Chapter 8 - Human Development

LO 18 Explain some of the socioemotional changes that occur across adulthood.

According to Erikson, during young adulthood, people face the crisis of intimacy versus isolation, and failure to create meaningful, deep relationships may lead to a life of isolation. In middle adulthood, we face the crisis of generativity versus stagnation. Positive resolution of this stage includes feeling like one has made a valuable impact on the next generation. In late adulthood, in the crisis of integrity versus despair, we look back on life and evaluate how we have done.

LO 11 Explain Erikson's theory of psychosocial development up until puberty.

According to Erikson, human development is marked by eight psychosocial stages, spanning infancy through old age. Each stage is marked by a developmental task or an emotional crisis that must be handled successfully to allow for healthy psychological growth: trust versus mistrust, autonomy versus shame and doubt, initiative versus guilt, and industry versus inferiority are the stages up to puberty.

LO 12 Give examples of significant physical changes that occur during adolescence.

Adolescence is characterized by many physical changes: a growth spurt in height, weight, and bones; sex hormones, which influence this growth and development, are also at high levels. In addition, primary sex characteristics (features associated with reproductive organs) and secondary sex characteristics (features not associated with reproductive organs) mature in both boys and girls.

LO 16 Name several of the most important physical changes that occur across adulthood.

Adulthood brings about many physical changes. We are physically at our peak in early adulthood, but that typically declines as we reach late adulthood. Gradual physical changes occur, including hearing and vision loss, wrinkles, graying hair, reduced stamina, and for women menopause. Lifestyle choices can have significant influences on health. Heavy drinking, drug use, poor eating habits, and sleep deprivation can make one look, feel, and function like someone much older.

LO 4 Examine the role genes play in our development and identify the biological factors that determine sex.

All the cells in the human body (except for red blood cells) include a nucleus at their center. Inside this nucleus are our chromosomes, which contain genes made of deoxy-ribonucleic acid (DNA). Genes provide the blueprint for our physiological development and structure, the inherited framework for how we will develop. At conception, when the sperm and egg merge, they form a single cell called a zygote. The 23rd pair of chromosomes, also referred to as the sex chromosomes, provides specific instructions for the individual to develop into a female or male. The egg from the mother contributes an X chromosome to the 23rd pair, and the sperm from the father contributes either an X chromosome or a Y chromosome. When both members of the 23rd pair are X chromosomes (XX), the zygote generally develops into a female. When the 23rd pair contains an X chromosome and a Y chromosome (XY), the zygote generally develops into a male.

LO 7 Summarize the physical changes that occur in infancy.

As newborns grow, they experience astounding changes both seen and unseen. We see advancement in demonstrated capabilities, known as the motor milestones, and an increasingly sophisticated ability to discriminate among sensory stimuli. These sensorimotor advancements are made possible by the incredible brain development that is occurring. Neurons rapidly sprout new connections, and this dramatic synaptic growth is influenced by experiences and stimulation from the environment.

LO 9 Outline the universal sequence of language development.

At age 2-3 months, infants typically start to produce vowel-like sounds known as cooing. At 4-6 months, in the babbling stage, infants combine consonants with vowels. This progresses to their first words around 12 months, followed by two-word telegraphic speech at approximately 18 months. As children mature, they start to use more complete sentences. A "vocabulary explosion" tends to occur around 2 to 3 years of age. Most children are fluent in their native language by age 5 or 6.

LO 6 Describe the progression of prenatal development.

At the moment of conception, an egg from the mother and sperm cell from father come together to form a zygote. Under normal circumstances, the zygote immediately begins to divide into two cells, then each of those cells divides, and so on. During the germinal period, the zygote grows through cell division and eventually becomes implanted in the uterine wall. Between the 3rd and 8th weeks of development, the mass of cells is called an embryo. From 2 months following conception to birth, the growing human is identified as a fetus. The amniotic sac serves as a protective barrier; however, harmful environmental agents called teratogens can damage the growing embryo or fetus. Radiation, viruses, bacteria, chemicals, alcohol, and drugs are all considered teratogens.

LO 17 Identify the most significant cognitive changes that occur across adulthood.

Cognitive ability remains stable from early to middle adulthood, but midlife is a time when information processing and memory can decline, particularly the ability to remember past events. Processing speed may slow with old age. Crystallized intelligence refers to the knowledge we gain through experience, and fluid intelligence refers to the ability to think in the abstract and create associations among concepts. As we age, the speed with which we learn new material and create associations decreases, but crystallized intelligence increases.

LO 1 Define human development

Development refers to the changes that occur in physical, cognitive, and socioemotional functioning over the course of the life span. These changes begin at conception and end at death. The goal of developmental psychology is to examine such changes.

LO 3 Identify the types of research psychologists use to study developmental processes.

Developmental psychologists use several methods to explore changes across the life span. The cross-sectional method examines people of different ages at one point in time, and the longitudinal method follows one sample of individuals over a period of time. In the cross-sequential method, participants are divided into age groups as well as followed over time, so researchers can examine developmental changes within individuals and across different age groups.

LO 2 Outline the three longstanding discussions in developmental psychology.

Developmental psychologists' longstanding debates and discussions have centered on three major themes: stages and continuity; nature and nurture; and stability and change. Each of these themes relates to a basic question: (1) Does development occur in separate or discrete stages, or is it a steady, continuous process? (2) What are the relative roles of heredity and environment in human development? (3) How stable is one's personality over a lifetime and across situations?

LO 13 Summarize Piaget's description of cognitive changes that take place during adolescence.

During the formal operational stage of cognitive development, adolescents begin to use deductive reasoning and logic to draw conclusions. A specific type of egocentrism also emerges in adolescence. Adolescents may believe that most of their peers think the same way they do. Because they have not had a lot of life experiences, they may fail to consider long-term consequences associated with their behaviors.

LO 5 Discuss how genotype and phenotype relate to development.

Genotype refers to the 23 chromosome pairs that are unique to each individual and do not change in response to the environment. The genotype interacts with the environment, which results in a phenotype. This phenotype consists of a person's unique physical, psychological, and behavioral characteristics resulting from his or her particular combination of genotype and experiences.

LO 15 Examine Kohlberg's levels of moral development.

Kohlberg proposed three levels of moral reasoning that occur in sequence. Preconventional moral reasoning usually applies to young children and focuses on the personal consequences of behaviors, both good and bad. At puberty, conventional moral reasoning is used, with the determination of right and wrong based on the expectations of society and important others. In postconventional moral reasoning, right and wrong are determined by the individual's beliefs about morality, which may not coincide with society's rules and regulations.

LO 19 Describe Kübler-Ross' theory regarding reactions to imminent death.

Kübler-Ross documented similar reactions among people faced with the news of their imminent death: denial (reacting with shock and disbelief), anger (toward others who are healthy, or about the lack of a cure), bargaining (negotiating for more time), depression (due to illness or the overwhelming sense of loss), and acceptance (accepting death is inevitable). Yet people vary greatly in how they deal with and experience dying. Many of these reactions or coping mechanisms may occur simultaneously or in stages, or the dying individual might not experience any of these stages.

LO 10 Discuss the key elements of Piaget's and Vygotsky's theories of cognitive development.

Piaget proposed that one important component of cognition is the schema, the collection of ideas or notions that serve as a building block of understanding. Humans are driven to advance intellectually, partly as a result of an innate need to maintain cognitive equilibrium. With assimilation, we understand new information using an already existing schema. With accommodation, we restructure old notions to make a place for new information. Piaget proposed that cognitive development occurs in four stages: sensorimotor, preoperational, concrete operational, and formal operational. Vygotsky was interested in how social and cultural factors affect cognitive development. He proposed that one way to help children's cognitive development is through scaffolding—pushing them to go just beyond what they are competent and comfortable doing, but also providing help, when needed, in a decreasing manner.

LO 8 Distinguish among the theories explaining language acquisition.

The behaviorist's view of language development proposes that infants and children learn language in the same way they learn everything else—through positive attention from others for correct behavior, unpleasant attention for incorrect behavior, and their own observations. Chomsky suggested that humans have a language acquisition device (LAD), an innate mechanism that provides a framework for children to learn language. Infant-directed speech (IDS) also plays a role in language acquisition. Infants pay more attention to adults who use IDS. These same adults are more likely to provide them with chances to learn and interact, thus allowing more exposure to language.

LO 14 Detail how Erikson explained changes in identity during adolescence.

The stage of ego identity versus role confusion occurs during adolescence and is marked by the creation of an adult identity. During this stage, the adolescent seeks to define himself through his values, beliefs, and goals. Erikson believed that the period of role confusion is important for the adolescent to navigate, as it provides a chance to "try out" different roles. Successful resolution of this stage results in stronger fundamental values, beliefs, and goals with a firmer sense of identity.