as We Age Despite the physical toll of aging, mental skills remain fully functional throughout most of adult life. Around the age of 65, some adults experience a slight decline in certain intellectual abilities.

Certain Intellectual Abilities Increase While Others Decrease as We Age Older adults’ reduced neural processing speed does not adversely affect their ability to: –Reason through everyday problems, –Understand mathematical concepts, or –Learn new information.