Developmental psychology summary
Chapter 1
Lifespan development, the scientific study of human growth throughout life, is a hybrid latecomer to psychology. Its roots lie in child
development, the study of childhood and the teenage years. Child development traces its origins back more than a century. In 1877,
Charles Darwin published an article based on notes he had made about his baby during the first years of life. In the 1890s, Stanley
Hall established the first institute in the United States devoted to research on the child. The field of child development began to take
off between World Wars I and II. Gerontology, the scientific study of aging had a slower start. Researchers began to really study the
aging process only after World War II. Gerontology and its related field, adult development, underwent their phenomenal growth
spurt during the final third of the twentieth century. Lifespan development puts it all together forming a huge mega-discipline:
• Lifespan development is multidisciplinary. It draws on fields as different as neuroscience, nursing, psychology, and social policy to
understand every topic relating to human development.
• Lifespan development explores the predictable milestones on our human journey
• Lifespan development focuses on the individual differences that give spice to human life, Developmentalists want to understand
what causes the striking individual differences we see in temperament, talents, and traits. They are interested in exploring individual
differences in the timing examining why people reach puberty earlier or later or age more quickly or slowly than their peers.
• Lifespan development explores the impact of life transitions and practices. It deals with normative, or predictable, transitions, such
as retirement, becoming parents, or beginning middle school. It focuses on non- normative, or atypical, transitions, such as divorce,
the death of a child, or how the recent declines in the economy affect how we are approaching the world. It explores more enduring
life practices, such as smoking, spanking, or sleeping in the same bed with your child. Life transitions that we consider normative,
such as retiring or starting middle school, are products of living in a particular time in history. They understand that life practices
such as smoking or spanking or sleeping in bed with a child vary, depending on our social class and cultural background.
What is developmental psychology?
Narrow conception of development
• Sequential – based on several stages/ levels/ phases
• Unidirectional - earlier changes are prerequisite for later ones
• End state - higher value than the original state
• Irreversible in progression
• Qualitative - structural transformations
• Biological growth - independent of culture
• Universal - the same for all humans
Developmental psychology: Definition
▪ Developmental Psychology deals with behavioral changes within persons across the lifespan, and with differences between and
similarities among persons in the nature of these changes.
▪ Its aim is not only to describe these intraindividual changes and interindividual differences but also to explain how they come about
and to find ways to modify them in an optimum way.
What develops when, how, and why?
Typical question for developmental psychologists
• What can you expect from an infant, a primary school child, a teenager, an adult and an older adult?
• Which competences, attitudes and interests can be expected?
• What is the minimum age at which legal capacity, right to vote, age of criminal responsibility, marriageability and retirement age
should be set?
• In which periods of development do we have to expect which typical risks, crises or problems?
• What must be mediated or avoided in which age periods so that no lasting damage occurs?
• Developmental psychology focusses on...
• normative development + individual differences
▪ Which deviations from the norm are likely?
▪ How can they be explained?
▪ What do they mean for future life? Are they stable, are they changeable?
▪ How can future developments be influenced in a favorable way?
▪ How can people be immunized against harmful influences?
▪ How can we increase the probability of coping with adverse events?
The “When“in developmental psychology
What develops when?
▪ IMPORTANT: Biological age is never responsible for and thus does not explain changes.
▪ Changes can only be correlated with age – “vehicle” of change
▪ Goal = link changes to ‘’why“: which mechanisms drive development?
Time scale of development:
▪ Variability (= short-term changes that are more or less reversible) vs. change (= more or less enduring)
▪ Variability can predict change
The ‘’when’’ in developmental psychology
,In the first one we measure differences, in the second one changes
Research designs
Cross-sectional designs
▪ Studying groups of individuals of different ages at one point in time → Measure interindividual differences
Longitudinal designs
▪ Studying one group of individuals over a longer time period →Measure intraindividual change
▪ Cohort effect = Differences in developmentally relevant variables
that arise from (non-age-related) factors to which each birth
cohort is exposed →observed results caused by cohort
characteristics
▪ Cohort = any group that shares having experienced the same
cultural environment and historical events (e.g., same year of
birth)
The baby boom cohort, defined as people born from 1946 to
1964, is leaving an incredible imprint on the Western world as it
moves through society. The reason lies in size. When soldiers
returned from serving in World War II to get married, the average
family size ballooned. Families were traditional, Then, as rebellious
adolescents during the 1960s, the baby boomers helped engineer
a radical transformation in these attitudes and roles.
Changing conception of childhood
Colonial times: reaching adulthood at a much younger age, your chance of having any lifespan would have been far from secure.
Childhood mortality rates. Poverty, may have explained why child-rearing practices that we would view as abusive today used to be
routine. Separated from their parents during the first two years of life. Child abandonment was common. In addition, people did not
have our current sense that childhood is a special stage. In the seventeenth and eighteenth centuries, philosophers such as John
Locke and Jean Jacques Rousseau had a different vision of childhood. Locke: human beings are born a tabula rasa, the way we treat
children shapes their adult lives. Rousseau argued that babies enter life totally innocent; he felt we should shower these dependent
creatures with love. However, this message could fully penetrate society only when scientific advances improved living standards,
and we entered our modern age. At the beginning of the twentieth century, the developmentalist G. Stanley Hall identified a stage of
“storm and stress,” located between childhood and adulthood, which he named adolescence. However, it was only during the Great
Depression of the 1930s, when Roosevelt signed a bill making high school attendance mandatory, that adolescence became a
standard U.S. life stage. In recent decades, with so many of us going to college and, sometimes, graduate school, we have delayed
the beginning of adulthood to an older age. Developmentalists have identified a new in-between stage of life. Emerging adulthood,
lasting from age 18 to roughly the late twenties, is devoted to exploring our place in the world.
Changing conception of later life
For most of history the average life expectancy was shockingly low. Toward the end of the nineteenth century, life expectancy in the
United States rapidly improved. This twentieth-century life expectancy revolution is the most important milestone occurred in the
history of our species. The most dramatic increases in longevity occurred during the early decades of the last century, when medical
advances, such as antibiotics, wiped out deaths from many infectious diseases. The illnesses we now typically die from, called chronic
diseases, are tied to the aging process itself. A baby born in affluent parts of the world, especially if that child is female, has a good
chance of making it close to our maximum lifespan, the absolute biological limit of human life (about age 105). This extension of the
lifespan has changed how we think about every life stage.
We have moved the real beginning of old age beyond age 65. But as we approach our eighties, our chance of being disabled by
disease increases dramatically. Because of this, developmentalists make a distinction between two groups of older adults. The
young-old, defined as people in their sixties and seventies, often look and feel middle-aged. The old-old, people in their eighties and
beyond, seem in a different class changing conception of adult life
The impact of socioeconomic status
Socioeconomic status (SES) is a term referring to our education and our income. Not only do developmentalists rank people by
socioeconomic status, but they rank countries, too.
,Developed-world nations are characterized by their affluence, or high median per-person incomes
Developing-world countries are at the opposite end of the spectrum.
The impact of culture and Ethnicity
Residents of developing nations are less apt to have experienced the late-twentieth-century changes in men’s and women’s roles.
Divorce may be against the law. Arranged marriages still occur. Is there a way of categorizing cultures according to their basic values?
Developmentalists who study culture answer yes.
Collectivist cultures place a premium on social harmony. The family generations expect to live together, even as adults. Children are
taught to obey their elders, to suppress their feelings to value being respectful, and to subordinate their needs to the good of the
wider group.
Individualistic cultures emphasize independence, competition, and personal success. Children are encouraged to openly express
their emotions, to believe in their own personal power, to leave their parents, to stand on their own as self-sufficient and
independent adults. (Western nations)
Keep in mind that what unites us as people far out- weighs any minor distinctions based on culture, ethnicity, or race. Moreover,
making diversity generalizations is hazardous because of the diversity that exists within each nation and ethnic group. In the most
traditionally individualistic country people have a mix of collectivist and individualistic worldviews. As their standard of living rises,
residents of classic collectivistic countries, such as China, are developing much more individualistic, Western worldviews.
Can cohort effects be a problem for cross-sectional and longitudinal designs?
Cross-sectional designs
Advantages
▪ Economic in time (short duration between assessment and results)
▪ Rather cheep
▪ Shows similarities and differences between age groups
Disadvantages
▪ Age effects confounded with cohort effects
▪ No information on individual trajectories (interindividual differences instead of intraindividual change)
▪ Limited generalizability to other times of measurement
Longitudinally designs
Advantages
▪ True assessment of intraindividual change
▪ Assessment of stability and change of developmental characteristics
Disadvantages
▪ Age effects confounded with time-of-measurement effects / retest effects / attrition effects
▪ Limited generalizability to other cohorts
▪ Long duration
▪ High costs
Sequence models
Assessment methods
▪ Self-report vs. report by proxy (e.g., parent, spouse, caregiver)
▪ Interview
▪ Questionnaires
▪ Diaries
▪ Behavioral observation [naturalistic versus structured]
▪ Standardized Tests/Test batteries [comparison to norms]
▪ Experiments [Comparison of age groups or experimental conditions
with behavioral or neuro-biological data as outcome]
Research challenges
In developmental research, we focus on age groups (infants, children,
older adults) that may differ from younger adults in:
▪ Speech reception and production
▪ Sensomotoric abilities
▪ Suggestibility
▪ Attention span/Fatigue
▪ Subjective meaning of concepts
▪ Proportion of undiagnosed clinical impairment
Tip: Adjust methods to abilities of individual
▪ Age-adjusted task material (e.g., bigger font size)
▪ Oral responses instead of written
▪ Non-verbal task material
▪ Use of structured observation, physiological methods or report by
proxies as alternatives to verbal self-report
▪ Consider selectivity of sample→representative? (e.g., mobile older
adults with high cognitive functioning)
▪ Response bias: social desirability, accuracy-speed trade-off,
stereotypes
, Why and how do we develop?
Nature versus Nurture
Theories: lenses for looking at the lifespan
Theories offer insights into that crucial why
question. They attempt to explain what causes
us to act as we do. Theories in developmental
science may offer general explanations of
behavior that apply to people at every age. Or
they may focus on describing specific changes
that occur at particular ages.
Is it the environment, or the wider world, that
determines how we develop?
This is the famous nature (biology) versus
nurture (environment) question.
Nurture: Traditional behaviorism
Nature vs. Nurture: Prominent representatives
Can we introduce a phobia in an emotional stable child?
Charles Darwin (1809 – 1882) focus on innate
Behavior of children can be conditioned: Little Albert (1920)
biology VS. John B. Watson (1878 – 1958) focus
Nurture: Cognitive Behavioralism
Social-cognitive learning theory of Bandura (1970s) on learned behavior
▪ We are social species
▪ Humans learn trough modeling [Watching and imitating what others do]
▪ Modeling those who are nurturing, “cool” peers, the “experts”
Modeling similar people partly explains why, after children understand their gen- der label (girl or boy) at about age 2 1/2, they begin
to separate into sex-segregated play groups and prefer to play with their “own group. Another term used is Self-efficacy: our belief in
our competence, our sense that we can be successful at a given task. The goal we set predict which activities we engage in as we
travel through life. When self-efficacy is high, we not only take action but continue to act long after the traditional behavioral
approach suggests that extinction should occur. Many developmentalists find behaviorism unsatisfying. Notice that behaviorism
doesn’t address that vital question: What really motivates us as human beings? John Watson “love conditioning’’. (see attachment
theory after)
Nature-nurture: Critical/sensitive period
Critical period: a maturational period in which the nervous system is especially sensitive to certain environmental stimuli. If the
organism does not receive the appropriate stimulus at the right time, it is impossible, to develop certain associated functions later.
Nature-nurture: Critical periods during the life span
Are there critical periods to develop a skill?
Lorenz and his ‘children’: Imprinting. Incubator-hatched geese imprint on the first suitable moving stimulus they saw within "critical
period" between 13–16 hours after hatching
Nature-nurture: Critical/sensitive period
Sensitive period: a maturational period in which specific experiences have maximal positive or negative effects: Periods of increased
plasticity under the influence of specific condition factors.
Examples: binocular vision, language development, hearing – but also social development
▪ Explore the genetic contribution to differences between human beings
▪ Twin studies: Comparing traits (e.g., Agreeableness) in Identical (monozygotic) twins Share 100% of genes Fraternal (dizygotic)
twins Share 50% of genes
▪ Twin/adoption studies: identical twins separated in childhood
▪ If similar in Agreeableness --> evidence for role of genetics
behavioral genetics—a field devoted to studying the role genetics plays in understanding why people vary in their personalities or
any other human trait. To study the genetic contribution to human differences, behavioral geneticists use twin and adoption studies
as their main research tools. Behavioral genetic studies opened our eyes to the often incredible impact of nature. It’s tempting to
assume that children growing up in the same family share the same nurture, or environment. We inhabit very different life spaces
than our brothers and sisters. These environments are shaped in part by our genes.
The bottom line is that there is no such thing as nature or nurture. To really understand human development, we need to explore
how nature and nurture com- bine.
Heritability