Describe the major theoretical perspectives of lifespan development
Connect each theoretical perspective with the themes of lifespan development
List the similarities and differences among the major theoretical perspectives
Provide examples of developmental concepts present in the lifespan
Shanae is in her late twenties and is several years into her career as a marketing consultant for a communications company. She finds life busy and fulfilling, and enjoys both the challenge of her job and the new city she lives in. However, she is concerned about her childhood friend, Georgia. Georgia visited Shanae last weekend and the two went out to several dance clubs to meet up with some of Shanae’s new friends. Amid all the fun, Georgia confided in Shanae that she wasn’t happy with her current job, didn’t know what career path she should pursue, and that her last relationship ended poorly. Sad and confused, Georgia seemed directionless and asked Shanae to give her advice. Shanae wants to help her friend but doesn’t know where to begin.
All human beings are complex. As individuals, we are collections of thousands of traits, capabilities, roles, relationships, and behavioral tendencies. Each of those characteristics grows, changes, or shows remarkable stability over the course of a lifetime. And the developmental trajectory of each characteristic is itself influenced by dozens or even hundreds of genes, experiences, and gene-environment interactions. In short, humans are multidimensional and impacted by a multitude of influences. Because of this complexity, lifespan development employs many theoretical perspectives and relies on research methodologies from multiple scientific disciplines. This multi-perspective, multidisciplinary approach aims to give us a full and accurate understanding of human functioning.
As you learn about some of the major theoretical perspectives or frameworks for understanding human behavior throughout the lifespan, there will be different perspectives to explain development and behavior. Instead of seeing these as contradicting each other, these varied perspectives can be considered together to enhance our understanding of how human behavior evolves over the lifespan. Even when two theories may seem diametrically opposed, there are often ways that they can be seen as complementary explanations of different areas of development.
Psychosocial Theory of Development
Erik
Erikson
(Figure 1.8) was born in Germany in the early twentieth century and became a teacher and psychoanalyst. He worked with psychoanalyst Anna
Freud
as each practiced and strove to further Sigmund Freud’s foundational theory of
psychosexual development
, which outlined a series of stages that children navigate in their personality development. When World War II approached, Erikson moved to the United States and spent time living with the Sioux in South Dakota. As a result of his training in psychoanalysis and his cultural experiences, he proposed a highly influential update to Sigmund Freud’s theory.
Erikson called this a
psychosocial theory of development
, which views human development as occurring in a discontinuous or stage-like fashion as we resolve increasingly complex and age-graded challenges posed by the social environment. The theory highlights the way the developing mind (the “psyche”) is embedded within society (the “social” part of the theory’s name), with an intricate back-and-forth between the changing demands and expectations of society and the mind’s responsive transformation.
Erikson’s theory was the first to consider the entire lifespan. The eight stages of life he outlined (Erikson, 1950, 1963) now form one of the organizing frameworks for the study of lifespan development. In Erikson’s view, as an individual enters each successive period of the lifespan, society presents a new challenge, called a
psychosocial crisis
, for the developing individual to work on (Table 1.1). For example, a toddler (aged one to three years) is learning to operate independently, which allows them physical independence from their caregivers. Successfully mastering this crisis results in the toddler having autonomy. Society, as represented by parents and other caregivers, has a vested interest in keeping the child safe during this early phase of life. Erikson called this struggle or tension between the child and society’s expectations the “autonomy versus shame/doubt” stage. The child spends eighteen to twenty-four months working to gain a basic sense of self-control while negotiating this achievement with their caregivers. In this way, Erikson proposed that personality development is an interactive process between an individual and society. Each stage affords the opportunity to achieve another level of psychosocial mastery, beginning with trust in our first year and culminating in a sense of integrity.
Stage
Age (years)
Developmental Task
Description
Successful Mastery
1
0–1
Trust versus Mistrust
Trust (or mistrust) that basic needs, such as nourishment and affection, will be met
Trust
2
1–3
Autonomy versus Shame/Doubt
Develop a sense of independence in many tasks
Autonomy
3
3–6
Initiative versus Guilt
Take initiative on some activities—may develop guilt when unsuccessful or boundaries overstepped
Initiative
4
7–11
Industry versus Inferiority
Develop self-confidence in abilities when competent or sense of inferiority when not
Industry
5
12–18
Identity versus Confusion
Experiment with and develop identity and roles
Identity
6
19–29
Intimacy versus Isolation
Establish intimacy and relationships with others
Intimacy
7
30–64
Generativity versus Stagnation
Contribute to society and be part of a family
Generativity
8
65+
Integrity versus Despair
Assess and make sense of life and meaning of contributions
Integrity
Table 1.1
Erikson’s Psychosocial Stages of Development
(source: Erikson, 1950, 1963)
Cognitive Perspectives
The
cognitive perspective
in developmental psychology emphasizes the study of mental processes and how they change over time. Key figures in this area include Jean Piaget, known for the stage theory of cognitive development; Lev Vygotsky, who emphasized the role of social interaction in cognitive development; and information processing theorists who examine how the mind processes information like a computer.
Stage Theory of Cognitive Development
Swiss biologist Jean
Piaget
is famous for contributing theories regarding changes in cognitive ability that occur as we move from infancy to adulthood. He spent his early years as a scientist studying various animals. He then worked on creating some of the earliest measures of intelligence. As he was writing test items, he interviewed children and asked them to explain the thought process behind their answers to sample questions. One of Piaget’s early insights was to focus on the children’s incorrect answers because they provided a window into their reasoning abilities. From these observations, he developed his prominent
stage theory of cognitive development
(Piaget, 1952, 1954). Piaget’s theory, like Erikson’s, is an organizing framework for the modern study of lifespan development.
Piaget’s theory views development as occurring through a series of age-based stages (Table 1.2). As we age and our brain and bodily systems mature, we are afforded new ways of interacting with the world. The combination of these new physical and sensory capabilities with the new experiences the environment offers drives the development of thinking abilities that are acquired across the first twenty years or so of life. Along the way, individuals are active participants in their own development, testing out ideas and capabilities in the world and formulating a coherent sense of how the world works. Piaget’s emphasis on the active nature of learning and development, his focus on the reasoning behind wrong answers, and his delineation of the psychological processes occurring in cognitive development made for a groundbreaking theory.
Age (years)
Stage
Description
Developmental Issues
0–2
Sensorimotor
World experienced through senses and actions
Object permanence
Stranger anxiety
2–6
Preoperational
Use words and images to represent things, but lack logical reasoning
Pretend play
Egocentrism
Language development
7–11
Concrete operational
Understand concrete events and analogies logically; perform arithmetical operations
Conservations
Mathematical transformations
12+
Formal operational
Formal operations
Utilize abstract reasoning
Abstract logic
Moral reasoning
Table 1.2
Piaget’s Stages of Cognitive Development
(source: Piaget, 1952, 1954)
Sociocultural Theory of Cognitive Development
Russian psychologist Lev
Vygotsky
explored learning and cognitive development in children during the early twentieth century, and demonstrated how important social interaction is for learning and growing. He died in his thirties and his work did not become widely known outside Russia until the 1970s, when his theory became very influential in the field of developmental psychology.
Vygotsky (1978, 1998) proposed a
sociocultural theory of cognitive development
, emphasizing that thinking abilities are embedded within an individual’s social and cultural context. Whereas Piaget’s theory focused on a person’s step-like journey of coming to understand the world, Vygotsky saw cognitive development as supported and propelled by social tools available to the individual learner. These social tools include language, direct support from others, and technological aids. Vygotsky, then, was among the first to recognize that
language
guides cognition and gives shape to ideas that can be readily communicated with others through words. One such example is
private speech
, whereby the learner may use words to audibly (or not) keep themselves on track during a difficult problem-solving session. If you’ve ever rehearsed a list of grocery items out loud while you searched for a place to record them, you’ve used language in such a way. Acronyms for remembering complex math concepts, such as PEMDAS (parentheses, exponents, multiplication, division, addition, and subtraction) for the order of arithmetic operations, are another example of language use supporting cognition.
Link to Learning
Being caught talking to yourself can feel embarrassing, but it is normal to do so. Most people talk to themselves throughout a typical day. View this
TED talk about the psychological benefits of positive self-talk
to learn more about why we do this and the impact of what we say to ourselves.
The application of various forms of technology, another social tool, can allow an individual to perform complex tasks more easily than by relying on brain power alone. From this perspective, using a calculator to do basic calculations frees up the mind to think about the more important and complex parts of a word problem, for example. Word processing programs and apps that autocorrect spelling and grammar support thinking by allowing the writer to focus on the ideas of their message, instead of on the mechanics of writing.
Vygotsky is best known for championing social supports in propelling cognitive development and educational achievement. His notion of the
zone of proximal development (ZPD)
states that all of us are capable of thinking and achieving at a higher level than we may realize: there are concepts and ideas just beyond our current abilities that we are ready to master if only we have a little help, often from others. Educators and parents have used the idea of
scaffolding
to help learners achieve beyond their current level, gradually withdrawing support as the student becomes more competent. Learning how to ride a bicycle is a great example of scaffolding. Support for learning this difficult task can come through training wheels, or from a caregiver holding the bicycle seat while running alongside the child. As the child gains a sense of balance and masters the mechanics of pedaling and steering, the training wheels become less necessary and are eventually removed, and the caregiver lets go of the seat. The child has reached a new level of development with guided and temporary support.
Information Processing Theory
Our digital age has also brought new ways of thinking about how the human
brain
works. Although the computer was conceptualized via ideas about how the human brain functions, psychologists now use the functioning of a computer as a metaphor for understanding how we think.
From the 1960s onward, the metaphor of
information processing
has been a helpful way to think about cognition and cognitive development (Atkinson & Schriffrin, 1968). One key concept is that of information flowing into the brain, being processed or acted on, and then leaving the brain in the form of behavioral output, just like data in a computer. This concept also relies on a modular view of the brain: the idea that discrete structures within our brain specialize in various cognitive tasks, such as memory, sensory processing, language comprehension, and spatial reasoning. As information flows into the brain through various senses, it is routed to the appropriate brain region and acted on, and then behaviors emerge through actions and words. From a developmental perspective, cognitive development is fostered as the various parts of this information processing system mature and gain operational efficiency.
While the information processing model is useful, it has also become more simplistic as science has progressed. Our brain indeed has many functional modules that are connected and share information back and forth. The advent of brain imaging technology brought insight into further complexities of how the brain and its cognitive abilities are organized.
Cognitive Neuroscience
Advancement in computing technology ushered in increasingly sophisticated ways to image, or view, the brain. At first, technologies such as x-rays and CT-scans (computed tomography scan) were used to make images of brain structures. Often, researchers would correlate brain injury and loss of functionality with changes seen in these images. The invention of MRI (magnetic resonance imaging) scanning made highly detailed imaging possible. Finally, an innovative software development allowed many such images to be made quickly and spliced together into a real-time video of the brain at work. This technique is called fMRI (or functional magnetic resonance imaging.)
Together, these are imaging tools that psychologists working in
cognitive neuroscience
use to connect brain structure and function with behavior. Scientists can now see which areas of the brain become more active when participants solve math problems, think about a romantic partner, or perform a memory recall task, among many other fascinating findings (Figure 1.9). Periodic brain scans allow researchers to observe the effects of learning and mastering a challenging task over time, and to look for changes in connectivity among various brain regions as individual’s age. The Dallas Lifespan Brain Study (DLBS) is an example of the advances made by using these technologies to think about the aging brain. For example, contrary to the expectation that brain changes and symptoms of Alzheimer’s disease and other forms of dementia begin in late adulthood, research from DLBS has shown a steady relation between changes in the brain and a decline in cognitive function beginning much earlier in adulthood (Smith et al., 2023). This provides hope for advancements in the identification, prevention, and treatment of these diseases.
Biological and Evolutionary Perspectives
It can be difficult to distinguish between fields that study the interaction of genes and the environment, such as the fields of evolutionary psychology and behavioral genetics. In both fields, it is understood that genes not only code for particular traits, but also contribute to certain patterns of cognition and behavior. Evolutionary psychology focuses on how universal patterns of behavior and cognitive processes have evolved over time, whereas behavioral geneticists study how individual differences arise, in the present, through the interaction of genes and the environment. When studying human behavior, behavioral geneticists often employ twin and adoption studies to research to help provide insight into the relative importance of genes and environment for the expression of a given trait.
Many of the most influential early psychologists and developmental theorists were medical practitioners or had some form of training in biology. It is no surprise, then, that various biological principles and methodologies have come to play a prominent role in thinking about human development, including evolutionary factors, behavioral genetics, and ethology.
Ethology
The study of animal behavior is called
ethology
. Developmental psychologists who use this approach study animals, especially other mammals, as models to discover and test ideas relevant to understanding human functioning. In 1930s England, John
Bowlby
used his medical and psychoanalytic training to research the experience of children growing up in orphanages and similar institutions. Even though these children had all the physical necessities for health—clothing, shelter, and food—he was concerned by the emotional and social effects he observed. Using these observations and his findings from animal studies, including rodents and monkeys, Bowlby formed the theory of
attachment
, an enduring, emotionally significant bond that forms between two individuals, often in a caregiving context (Bowlby, 1951). The development of at least one attachment, the basis of human bonding, is essential to human development. Bowlby’s discovery of this necessary component for human flourishing opened a new area of developmental inquiry with far-ranging consequences for individuals across the entire lifespan.
It Depends: How Does Attachment in Childhood Carry across the Lifespan?
You’ve likely heard that what happens in childhood has lifelong consequences. In many ways, the field of lifespan development can be proud of the pervasiveness of this idea in that it can help to focus attention, priority, and care on child development. Of course, this idea does not mean that childhood experiences define our destiny or that experiences later in life do not matter as much in comparison.
Attachment is the enduring bond that develops between child and caregiver. The quality of this bond depends on the pattern of interactions between these individuals. How sensitive has the caregiver been to the child’s physical and psychological needs? How responsive has the caregiver been in addressing those needs? And finally, how consistently has there been a match between this sensitivity and responsiveness? When there is a history of consistent, sensitive, and responsive caregiving, a secure attachment develops. If one or more of those dynamics is missing, various forms of insecure attachment may develop. The functional purpose of this enduring attachment bond is not just the emotional and physical support that comes with being nurtured, but also a sense of security that allows the child to venture forth into the world and explore. This exploration supports other aspects of human development including cognitive, social, and personality domains.
The quality of the early attachment bond carries forward to future significant relationships. A child’s expectations of what a relationship is, what it is for, and how others will behave toward them are informed by that first attachment bond. The impact of stability of attachment across the lifespan has been well-documented. For example, attachment quality predicts how far of a distance a young adult is comfortable traveling to attend college (secure attachment predicts the ability to move farther away from home), as well as academic success once at college, with a more secure attachment history predicting better academic success (Kurland et al., 2020). Attachment quality also has connections to later life stages, such as when the now-adult child becomes the caregiver for an elderly parent. A secure attachment history is related to an increased desire to care for the elderly and the amount and quality of caregiving provided (Karantzas et al., 2019).
Despite these findings suggesting remarkable stability across the lifespan, a central feature of attachment theory is the ability for an insecurely attached individual to re-approach attachment quality by forming a significant relationship with a securely attached person at any time in life. That is, a person with a secure attachment history can provide a model for an insecurely attached person to emulate, thereby changing that person from that point forward (Ainsworth et al., 1979; Hazan & Shaver, 1987).
So, do childhood experiences lead to lifelong consequences? Indeed they do, but humans have a remarkable capacity for change, growth, re-learning, and development, as shown through the example of attachment theory.
Evolutionary Psychology
The approach of
evolutionary psychology
looks to the theory of
natural selection
to explain the emergence, development, and persistence of various psychological characteristics in humans. Natural selection posits that long-ago environmental conditions favored those with certain physical and psychological characteristics making them more likely to survive and be able to reproduce. These individuals could then pass on their genes, coded for those characteristics, to their offspring. Across many generations, the characteristics that conferred such a survival advantage became part of the species’ genetic package. Examples of human functioning that have been studied from an evolutionary perspective include aggression and prosocial (helping) behavior, mating preferences, attachment, wisdom, the timing of puberty, and sleep patterns, among many others.
Behavioral Genetics
The field of inquiry that most directly explores the intersection between
nature and nurture
is called
behavioral genetics
. Research in this area helps to explain how much variation in a psychological characteristic is due to genetic differences among individuals, which will shape the kinds of interventions and other applications science can offer.
To measure the
heritability estimate
for a given psychological characteristic, researchers frequently use a
kinship study
, which examines how genetic and environmental similarities between individuals relate to differences in their traits or behaviors. In
twin studies
, a type of kinship study, the correspondence between the genetic relatedness of twins specifically (both identical and fraternal) and resulting psychological characteristics are examined (Figure 1.10).
Kinship studies allow psychologists to take advantage of naturally occurring variations in the genetic similarities among individuals and compare that information with what we know about the degree of similarity or dissimilarity in the same individuals’ environments. For example, we know that identical twins who grow up together share close to 100 percent of their genes but also have a high degree of overlap in their upbringing. Fraternal twins, like any non-identical set of siblings, share approximately 50 percent of their genes, and have considerably more environmental overlap than non-twin typical siblings who may be born years apart and grow up in different stages or versions of the same household. Studies that observe family members in these contexts allow scientists to discern the relative contributions of genes and environment to the development of psychological characteristics.
Behaviorist Perspectives
For much of psychology’s early history as a scientific discipline, the
behaviorist perspective
dominated thinking about how an individual’s characteristics develop and change over time. This perspective, also known as
learning theory
, focuses on an environment’s role in influencing behavior and behavioral change. When we think of
language
development, for instance, it is easy to be amazed by the rapid rate of growth in a child’s vocabulary size, complexity of sentences, and skill in communication. It may seem that language development happens suddenly and naturally. Upon further examination, however, and with using the learning theories that make up the behaviorist perspective, we can see a tremendous amount of environmental influence working to build and shape the child’s acquisition of language. Foundational research into these areas includes the development of theories about classical conditioning, operant conditioning, and observational learning.
Classical Conditioning
Early in psychology’s history as a science, Russian physiologist Ivan
Pavlov
accidentally uncovered the principles that came to be known as
classical conditioning
. While studying the digestive system of dogs, Pavlov noticed that his experimental subjects, dogs, would often salivate even when he hadn’t produced the meat powder that was meant to trigger their salivation. The dogs had come to associate the sound of a bell, which signaled the start of each experimental trial, with impending food, and thus they would salivate when they heard the bell, even without the meat powder. Pavlov became curious about this and soon discovered the principles of classical conditioning.
In classical conditioning, a neutral or meaningless stimulus, in the case of Pavlov’s dogs the sound of the bell, takes on the same meaning for the learner as the natural stimulus with which it is accidentally or intentionally paired, in this case the meat powder. As a result, the previously neutral stimulus then produces the same behavioral outcome as the natural stimulus. The natural stimulus, which has inherent meaning like the smell of food, is called an
unconditioned stimulus
, while the once-neutral trigger is called a
conditioned stimulus
because the learner has become conditioned to respond to it (Figure 1.11).
This type of learning is a form of
associative learning
, in which the repeated presentation of two stimuli results in linking them, making their meanings synonymous. A language learner’s vocabulary can be built this way (Smith & Yu, 2008). For example, a toddler is presented with an apple and at the same time hears the word “apple.” It doesn’t take many repetitions before the child associates the object apple with the word label “apple.”
Operant Conditioning
B.F.
Skinner
uncovered fundamental principles of learning theory in the early twentieth century (Skinner, 1938, 1961). Skinner’s studies built on Thorndike's
law of effect
—the philosophical idea that the consequences of an action tend to alter the frequency of the action (Thorndike, 1911). From this came the understanding of
operant conditioning
, the theory of learning that outlines how feedback from the environment shapes an individual’s behavior. Essentially, Skinner’s theory explains how behaviors are strengthened or weakened according to their consequences.
According to Skinner’s operant conditioning theory, learning starts with an individual performing a behavior. The environment can then provide encouraging feedback called
reinforcement
, discouraging feedback in the form of
punishment
, or a neutral response, including ignoring the behavior. Given positive or negative feedback, the individual learns the value of the behavior and typically modifies its frequency. The practice of
shaping
gradually builds complex behaviors by rewarding actions that get closer and closer to the desired outcome.
For example, in the case of language development, when a caregiver holds up an apple and a toddler says “appah,” the caregiver may exclaim excitedly, “Yes! An apple!” The next week, though, the caregiver might respond with less enthusiasm and instead repeat, “Apple . . . aaa-pulll.” Only when the child responds with the more accurate “ahpul” would the caregiver give the same enthusiastic praise as before. In this way, speech can be built and shaped over time. Notice the role of rich and varied environmental feedback in producing this type of learning.
Albert
Bandura
studied the principles of
observational learning
that explain how learning can occur through the social act of observing others who are themselves learning (Bandura, 1961). Among Bandura’s contributions are two noteworthy insights to our understanding of human development and learning. First, his work recognized that humans are social animals: we live, learn, and develop within the presence of others, and we are influenced by and influence one another. Second, he demonstrated that the processes of classical conditioning and operant conditioning can guide learning: when we observe others’ actions and the consequences of those actions, we learn too. This indirect or vicarious learning through others is common in today’s media-saturated environment, where we are exposed to the actions and learning of others through our computer screens, smartphones, and televisions (Figure 1.12). Long-running educational television shows like
Sesame Street
and
Dora the Explorer
provide abundant opportunities for a child viewer to learn language, for instance, by observing others’ language learning.
The theories and principles that together make up the behaviorist perspective offer a powerful set of explanations for the development of complex behaviors, capabilities, and characteristics, such as language and personality, especially in response to environmental feedback.
Intersections and Contexts: Developmental Assets Approach
In thinking about lifespan development, what specific developmental outcomes should we seek to foster in the developing individual? The theories of Piaget, and Erikson, for example, identify the highest levels of development in cognition and personality as desirable achievements along life’s journey, especially by the time adulthood is reached. A group of developmental psychologists at the Search Institute have surveyed the large body of developmental findings and outlined forty qualities that should be nurtured during youth. These qualities are called developmental assets.
Twenty of these developmental assets are internal to the person, such as psychological qualities like self-esteem and a sense of purpose. The other twenty assets are external—resources like a caring educational environment and positive family communication—that are found in particular social connections and the broader community. A sample listing of these assets is found in Table 1.3.
Type of Asset
Asset Category
Description
External
Support
Strong support and effective communication from family, school, and other adults in the community
External
Empowerment
Adults in the community value youth engagement and strive to provide safe environments
External
Boundaries and expectations
Clear and consistent structures in family, school, and community that encourage youth toward high expectations and model positive, responsible behavior
External
Constructive use of time
Participation in a balance of activities such as youth and community programs, creative arts, sports, and religious practices
Internal
Commitment to learning
Motivation to be engaged in learning, fulfill academic responsibilities, and do their best in schooling
Internal
Positive values
Practicing behaviors based on caring, equality, integrity, honesty, and responsibility
Internal
Social competencies
Development of social skills and personal abilities aimed toward healthy choices, tolerance, understanding, and positive relationships with others
Internal
Positive identity
Sense of positive self-esteem, empowerment, and optimistic outlook over one’s future
Table 1.3
Developmental Assets Framework
The Developmental Assets Framework is copyrighted by Search Institute, Minneapolis, MN (www.searchinstitute.org) and used with permission.
These assets provide an inventory of developmental goals whose achievement can be assessed at various points in life. But they also serve as a set of value statements for those concerned with developing healthy and well-functioning individuals in our society. Research validating the assets has shown the benefits of this inventory approach. A large-scale survey of more than 100,000 youth in the United States revealed that individuals in grades six through twelve possessed, on average, twenty of the assets (Pekel et al., 2015; Roehlkepartain, 2015). The most common, held by more than 70 percent of the survey respondents, were integrity, achievement motivation, family support, positive peer influence, and a favorable view of their future. The least common, attained by 25 percent or fewer, were living in a community that values youth, reading for pleasure, and having creative activities to pursue.
Developing and possessing these assets makes a difference. The more assets an individual has acquired, the more likely they are to succeed in school, help others, value diversity, resist danger, and overcome adversity. In short, the more assets one possesses, the more likely the individual is to thrive. Individuals with fewer assets are more likely to engage in risky behaviors including drug and alcohol misuse and school truancy. Surveys like this allow us to measure our performance as a community in supporting the development of healthy and well-adjusted individuals.
References
Ainsworth, M. D. S., Blehar, M. C., Waters, E., & Wall, S. (1979).
Patterns of Attachment
. Psychology Press.
Atkinson, R. C. (1968). Human memory: A proposed system and its control processes.
The psychology of learning and motivation, 2
.
Bandura, A., Ross, D., & Ross, S. A. (1961). Transmission of aggression through imitation of aggressive models.
Journal of Abnormal and Social Psychology, 63
, 575–582. doi.org/10.1037/h0045925
Bowlby, J. (1951). Maternal care and mental health.
Bulletin of the World Health Organization, 3
, 355-534.
Erikson, E. H. (1950).
Childhood and society
. W. W. Norton & Co.
Erikson, E. H. (1963).
Childhood and society
(2nd ed.). W. W. Norton & Co.
Ginsburg, H. P., & Opper, S. (1988).
Piaget's theory of intellectual development
(3rd ed.). Prentice-Hall, Inc.
Hazan, C., & Shaver, P. (1987). Romantic love conceptualized as an attachment process.
Journal of Personality and Social Psychology, 52
(3), 511–524. doi.org/10.1037/0022-3514.52.3.511
Karantzas, G., Romano, D., & Lee, J. (2019). Attachment and aged care: A systematic review of current research.
Current Opinion in Psychology, 25
, 37–46.
https://doi.org/10.1016/j.copsyc.2018.02.016
Kurland, R. & Siegel, H. (2020). Attachment and college academic success: A four-year longitudinal study.
Open Journal of Social Sciences, 8,
45–55.
https://doi.org/10.4236/jss.2020.812005
Piaget, J. (1952).
The origins of intelligence in children
. New York: International University Press. doi.org/10.1037/11494-000
Piaget, J. (1954).
The construction of reality in the child
. New York: Basic Books. dx.doi.org/10.1037/11168-000
Smith, E. T., Hennessee, J. P., Wig, G. S., Frank, S., Gonzalez, H., Bacci, J., Chan, M., Carreno, C. A., Kennedy, K. M., Rodrigue, K. M., Hertzog, C., Park, D. C. (2023). Longitudinal changes in gray matter correspond to changes in cognition across the lifespan: Implications for theories of cognition.
Neurobiology of Aging, 129
, 1–14.
https://doi.org/10.1016/j.neurobiolaging.2023.04.014
Pekel, K.., Roehlkepartain, E. C., Syvertsen, A. K., & Scales, P. C. (2015).
Don’t forget the families: The missing piece in America’s efforts to help all children succeed (summary of key findings)
. Search Institute.
https://pub.search-institute.org/fil...10-13-2015.pdf
Roehlkepartain, E. C. (2015). Years of Developmental Assets: Personal reflections (and a little data).
Search Institute
, 1-6.
Skinner, B. F. (1938).
The behavior of organisms: An experimental analysis
. Appleton-Century-Crofts.
Skinner, B. F. (1961).
Cumulative record: A selection of papers
. Appleton-Century-Crofts.
Smith, E. T., Hennessee, J. P., Wig, G. S., Frank, S., Gonzalez, H., Bacci, J., Chan, M., Carreno, C. A., Kennedy, K. M., Rodrigue, K. M., Hertzog, C., & Park, D. C. (2023). Longitudinal changes in gray matter correspond to changes in cognition across the lifespan: implications for theories of cognition.
Neurobiology of aging, 129
, 1–14.
https://doi.org/10.1016/j.neurobiolaging.2023.04.014
Smith, L., & Yu, C. (2008). Infants rapidly learn word-referent mappings via cross-situational statistics.
Cognition, 106
(3), 1558-1568.
intelligence: An experimental study of the associative processes in animals.
Psychological Monographs, 8
.
Vygotsky, L. (1978).
Mind in society: The development of higher psychological processes
(M. Cole, V. John-Steiner, S. Scribner, & E. Souberman, Eds. & Trans.). Harvard University Press.
Vygotsky, L.S. (1998). Translated by Rieber, R. W., “The Collected Works of L.S. Vygotsky,”
Volume 5, Child Psychology
. Plenum Press.