Using your online textbook as the only resource, write an essay about each of these topics:
Explain the lifespan perspective and its assumptions about development.
Explain the issues underlying lifespan development.
Identify the historical and contemporary theories impacting lifespan development.
Compare research methods noting the advantages and disadvantages of each.
Explain ways to conduct ethical research.
Distinguish between mitosis and meiosis, genotype and phenotype, homozygous and heterozygous, and dominant and recessive.
Define behavioral genetics, describe genotype-environment correlations and genotype-environmental interactions, and define epigenetics.
Describe the changes that occur in the three periods of prenatal development.
Define teratogens and describe the factors that influence their effects. Explain maternal and paternal factors that affect the developing fetus.
Describe problems newborns experience before, during, and after birth.
While you are required to use your textbook as a resource, be careful not to simply cut, copy and paste responses from the text. I fully understand and EXPECT you to use some of the same words to explain concepts. You will not receive credit for copying content from the text (or any other source). You must demonstrate understanding by writing essays in your own words. If you quote or copy you risk not receiving credit for the entire response. If you use another person’s work, word for word, it is considered “plagiarism”.
LIFESPAN DEVELOPMENT
A Psychological Perspective Second Edition
By Martha Lally and Suzanne Valentine-French
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Lifespan Development: A Psychological Perspective Second Edition
By Martha Lally and Suzanne Valentine-French (Published 2019)
This Open Education Resource (OER) textbook was funded by a grant from the College of Lake County Foundation and supported by the Business and Social Sciences Division.
This textbook can be found at:
http://dept.clcillinois.edu/psy/LifespanDevelopment.pdf
Publication is under the following license:
Creative Commons Attribution-Noncommercial-Share Alike 3.0 unported license to view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA.
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Table of Contents
Chapter 1: Introduction to Lifespan Development Chapter 2: Heredity, Prenatal Development, and Birth Chapter 3: Infancy and Toddlerhood
Chapter 4: Early Childhood
Chapter 5: Middle and Late Childhood
Chapter 6: Adolescence
Chapter 7: Emerging and Early Adulthood
Chapter 8: Middle Adulthood
Chapter 9: Late Adulthood
Chapter 10: Death and Dying
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Table of Contents
Chapter 1: Introduction to Lifespan Development …………………………………………………………………………… 9
Lifespan Perspective ……………………………………………………………………………………………………………..10 Conceptions of Age……………………………………………………………………………………………………………….13 Periods of Development………………………………………………………………………………………………………….14 Issues in Lifespan Development ………………………………………………………………………………………………. 16 Historical Theories on Development …………………………………………………………………………………………. 17 Contemporary Theories on Development …………………………………………………………………………………… 18 Descriptive Research……………………………………………………………………………………………………………..24 Correlational Research …………………………………………………………………………………………………………..26 Experimental Research ………………………………………………………………………………………………………….. 28 Research Involving Time-Spans ………………………………………………………………………………………………. 29 Conducting Ethical Research …………………………………………………………………………………………………… 32 References………………………………………………………………………………………………………………………….. 33
Chapter 2: Heredity, Prenatal Development, and Birth…………………………………………………………………… 35
Heredity …………………………………………………………………………………………………………………………….. 35 Genotypes and Phenotypes ……………………………………………………………………………………………………..36 Genetic Disorders …………………………………………………………………………………………………………………37 Chromosomal Abnormalities……………………………………………………………………………………………………39 Behavioral Genetics ……………………………………………………………………………………………………………… 41 Prenatal Development ……………………………………………………………………………………………………………43 The Germinal Period …………………………………………………………………………………………………………….. 43 The Embryonic Period……………………………………………………………………………………………………………44 The Fetal Period……………………………………………………………………………………………………………………45 Prenatal Brain Development ……………………………………………………………………………………………………47 Teratogens………………………………………………………………………………………………………………………….. 47 Maternal Factors ………………………………………………………………………………………………………………….. 53 Prenatal Assessment………………………………………………………………………………………………………………57 Complications of Pregnancy ……………………………………………………………………………………………………59 Preparation for Childbirth ………………………………………………………………………………………………………. 60 Stages of Birth for Vaginal Delivery………………………………………………………………………………………….61 Assessing the Neonate …………………………………………………………………………………………………………… 63 Problems of the Newborn ……………………………………………………………………………………………………….63 Postpartum Maternal Concerns…………………………………………………………………………………………………65 References………………………………………………………………………………………………………………………….. 65
Chapter 3: Infancy and Toddlerhood ……………………………………………………………………………………………. 71
The Brain in the First Two Years………………………………………………………………………………………………72 Infant Sleep ………………………………………………………………………………………………………………………… 74 From Reflexes to Voluntary Movements ……………………………………………………………………………………. 77 Motor Development ……………………………………………………………………………………………………………… 78 Sensory Capacities ……………………………………………………………………………………………………………….. 79 Nutrition …………………………………………………………………………………………………………………………….82 Global Considerations and Malnutrition……………………………………………………………………………………..84 Piaget and the Sensorimotor Stage…………………………………………………………………………………………….85 Language ……………………………………………………………………………………………………………………………89 Components of Language ………………………………………………………………………………………………………. 90 Language Developmental Progression ……………………………………………………………………………………….91 Theories of Language Development…………………………………………………………………………………………..93
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Temperament………………………………………………………………………………………………………………………. 97 Infant Emotions …………………………………………………………………………………………………………………… 99 Forming Attachments ………………………………………………………………………………………………………….. 101 Erikson: Trust vs. Mistrust…………………………………………………………………………………………………….102 Mary Ainsworth and the Strange Situation Technique …………………………………………………………………. 102 Erikson: Autonomy vs. Shame and Doubt ………………………………………………………………………………… 106 Measuring Infant Development ……………………………………………………………………………………………… 106 References………………………………………………………………………………………………………………………… 106
Chapter 4: Early Childhood ……………………………………………………………………………………………………….. 115
Brain Maturation…………………………………………………………………………………………………………………116 Motor Skill Development………………………………………………………………………………………………………117 Toilet Training……………………………………………………………………………………………………………………119 Sleep………………………………………………………………………………………………………………………………..119 Sexual Development in Early Childhood…………………………………………………………………………………..120 Nutritional Concerns …………………………………………………………………………………………………………… 121 Piagets Preoperational Stage ………………………………………………………………………………………………… 123 Vygotskys Sociocultural Theory of Cognitive Development ………………………………………………………… 126 Information Processing…………………………………………………………………………………………………………127 Attention ………………………………………………………………………………………………………………………….. 127 Memory …………………………………………………………………………………………………………………………… 128 Neo-Piagetians…………………………………………………………………………………………………………………… 130 Childrens Understanding of the World…………………………………………………………………………………….131 Language Development ……………………………………………………………………………………………………….. 133 Bilingualism ……………………………………………………………………………………………………………………… 134 Preschool ………………………………………………………………………………………………………………………….135 Autism Spectrum Disorder…………………………………………………………………………………………………….136 Erikson: Initiative vs. Guilt …………………………………………………………………………………………………… 139 Self-Concept and Self-Esteem………………………………………………………………………………………………..139 Self-Control………………………………………………………………………………………………………………………. 140 Gender …………………………………………………………………………………………………………………………….. 140 Theories of Gender Development …………………………………………………………………………………………… 141 Transgender Children ………………………………………………………………………………………………………….. 142 Parenting Styles …………………………………………………………………………………………………………………. 143 Spanking ………………………………………………………………………………………………………………………….. 145 Sibling Relationships……………………………………………………………………………………………………………146 Play ………………………………………………………………………………………………………………………………… 147 Children and the Media ………………………………………………………………………………………………………..149 Child Care…………………………………………………………………………………………………………………………150 Child Abuse……………………………………………………………………………………………………………………….151 Adverse Childhood Experiences (ACEs) ………………………………………………………………………………….. 152 References………………………………………………………………………………………………………………………… 155
Chapter 5: Middle and Late Childhood ………………………………………………………………………………………. 164
Physical Development …………………………………………………………………………………………………………. 164 Sports ………………………………………………………………………………………………………………………………165 Childhood Obesity ……………………………………………………………………………………………………………… 168 Concrete Operational Thought ……………………………………………………………………………………………….170 Information Processing…………………………………………………………………………………………………………172 Language Development ……………………………………………………………………………………………………….. 174 Communication Disorders ……………………………………………………………………………………………………. 174
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Theories of Intelligence ……………………………………………………………………………………………………….. 175 Measuring Intelligence: Standardization and the Intelligence Quotient ……………………………………………… 179 Extremes of Intelligence: Intellectual Disability and Giftedness ……………………………………………………… 181 Education …………………………………………………………………………………………………………………………. 183 Cultural Differences in the Classroom………………………………………………………………………………………184 Children with Disabilities …………………………………………………………………………………………………….. 187 Children with Disabilities: Legislation …………………………………………………………………………………….. 191 Erikson: Industry vs. Inferiority………………………………………………………………………………………………193 Self-Understanding …………………………………………………………………………………………………………….. 193 Kohlbergs Stages of Moral Development ………………………………………………………………………………… 194 Friends and Peers ……………………………………………………………………………………………………………….. 196 Bullying …………………………………………………………………………………………………………………………… 199 Family Life………………………………………………………………………………………………………………………..200 References………………………………………………………………………………………………………………………… 205
Chapter 6: Adolescence ……………………………………………………………………………………………………………. 215
Growth in Adolescence…………………………………………………………………………………………………………215 Sexual Development ……………………………………………………………………………………………………………216 Adolescent Brain ………………………………………………………………………………………………………………..219 Adolescent Sleep ………………………………………………………………………………………………………………..221 Adolescent Sexual Activity……………………………………………………………………………………………………222 Eating Disorders ………………………………………………………………………………………………………………… 223 Piagets Formal Operational Stage…………………………………………………………………………………………..225 Information Processing…………………………………………………………………………………………………………227 Education …………………………………………………………………………………………………………………………. 228 School Based Preparatory Experiences ……………………………………………………………………………………. 230 Teenagers and Working ……………………………………………………………………………………………………….. 230 Teenage Drivers………………………………………………………………………………………………………………….231 Self-concept and Self-esteem in Adolescence ……………………………………………………………………………. 233 Erikson: Identity vs. Role Confusion………………………………………………………………………………………..233 Parents and Teens: Autonomy and Attachment ………………………………………………………………………….. 237 Peers ……………………………………………………………………………………………………………………………….. 238 Romantic Relationships ……………………………………………………………………………………………………….. 239 References………………………………………………………………………………………………………………………… 240
Chapter 7: Emerging and Early Adulthood ………………………………………………………………………………….. 246
Emerging Adulthood Defined ………………………………………………………………………………………………..246 Cultural Variations………………………………………………………………………………………………………………248 When Does Adulthood Begin? ………………………………………………………………………………………………. 249 Young Adults Living Arrangements ……………………………………………………………………………………….. 250 The Physiological Peak…………………………………………………………………………………………………………251 Obesity …………………………………………………………………………………………………………………………….252 A Healthy, But Risky Time……………………………………………………………………………………………………254 Gender …………………………………………………………………………………………………………………………….. 257 Sexuality ………………………………………………………………………………………………………………………….. 258 Beyond Formal Operational Thought: Postformal Thought……………………………………………………………265 Education …………………………………………………………………………………………………………………………. 266 Career Development and Employment …………………………………………………………………………………….. 268 Sexism …………………………………………………………………………………………………………………………….. 270 Temperament and Personality in Adulthood ……………………………………………………………………………… 274 Attachment in Young Adulthood ……………………………………………………………………………………………. 276
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Relationships with Parents and Siblings …………………………………………………………………………………… 279 Erikson: Intimacy vs. Isolation ………………………………………………………………………………………………. 280 Factors influencing Attraction ……………………………………………………………………………………………….. 280 Friendships ……………………………………………………………………………………………………………………….. 281 Love ……………………………………………………………………………………………………………………………….. 281 Adult Lifestyles …………………………………………………………………………………………………………………. 283 Intimate Partner Abuse ………………………………………………………………………………………………………… 291 Parenthood ……………………………………………………………………………………………………………………….. 293 References………………………………………………………………………………………………………………………… 295
Chapter 8: Middle Adulthood ……………………………………………………………………………………………………. 307
Physical Changes ……………………………………………………………………………………………………………….. 308 Sensory Changes…………………………………………………………………………………………………………………309 Health Concerns …………………………………………………………………………………………………………………311 Digestive Issues …………………………………………………………………………………………………………………. 319 Sleep………………………………………………………………………………………………………………………………..319 Exercise, Nutrition, and Weight………………………………………………………………………………………………321 Climacteric ……………………………………………………………………………………………………………………….. 324 The Climacteric and Sexuality………………………………………………………………………………………………..327 Brain Functioning ………………………………………………………………………………………………………………. 328 Crystalized versus Fluid Intelligence………………………………………………………………………………………..329 Middle Adults Returning to Education …………………………………………………………………………………….. 331 Gaining Expertise: The Novice and the Expert……………………………………………………………………………332 Work at Midlife …………………………………………………………………………………………………………………. 333 Leisure …………………………………………………………………………………………………………………………….. 336 Midlife Crisis?……………………………………………………………………………………………………………………338 Stress ………………………………………………………………………………………………………………………………. 339 Erikson: Generativity vs Stagnation ………………………………………………………………………………………… 344 Midlife Relationships ………………………………………………………………………………………………………….. 345 Middle Adult Lifestyles ……………………………………………………………………………………………………….. 348 Grandparents …………………………………………………………………………………………………………………….. 352 Friendships ……………………………………………………………………………………………………………………….. 354 Women in Midlife……………………………………………………………………………………………………………….356 Religion and Spirituality ………………………………………………………………………………………………………. 356 References………………………………………………………………………………………………………………………… 358
Chapter 9: Late Adulthood………………………………………………………………………………………………………… 371
Late Adulthood in America……………………………………………………………………………………………………371 The “Graying” of the World ………………………………………………………………………………………………….. 372 Life Expectancy vs Lifespan …………………………………………………………………………………………………. 373 Gender Differences in Life Expectancy…………………………………………………………………………………….375 Age Categories in Late Adulthood…………………………………………………………………………………………..377 Theories of Aging ………………………………………………………………………………………………………………. 380 Physical Changes of Aging …………………………………………………………………………………………………… 383 Sensory Changes in Late Adulthood ……………………………………………………………………………………….. 385 Nutrition …………………………………………………………………………………………………………………………..390 Chronic Conditions …………………………………………………………………………………………………………….. 390 Brain Functioning ………………………………………………………………………………………………………………. 394 Sleep………………………………………………………………………………………………………………………………..396 Sexuality ………………………………………………………………………………………………………………………….. 397 How Does Aging Affect Information Processing? ………………………………………………………………………. 399
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Memory …………………………………………………………………………………………………………………………… 399 Attention and Problem Solving………………………………………………………………………………………………. 401 Intelligence and Wisdom ……………………………………………………………………………………………………… 403 Neurocognitive Disorders …………………………………………………………………………………………………….. 404 Work, Retirement, and Leisure……………………………………………………………………………………………….407 Ageism …………………………………………………………………………………………………………………………….411 Living Arrangements……………………………………………………………………………………………………………412 Erikson: Integrity vs. Despair ………………………………………………………………………………………………… 414 Generativity in Late Adulthood ……………………………………………………………………………………………… 414 Social Networks in Late Adulthood ………………………………………………………………………………………… 416 Late Adult Lifestyles …………………………………………………………………………………………………………… 418 Gay and Lesbian Elders ……………………………………………………………………………………………………….. 421 Elder Abuse……………………………………………………………………………………………………………………….422 Substance Abuse and the Elderly…………………………………………………………………………………………….423 Successful Aging ……………………………………………………………………………………………………………….. 424 References………………………………………………………………………………………………………………………… 425
Chapter 10: Death and Dying……………………………………………………………………………………………………..438
Death Defined…………………………………………………………………………………………………………………….439 Most Common Causes of Death …………………………………………………………………………………………….. 440 Suicide …………………………………………………………………………………………………………………………….. 443 Fatal Drug Overdoses ………………………………………………………………………………………………………….. 446 Where do People Die? …………………………………………………………………………………………………………. 447 Developmental Perceptions of Death and Death Anxiety ……………………………………………………………… 448 Curative, Palliative, and Hospice Care …………………………………………………………………………………….. 449 Family Caregivers……………………………………………………………………………………………………………….451 Advanced Directives …………………………………………………………………………………………………………… 452 Cultural Differences in End-of-Life Decisions …………………………………………………………………………… 452 Euthanasia ………………………………………………………………………………………………………………………… 454 Religious Practices after Death……………………………………………………………………………………………….455 Green Burial ……………………………………………………………………………………………………………………… 456 Grief, Bereavement, and Mourning………………………………………………………………………………………….457 Models of Grief ………………………………………………………………………………………………………………….458 Grief: LossofChildrenandParents………………………………………………………………………………………..460 Mourning …………………………………………………………………………………………………………………………. 462 References………………………………………………………………………………………………………………………… 463
OER Attribution Information……………………………………………………………………………………………………… 467
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Chapter 1: Introduction to Lifespan Development
Developmental Psychology, also known as Human Development or Lifespan Development, is the scientific study of ways in which people change, as well as stay the same, from conception to death. You will no doubt discover in the course of studying that the field examines change across a broad range of topics. These include physical and other psychophysiological processes, cognition, language, and psychosocial development, including the impact of family and peers.
Originally concerned with infants and
children, the field has expanded to include
adolescence and more recently, aging and the
entire life span. Previously, the message was
once you are 25, your development is
essentially completed. Our academic
knowledge of the lifespan has changed, and
although there is still less research on
adulthood than on childhood, adulthood is
gaining increasing attention. This is
particularly true now that the large cohort
known as the baby boomers are beginning
to enter late adulthood. The assumption that
early childhood experiences dictate our future
is also being called into question. Rather, we
have come to appreciate that growth and
change continues throughout life and experience continues to have an impact on who we are and how we relate to others. We now recognize that adulthood is a dynamic period of life marked by continued cognitive, social, and psychological development.
You will also discover that developmental psychologists investigate key questions, such as whether children are qualitatively different from adults or simply lack the experience that adults draw upon. Other issues that they deal with is the question of whether development occurs through the gradual accumulation of knowledge or through shifts from one stage of thinking to another, or if children are born with innate knowledge or figure things out through experience, and whether development is driven by the social context or something inside each child. From the above explanation, you may be thinking already that developmental psychology is related to other applied fields. You are very right. The field informs several applied fields in psychology, including, educational psychology, psychopathology, and forensic developmental psychology. It also complements several other basic research fields in psychology including social psychology, cognitive psychology, and comparative psychology. Lastly, it draws from the theories and research of several scientific fields including biology, sociology, health care, nutrition, and anthropology.
Figure 1.1
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Learning Objectives: Lifespan Perspective
Explain the lifespan perspective and its assumptions about development.
Differentiate periods of human development.
Explain the issues underlying lifespan development
Identify the historical and contemporary theories impacting lifespan development
Lifespan Perspective
Paul Baltes identified several underlying principles of the lifespan perspective (Baltes, 1987; Baltes, Lindenberger, & Staudinger, 2006).
Development is lifelong. Lifespan theorists believe that development is life-long, and change is apparent across the lifespan. No single age period is more crucial, characterizes, or dominates human development. Consequently, the term lifespan development will be used throughout the textbook.
Development is multidirectional. Humans change in many directions. We may show gains in some areas of development, while showing losses in other areas. Every change, whether it is finishing high school, getting married, or becoming a parent, entails both growth and loss.
Development is multidimensional. We change across three general domains/dimensions; physical, cognitive, and psychosocial. The physical domain includes changes in height and weight, sensory capabilities, the nervous system, as well as the propensity for disease and illness. The cognitive domain encompasses the changes in intelligence, wisdom, perception, problem- solving, memory, and language. The psychosocial domain focuses on changes in emotion, self- perception and interpersonal relationships with families, peers, and friends. All three domains influence each other. It is also important to note that a change in one domain may cascade and prompt changes in the other domains. For instance, an infant who has started to crawl or walk will encounter more objects and people, thus fostering developmental change in the childs understanding of the physical and social world.
Development is multidisciplinary. As mentioned at the start of the chapter, human development is such a vast topic of study that it requires the theories, research methods, and knowledge base of many academic disciplines.
Development is characterized by plasticity. Plasticity is all about our ability to change and that many of our characteristics are malleable. For instance, plasticity is illustrated in the brains ability to learn from experience and how it can recover from injury.
Development is multicontextual. Development occurs in many contexts. Baltes (1987) identified three specific contextual influences.
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Normative age-graded influences: An age-grade is a specific age group, such as toddler, adolescent, or senior. Humans in a specific age-grade share particular experiences and developmental changes.
Normative history-graded influences: The time period in which you are born (see Table 1.1) shapes your experiences. A cohort is a group of people who are born at roughly the same period in a particular society. These people travel through life often experiencing similar circumstances.
Non-normative life influences: Despite sharing an age and history with our peers, each of us also has unique experiences that may shape our development. A child who loses his/her parent at a young age has experienced a life event that is not typical of the age group.
Another context that influences our lives is our social standing, socioeconomic status, or social class. Socioeconomic status (SES) is a way to identify families and households based on their shared levels of education, income, and occupation. While there is certainly individual variation, members of a social class tend to share similar lifestyles, patterns of consumption, parenting styles, stressors, religious preferences, and other aspects of daily life. All of us born into a class system are socially located, and we may move up or down depending on a combination of both socially and individually created limits and opportunities.
Families with higher socioeconomic status usually are in occupations (e.g., attorneys, physicians, executives) that not only pay better, but also grant them a certain degree of freedom and control over their job. Having a sense of autonomy or control is a key factor in experiencing job satisfaction, personal happiness, and ultimately health and well-being (Weitz, 2007). Those families with lower socioeconomic status are typically in occupations that are more routine, more heavily supervised, and require less formal education. These occupations are also more subject to job disruptions, including lay-offs and lower wages.
Poverty level is an income amount established by the federal government that is based on a set of income thresholds that vary by family size (United States Census Bureau, 2016). If a familys income is less than the government threshold, that family is considered in poverty. Those living at or near poverty level may find it extremely difficult to sustain a household with this amount of income. Poverty is associated with poorer health and a lower life expectancy due to poorer diet, less healthcare, greater stress, working in more dangerous occupations, higher infant mortality rates, poorer prenatal care, greater iron deficiencies, greater difficulty in school, and many other problems. Members of higher income status may fear losing that status, but the poor may have greater concerns over losing housing.
Table 1.1 Which generation (cohort) are you?
Generation
Baby Boomers
Millennials
Source
Born between …
1946 and 1964 1981-1996
Silent Generation
1928 and 1945
Generation X
1965 and 1980
Generation Z
1997-Present
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Today we are more aware of the
variations in development and the impact
that culture and the environment have on
shaping our lives. Culture is the totality
of our shared language, knowledge,
material objects, and behavior. It
includes ideas about what is right and
wrong, what to strive for, what to eat,
how to speak, what is valued, as well as
what kinds of emotions are called for in
certain situations. Culture teaches us
how to live in a society and allows us to
advance because each new generation
can benefit from the solutions found and
passed down from previous
generations. Culture is learned from
parents, schools, houses of worship,
media, friends and others throughout a
lifetime. The kinds of traditions and
values that evolve in a particular culture serve to help members function and value their own society. We tend to believe that our own cultures practices and expectations are the right ones. This belief that our own culture is superior is called ethnocentrism and is a normal by- product of growing up in a culture. It becomes a roadblock, however, when it inhibits understanding of cultural practices from other societies. Cultural relativity is an appreciation for cultural differences and the understanding that cultural practices are best understood from the standpoint of that particular culture.
Culture is an extremely important context for human development and understanding development requires being able to identify which features of development are culturally based. This understanding is somewhat new and still being explored. Much of what developmental theorists have described in the past has been culturally bound and difficult to apply to various cultural contexts. The reader should keep this in mind and realize that there is still much that is unknown when comparing development across cultures.
Lifespan vs. Life expectancy: At this point you must be wondering what the difference between lifespan and life expectancy is, according to developmentalists. Lifespan, or longevity, refers to the length of time a species can exist under the most optimal conditions. For instance, the grey wolf can live up to 20 years in captivity, the bald eagle up to 50 years, and the Galapagos tortoise over 150 years (Smithsonian National Zoo, 2016). The longest recorded lifespan for a human was Jean Calment who died in 1994 at the age of 122 years, 5 months, and 14 days (Guinness World Records, 2016). Life expectancy is the predicted number of years a person born in a particular time period can reasonably expect to live (Vogt & Johnson, 2016).
Figure 1.2
Source
Think of other ways culture may have affected your development. How might cultural differences influence interactions between teachers and students, nurses and patients, or other relationships?
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Conceptions of Age
How old are you? Chances are you would answer that question based on the number of years since your birth, or what is called your chronological age. Ever felt older than your chronological age? Some days we might feel like we are older, especially if we are not feeling well, are tired, or are stressed out. We might notice that a peer seems more emotionally mature than we are, or that they are physically more capable. So years since birth is not the only way we can conceptualize age.
Biological age: Another way developmental researchers can think about the concept of age is to examine how quickly the body is aging, this is your biological age. Several factors determine the rate at which our body ages. Our nutrition, level of physical activity, sleeping habits, smoking, alcohol consumption, how we mentally handle stress, and the genetic history of our ancestors, to name but a few.
Psychological age: Our psychologically adaptive capacity compared to others of our chronological age is our psychological age. This includes our cognitive capacity along with our emotional beliefs about how old we are. An individual who has cognitive impairments might be 20 years of age, yet has the mental capacity of an 8-year-old. A 70- year-old might be travelling to new countries, taking courses at college, or starting a new business. Compared to others of our age group, we may be more or less adaptive and excited to meet new challenges. Remember you are as young or old as you feel.
Social age: Our social age is based on the social norms of our culture and the expectations our culture has for people of our age group. Our culture often reminds us whether we are on target or off target for reaching certain social milestones, such as completing our education, moving away from home, having children, or retiring from work. However, there have been arguments that social age is becoming less relevant in the 21st century (Neugarten, 1979; 1996). If you look around at your fellow students in your courses at college you might notice more people who are older than the more traditional aged college students, those 18 to 25. Similarly, the age at which people are moving away from the home of their parents, starting their careers, getting married or having children, or even whether they get married or have children at all, is changing.
Those who study lifespan development recognize that chronological age does not completely capture a persons age. Our age profile is much more complex than this. A person may be physically more competent than others in their age group, while being psychologically immature. So, how old are you?
Figure 1.3 You are as young as you feel!
Source
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Periods of Development
Table 1.2 Age Periods of Development
Age Period Description
Prenatal Starts at conception, continues through implantation in the uterine wall by the embryo, and ends at birth.
Infancy and Toddlerhood
Early Childhood
Middle and Late Childhood
Adolescence
Emerging Adulthood
Early Adulthood
Middle Adulthood
Late Adulthood
Starts at birth and continues to two years of age
Starts at two years of age until six years of age
Starts at six years of age and continues until the onset of puberty
Starts at the onset of puberty until 18
Starts at 18 until 25
Starts at 25 until 40-45
Starts at 40-45 until 65
Starts at 65 onward
Table 1.2 reflects unique aspects of the various stages of childhood and adulthood that will be explored in this book. So, while both an 8-month old and an 8-year-old are considered children, they have very different motor abilities, social relationships, and cognitive skills. Their nutritional needs are different and their primary psychological concerns are also distinctive. The same is true of an 18-year-old and an 80-year-old, as both are considered adults.
Prenatal Development: Conception occurs and development begins. All of the major structures of the body are forming, and the health of the mother is of primary concern. Understanding nutrition, teratogens, or environmental factors that can lead to birth defects, and labor and delivery are primary concerns.
Infancy and Toddlerhood: The first two years of life are ones of dramatic growth and change. A newborn, with a keen sense of hearing but very poor vision, is transformed into a walking, talking toddler within a relatively short period of time. Caregivers are also transformed from someone who manages feeding and sleep schedules to a constantly moving guide and safety inspector for a mobile, energetic child.
Early Childhood: This period is also referred to as the preschool years and consists of the years which follow toddlerhood and precede formal schooling. As a two to six-year-old, the child is
Figure 1.4
Source
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busy learning language, is gaining a sense of self and greater independence, and is beginning to learn the workings of the physical world.
Middle and Late Childhood: The ages of six to the onset of puberty comprise middle and late childhood, and much of what children experience at this age is connected to their involvement in the early grades of school. Now the world becomes one of learning and testing new academic skills and by assessing ones abilities and accomplishments by making comparisons between self and others.
Adolescence: Adolescence is a period of dramatic physical change marked by an overall growth spurt and sexual maturation, known as puberty. It is also a time of cognitive change as the adolescent begins to think of new possibilities and to consider abstract concepts such as love, fear, and freedom. Ironically, adolescents have a sense of invincibility that puts them at greater risk of dying from accidents or contracting sexually transmitted infections that can have lifelong consequences.
Emerging Adulthood: The period of emerging adulthood is a transitional time between the end of adolescence and before individuals acquire all the benchmarks of adulthood. Continued identity exploration and preparation for full independence from parents are demonstrated. Although at ones physiological peak, emerging adults are most at risk for involvement in violent crimes and substance abuse.
Early Adulthood: The twenties and thirties are identified as early adulthood. Intimate relationships, establishing families, and work are primary concerns at this stage of life.
Middle Adulthood: The forties through the mid-sixties is referred to as middle adulthood. This is a period in which aging becomes more noticeable and when many people are at their peak of productivity in love and work.
Late Adulthood: Late adulthood is sometimes subdivided into two categories: The young-old who are from 65-84 years and the oldest-old who are 85 years and older. One of the primary differences between these groups is that the young-old are still relatively healthy, productive, active, and the majority continue to live independently. With both age groups the risks of diseases such as, arteriosclerosis, cancer, and cerebral vascular disease increases substantially.
Figure 1.5
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Issues in Lifespan Development
Nature and Nurture: Why are you the way you are? As you consider some of your features (height, weight, personality, being diabetic, etc.), ask yourself whether these features are a result of heredity or environmental factors, or both. Chances are, you can see the ways in which both heredity and environmental factors (such as lifestyle, diet, and so on) have contributed to these features. For decades, scholars have carried on the “nature/nurture” debate. For any particular feature, those on the side of nature would argue that heredity plays the most important role in bringing about that feature. Those on the side of nurture would argue that one’s environment is most significant in shaping the way we are. This debate continues in all aspects of human development, and most scholars agree that there is a constant interplay between the two forces. It is difficult to isolate the root of any single behavior as a result solely of nature or nurture.
Continuity versus Discontinuity: Is human development best characterized as a slow, gradual process, or is it best viewed as one of more abrupt change? The answer to that question often depends on which developmental theorist you ask and what topic is being studied. The theories of Freud, Erikson, Piaget, and Kohlberg are called stage theories. Stage theories or discontinuous development assume that developmental change often occurs in distinct stages that
are qualitatively different from each other, and in a set, universal sequence. At each stage of development, children and adults have different qualities and characteristics. Thus, stage theorists assume development is more discontinuous. Others, such as the behaviorists, Vygotsky, and information processing theorists, assume development is a more slow and gradual process known as continuous development. For instance, they would see the adult as not possessing new skills, but more advanced skills that were already present in some form in the child. Brain development and environmental experiences contribute to the acquisition of more developed skills.
Active versus Passive: How much do you play a role in your own developmental path? Are you at the whim of your genetic inheritance or the environment that surrounds you? Some theorists see humans as playing a much more active role in their own development. Piaget, for instance believed that children actively explore their world and construct new ways of thinking to explain the things they experience. In contrast, many behaviorists view humans as being more passive in the developmental process.
Figure 1.6
The tree represents continuous development, while the ladybug represents discontinuous/stage development.
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Stability versus Change: How similar are you to how you were as a child? Were you always as out-going or reserved as you are now? Some theorists argue that the personality traits of adults are rooted in the behavioral and emotional tendencies of the infant and young child. Others disagree, and believe that these initial tendencies are modified by social and cultural forces over time.
Historical Theories on Development
Preformationist View: Well into the 18th century, children were merely thought of as little adults. Preformationism, or the belief that a tiny, fully formed human is implanted in the sperm or egg at conception and then grows in size until birth, was the predominant early theory. Children were believed to possess all their sensory capabilities, emotions, and mental aptitude at birth, and as they developed these abilities unfolded on a predetermined schedule (Thomas, 1979). The environment was thought to play no role in determining development.
John Locke (1632-1704): Locke, a British philosopher, refuted
the idea of innate knowledge and instead proposed that children
are largely shaped by their social environments, especially their
education as adults teach them important knowledge. He
believed that through education a child learns socialization, or what is needed to be an appropriate member of society. Locke advocated thinking of a childs mind as a tabula rasa or blank slate, and whatever comes into the childs mind comes from the environment. Locke emphasized that the environment is especially powerful in the childs early life because he considered the mind the most pliable then. Locke indicated that the environment exerts its effects through associations between thoughts and feelings, behavioral repetition, imitation, and rewards and punishments (Crain, 2005). Lockes ideas laid the groundwork for the behavioral perspective and subsequent learning theories of Pavlov, Skinner and Bandura.
Jean-Jacques Rousseau (1712-1778): Like Locke, Rousseau also believed that children were not just little adults. However, he did not believe they were blank slates, but instead developed according to a natural plan which unfolded in different stages (Crain, 2005). He did not believe in teaching them the correct way to think, but believed children should be allowed to think by themselves according to their own ways and an inner, biological timetable. This focus on biological maturation resulted in Rousseau being considered the father of developmental psychology. Followers of Rousseaus developmental perspective include Gesell, Montessori, and Piaget.
Arnold Gesell (1880-1961): Gesell spent 50 years at the Yale Clinic of Child Development, and with his colleagues he studied the neuromotor development of children. Gesell believed that the childs development was activated by genes and he called this process maturation (Crain, 2005). Further, he believed that development unfolded in fixed sequences, and he opposed efforts to teach children ahead of schedule as he believed they will engage in behaviors when their nervous systems had sufficiently matured.
Figure 1.7
Source: A tiny person inside a sperm.
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Sigmund Freud (1856-1939): Freud was a very influential figure in the area of development. Freud emphasized the importance of early childhood experiences in shaping our personality and behavior. In our natural state, we are biological beings and are driven primarily by instincts. During childhood, however, we begin to become social beings as we learn how to manage our instincts and transform them into socially acceptable behaviors. His assumptions were that personality formed during the first few years of life. The ways in which parents or other caregivers interacted with children were assumed to have a long-lasting impact on childrens emotional states. His beliefs formed the psychodynamic perspective and his theories of psychosexual development and psychopathology dominated the field of psychiatry until the growth of behaviorism in the 1950s.
However, Freuds theory has been heavily criticized for several reasons. One is that it is very difficult to test scientifically (Crews, 1998). Freud suggested that much of what determines our actions were unknown to us, and as scientists we cannot measure these unconscious concepts. A second criticism is that Freuds case studies were not validated and cannot be used as evidence for his theories. Many later theories, particularly behaviorism and humanism, came about as challenges to Freuds views.
Contemporary Theories on Development
Erikson (1902-1994) and Psychosocial Theory: Now, let’s turn to a less controversial psychodynamic theorist, Erik Erikson. Erikson presents eight developmental stages that encompass the entire lifespan. For that reason, Eriksons psychosocial theory forms the foundation for much of our discussion of psychosocial development.
Erikson (1950) proposed a model of lifespan development that provides a useful guideline for thinking about the changes we experience throughout life. Erikson broke with Freuds emphasis on sexuality as the cornerstone of social-emotional development and instead suggested that social relationships fostered development. Erikson proposed that each period of life has a unique challenge or crisis that the person who reaches it must face, referred to as psychosocial crises. According to Erikson, successful development involves dealing with and resolving the goals and demands of each of these psychosocial crises in a positive way. These crises are usually
called stages, although that is not the term Erikson used. If a person does not resolve a stage successfully, it may hinder their ability to deal with later stages. For example, the person who does not develop a sense of trust (Eriksons first stage) may find it challenging as an adult to form a positive intimate relationship (Eriksons sixth stage). Or an individual who does not develop a clear sense of purpose and identity (Eriksons fifth stage) may become self-absorbed and stagnate rather than work toward the betterment of others (Eriksons seventh stage).
Figure 1.8
Sigmund Freud from Wikimedia
Figure 1.9
Erik Erikson
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However, most individuals are able to successfully complete the eight stages of his theory (See Table 1.3).
Table 1.3 Eriksons Psychosocial Stages
Age range
Psychosocial crisis
Positive resolution of crisis
Birth to 12 to 18 months
Trust versus Mistrust
The child develops a feeling of trust in caregivers.
18 months to 3 years
Autonomy versus Shame/Doubt
The child learns what can and cannot b e controlled and develops a sense of free will.
3 to 6 years
Initiative versus Guilt
The child learns to become independent by exploring, manipulating, and taking action.
6 to 12 years
Industry versus Inferiority
The child learns to do things well or correctly according to standards set by others, particularly in school.
12 to 18 years
Identity versus Role Confusion
The adolescent develops a well-defined and positive sense of self in relationship to others.
19 to 40 years
Intimacy versus Isolation
The person develops the ability to give and receive love and to make long-term commitments.
40 to 65 years
Generativity versus Stagnation
The person develops an interest in guiding the development of the next generation, often by becoming a parent.
65 to death
Ego Integrity versus Despair
The person develops acceptance of how one has lived.
Eriksons theory has been criticized for focusing so heavily on crises and assuming that the completion of one crisis is a prerequisite for the next crisis of development. His theory also focused on the social expectations that are found in certain cultures, but not in all. For instance, the idea that adolescence is a time of searching for identity might translate well in the middle- class culture of the United States, but not as well in cultures where the transition into adulthood coincides with puberty through rites of passage and where adult roles offer fewer choices.
Learning Theory: Also known as Behaviorism, is based on the premise that it is not p
