Chapter 9: Human Development I
Chapter Summary

I.STUDYING DEVELOPMENT - Developmental psychology is the study of age-related changes in behavior. The field emphasizes maturation, early experiences, and various stages throughout the life span.

A.Theoretical Issues – The three most important issues guiding research in human development are: nature versus nurture, continuity versus stages, and stability versus change. This issue has been an on-going debate that dates back to the ancient Greeks. Psychologists today prefer the biopsychosocial model.

B.Research Methods – To study development researchers use the cross-sectional and longitudinal Approaches. Each method has its own advantages and disadvantages.

Gender and Cultural Diversity: Cultural Psychology’s Guidelines for Developmental Research - Cultural psychologists have suggested that developmental researchers should be guided by four points: 1) culture may be the most important determinant of development; 2) human development, like most areas of psychology, cannot be studied outside its sociocultural context; 3) culture is largely invisible to its participants; and 4) each culture's ethnotheories are important determinants of behavior.

II.PHYSICAL DEVELOPMENT

A.Prenatal and Early Childhood - Physical development in prenatal and early childhood are a time of rapid change. The prenatal period of development consists of three major stages: the germinal period, the embryonic period, and the fetal period. Physical development is often affected by environmental influences. Poor prenatal nutrition is a leading cause of birth defects, and most drugs (both prescription and over-the-counter) are potentially teratogenic (capable of producing birth defects). Doctors advise pregnant women to avoid all unnecessary drugs, especially nicotine and alcohol. During the prenatal period and the first year of life, the brain and nervous system grow faster than all other parts of the body. Early motor development (crawling, standing, and walking) is largely the result of maturation. Contrary to earlier beliefs, psychologists now know that the sensory and perceptual abilities of newborns are relatively well developed.

B.Adolescence and Adulthood - The rapid changes that occur during adolescence are discussed, including secondary sexual characteristics, physical changes, and psychological adjustments. At puberty, adolescents become capable of reproduction (the female menarche and the male spermarche). They also experience a sharp increase in height, weight, and skeletal growth as a result of the pubertal growth spurt. During middle age, both men and women experience significant body changes—menopause and the male climacteric. After middle age, most physical changes are gradual and occur in the heart, arteries, brain, and sensory receptors. Although many of these changes (such as decreases in cardiac output and visual acuity) are the result of primary aging, others are the result of abuse, disuse, and disease—secondary aging. Physical aging may be genetically built-in from the moment of conception (programmed theories), or it may result from the body's inability to repair damage (wear-and-tear) theories. Recent research shows that cognitive functioning in older adults can be greatly enhanced with simple aerobic training.

III.COGNITIVE DEVELOPMENT - Jean Piaget, perhaps more than any other researcher, has demonstrated the unique cognitive processes of children. He believed that children are driven toward knowledge because of their biological need for adaptation to the environment. During adaptation, the child uses schemas (mental patterns or blueprints) to interpret the world. Sometimes new information can be assimilated into the existing schemas, but on other occasions the existing schemas must be modified, which calls for accommodation.

A.Stages of Cognitive Development - The work of Jean Piaget as the primary figure in studying cognitive development is covered in some detail. Each of the four stages of cognitive development—sensorimotor (birth to 2 years), preoperational (2-7 years), concrete operational (7-11 years), and formal operational (11 and beyond)—are introduced. The sensorimotor stage is characterized by the acquisition of object permanence—the realization that objects (or people) continue to exist even when out of sight. During the preoperational stage, children are better equipped to use symbols, but their thinking is also egocentric and animistic. The concrete operational stage is characterized by the acquisition of operations, such as, reversibility and conservation, and increased logic. During the formal operational stage, the adolescent is able to think abstractly and deal with hypothetical situations.

Critical Thinking/Active Learning: Developing Insight into Egocentricity – Piaget’s concept of egocentricism is highlighted by including an egocentricity rating scale to heighten self-awareness of personal egocentricism.

B.Assessing Piaget's Theory - Although Piaget has been criticized for underestimating abilities, as well as educational and cultural influences, he remains one of the most respected psychologists of modern times.

C.Information Processing – An alternative to Piaget’s theory of cognitive development is the information processing model which compares the mind to a computer. Psychologists who explain cognitive development in terms of information processing have found this model especially helpful in explaining attention and memory.

IV.SOCIAL-EMOTIONAL DEVELOPMENT – Along with physical and language development, developmental psychologists are interested in social-emotional development, how humans become “entire” with the help of other human beings.

A.Attachment – The classic studies of Bowlby, Lorenz, and Harlow’s study of contact comfort in monkeys are presented. Infants arrive in this world with behaviors that encourage a strong bond of attachment with primary caregivers, from the major one between mother and child to fathers, grandparents, and other caretakers. In studying attachment, researchers are often divided along that now familiar line of nature versus nurture. Ainsworth found that the following levels of attachment: securely attached, avoidant, or anxious/ambivalent affect long-term behaviors. And, although early attachment experiences may predict the future, they do not determine it.

Research Highlight: Romantic Love and Attachment - Using the levels of attachment, researchers have studied the relationship between an infant’s attachment to a parent figure and discovered parallels in an adult’s love for a romantic partner.

B.Parenting Styles – Three different methods of child rearing (Baumrind 1980, 1995) are presented and evaluated: (1) Authoritarian, (2) Permissive, and (3) Authoritative.