Learning Objectives
By the end of this section, you will be able to:
- Describe the differences, similarities, and intersections between the fields of psychology, lifespan development, and human development
- Identify major questions of interest and topics of research within the field of lifespan development
- Differentiate between the various domains within the field of lifespan development
Hosea’s eighteen-year-old son, Landon, is about to graduate from high school. The family has taken several road trips to visit various colleges around the region, touring each campus and attending a football game with a particular interest in each school’s marching band, given Landon’s dedication to the trombone. So far, Landon has only expressed interest in two of the schools—both have more than 30,000 students, an exciting campus atmosphere, and large marching bands. Hosea knows his son, though. Landon is quite capable of accomplishing just about anything he sets his sights on, but often needs prodding and a bit of time to get started on a new goal. Hosea worries about the size of the two campus communities. Will Landon get lost among the crowd? Who will keep him on track? And then there’s the fact that Landon doesn’t know what he wants to study. Hosea also wonders how his own role as a father will change and what the right level of support to provide his son will be. What will he do for a new exercise hobby now that Landon, his best disc golf partner, is moving farther away? All these thoughts flood Hosea’s mind as he navigates the morning commute.
Hosea is grappling with various worries and uncertainties related to Landon’s impending graduation and transition to college. The study of lifespan development is focused on uncovering the psychological processes behind transitions like this. These processes help us to understand and explain an individual’s situation and concerns at a moment in time, as well as in all humans across the entire arc of the lifespan. As we seek to identify those connections and commonalities, we also find differences based on the wide variety of individual experiences, environmental conditions, and cultural backgrounds that make up the varied tapestry of human experience. We begin our journey into lifespan developmental psychology by defining the field, including its scope and relationship to other areas of science, outlining the major questions the discipline is concerned with studying, and previewing the components of an individual’s psychological development.
Lifespan Development as a Field of Study
In studying lifespan development, you’ll encounter several related scientific areas, often referred to as fields or disciplines, that are sometimes discussed nearly interchangeably. Let’s first situate lifespan psychology within the broader science of psychology, and then examine the meanings of the different terms for the field of study.
Psychology
The scientific study of the mind and all the behavior it produces is psychology. That is a short and simple definition, but it covers nearly the entire range of human experience. It recognizes that the mind plays a central role in human functioning and is the origin of all behavior and the center of all our responses to our environment.
Our mind, believed to be located within our brain, helps us to both shape and react to the world around us through our behavior. Behavior consists of physical, observable actions—things like riding a bike, cooking dinner, or texting a friend. Behavior is driven by affect and cognition, both of which are not always easily observable. Affect is a more precise term for emotional experience, which includes not only our own feelings and moods, but also the ability to discern or understand others’ emotional states. Cognition is the scientific term describing all of our thinking abilities, such as memory, computation, imagination, and language. If you can think it, feel it, or do it, psychologists study it.
In addition to its broad applicability in studying much of the human condition, psychology is notable for how it bridges previously separate areas of intellectual inquiry. Founded as a scientific discipline in 1879 by Wilhelm Wundt in Germany, psychology was meant to apply the scientific method to the big questions of human experience that philosophers had pondered for thousands of years. For example: “Are humans fundamentally good or bad?” “Do our early life experiences dictate our destiny?” “What is the nature of love?” “Do humans have free will?” and “What is consciousness?”
For nearly 150 years, psychological science has attempted to objectively answer these and thousands of other questions. Along the way, more than a dozen major subfields in psychology have emerged, including clinical, social, cognitive, industrial-organizational, health, and developmental psychology.
Lifespan Development and Human Development
The term lifespan development is another name for the subfield of developmental psychology. These terms describe the scientific study of growth, change, and stability in humans and the processes that underlie that growth and change—from conception until death, or colloquially, womb to tomb (Figure 1.2). Growth most often refers to maturation, which is typically biological and includes, for example, all the changes in height, weight, and physical characteristics that the transition to adolescence brings. Maturation refers to growth in psychological characteristics as well, like the expansion of vocabulary and social skills that occurs throughout childhood. Lastly, it is important to recognize that change is non-linear and can occur in both directions, whereas stability is characterized by an absence of pronounced change.
Developmental psychologists look for patterns of stability and investigate the biological, psychological, and other mechanisms that create stability in our behavior across time. Stability can be further defined as the state in which characteristics and abilities remain the same or function similarly across broad portions of the lifespan. For example, a young child who is shy in social situations may also show signs of social inhibition as a teenager and adult, even making a career choice that allows them to work behind the scenes instead of being the focus of attention. As you will learn, the concepts of temperament and personality help us understand why the way someone approaches the world often remains consistent across the lifespan.
Human development, closely related to lifespan development, is a perspective that incorporates a multidisciplinary approach to understanding the development process. In fact, some universities host academic departments separate from the psychology department that focus on human development. The main difference between the two is human development’s emphasis on the broad scope of factors that influence development. Specialists in human development often engage with theories, perspectives, and findings from other disciplines such as anthropology, medicine, communications, history, economics, medicine, and law.
The human development perspective helps remind us that human development is complex and is best understood using as many tools, perspectives, and levels of analysis as possible. The contemporary study of human growth, change, and stability across the lifespan has embraced this multidisciplinary perspective, whether it is called lifespan development or human development.
The History of Lifespan Development
Perhaps surprisingly, while lifespan development is a subfield of psychology, scientific and philosophical inquiry into the nature of human development (especially of children) pre-dates psychology’s establishment as a formal scientific discipline. The child study movement, which united disciplines such as education, social work and public policy to focus the scientific community’s interest in child development, arose during the Progressive Era of the 1890s, shortly after psychology’s founding (Siege & White, 1982).
However, one of the earliest published scientific accounts of child development had appeared nearly 100 years earlier. This was the work of French physician Jean-Marc Gaspard Itard, who conducted a case study of a boy who had spent his childhood without human contact. The case of Victor, the “Wild Boy of Aveyron” (Itard, 1802, 1821) continues to spark interest more than two centuries later. Through his work with Victor, Itard was able to begin exploring many of the fundamental questions that lifespan development concerns itself with today. So, we can trace the field of lifespan development to at least the start of the nineteenth century in Europe. Older roots lead back to ancient Greece, around 400 BCE. Socrates, Plato, Aristotle, and many other philosophers were fascinated with the same questions that contemporary developmental psychologists study. Today, we are fortunate to have a sophisticated set of science-based tools to help us uncover ever-more-precise answers.
As a scientific field of inquiry, lifespan development asks several fundamental questions, most of which are related to the passage of time. Exploring what changes we expect to see, when those changes occur during the lifespan, and how they come about is of central importance. Lifespan developmentalists are not content with simply describing and explaining human development across the lifespan, however. They want to make that knowledge applicable. Professionals from other fields—including medicine and health care, education, public policy, senior care, social work, the non-profit sector, and even toy design—are also keenly interested in taking theory and research findings from developmental science and using them in everyday life. This highlights the scientific goal of application—the process of translating evidence-based research and ideas into practical solutions to influence and improve human life. Developmental psychology, as a scientific discipline, advocates for public policies and interventions to be based on evidence derived from scientific research (Dahl et al., 2018). For example, once developmental science made clear that the reasoning abilities of teenagers, including risk assessment and reward-seeking behavior, are heavily swayed by peers (Steinberg, 2014), public policy agencies around the United States changed driving regulations to explicitly limit the number of non-familial teens who could be present in the car with a teenage driver (Figure 1.3).
It Depends
Does Money Really Buy Happiness?
Think about the age-old question of whether money can buy happiness (Diener et al. 1993; Diener et al., 2004). At first glance, it seems like it should. If you had enough money, you could purchase the necessities of life, and then some: a nicer home, better means of transportation, or more leisure time or activities. One approach to answering this question is to study the relationship between income and subjective well-being (a personal sense of satisfaction and happiness) in various countries across the globe. Data consistently show that subjective well-being rises with income (e.g., Stevenson & Wolfers, 2013).
At the same time, however, researchers found that above a certain level of income (roughly $90,000 USD per year) the relationship between income and subjective well-being leveled off (D’Ambrosio et al., 2020; Kahneman & Deaton, 2010). That is, a certain amount of money was necessary to satisfy wants and needs, but beyond that, earning more money began to have a diminishing influence.
A recent re-examination of the data looked more closely at this question by classifying participants by their reported level of emotional well-being: those scoring low on emotional well-being were placed in one group, those scoring in the middle in another, and so forth. When examined this way, the findings revealed three main conclusions. First, for those with low reported emotional well-being, there is indeed a steady increase in happiness with increasing income up to about $100,000 per year, and then a leveling off. Second, for those with a reported medium level of emotional well-being, the direct and proportional relationship between happiness and income continued across the entire income spectrum, meaning this group of individuals continued to get ever happier with increasing income. Finally, those individuals with high levels of emotional well-being showed an intensifying relationship between happiness and income after about $100,000 per year. In other words, happiness increased even more when earnings increased (Killingsworth et al., 2023).
Psychologists point out that money is not the only factor related to subjective well-being. Other factors such as self-esteem, strong relationships, social support, and a sense of freedom and optimism play a role (Choi et al., 2023). Throughout this course, you’ll explore many of the psychological factors and processes that promote life satisfaction.
Psychological Domains of the Developing Individual
When we think about the myriad sources of influence on an individual’s development, we immediately recognize how complex the task of understanding someone truly is. Likewise, the psychological makeup of a person is very complex. Emotional experiences, internal motivations and needs, temperament, personality, and a dozen or more major thinking-skill domains all have developmental pathways, even as they are shaped and influenced by one another. When we add biological growth and maturation, including the unfolding of each person’s unique genetic blueprint over time, answering the question, “Why is this person the way they are?” can be daunting.
Psychologists have devised a way to study developing individuals by looking at several major functional areas. These areas of development are biological, cognitive, social, emotional, and personality. This resource is organized along these functional lines by covering each period of the lifespan across two chapters: one chapter focused on biological/physical and cognitive developments, and another chapter focused on social and emotional developments, including the development of personality. Together, the two chapters for each life stage paint a complete picture of developmental psychology’s theories and findings. In many instances, a topic, like eating disorders, for example, may be covered in the physical and cognitive discussion, even though there are clear social, emotional, and personality aspects to the development of eating disorders. So, while this separation is useful for organizing our study of lifespan psychology, keep in mind that there are many intersections across areas (Figure 1.4). Note that developmental psychology sometimes refers to social, personality, and emotional topics as “psychosocial” development, to highlight the way these areas overlap with cognition and mental processes.
Link to Learning
Developed in 1985 by Deiner and colleagues, the Satisfaction With Life Scale (SWLS) measures an individual’s overall life satisfaction. Take this short assessment and follow the instructions for how to score and analyze your results.
References
Choi, Y., Joshanloo, M., Lee, J., Lee, H.-S., Lee, H.-P., & Song, J. (2023). Understanding key predictors of life satisfaction in a nationally representative sample of Koreans. International Journal of Environmental Research and Public Health, 20(18), Article 6745. https://doi.org/10.3390/ijerph20186745
Dahl, R. E., Allen, N. B., Wilbrecht, L., & Suleiman, A. B. (2018). Importance of investing in adolescence from a developmental science perspective. Nature, 554(7693), 441–450. https://doi.org/10.1038/nature25770
D'Ambrosio, C., Jäntti, M., & Lepinteur, R. (2020). Money and happiness: Income, wealth and subjective well-being. Social Indicators Research, 148(1), 47–66. https://doi.org/10.1007/s11205-019-02186-w
Diener, E., & Seligman, M. E. P. (2004). Beyond money: Toward an economy of well-being. Psychological Science in the Public Interest, 5(1), 1–31. https://doi.org/10.1111/j.0963-7214.2004.00501001.x
Diener, E., Sandvik, E., Seidlitz, L., & Diener, M. (1993). The relationship between income and subjective well-being: Relative or absolute? Social Indicators Research, 28(3), 195–223. https://doi.org/10.1007/BF01079018
Itard, J. M. G. (1802). An historical account of the discovery and education of a savage man, or of the first developments, physical and moral, of the young savage caught in the woods near Aveyron, in the year 1798. Richard Phillips.
Itard, J. M. G. (1821). Traité des maladies de l’oreille et de l’audition, Tome premier. Méquignon-Marvis.
Kahneman, D., & Deaton, A. (2010). High income improves evaluation of life but not emotional well-being. Proceedings of the National Academy of Sciences, 107(38), 16489–16493. https://doi.org/10.1073/pnas.1011492107
Killingsworth, M., Kahneman, D., & Mellers, B. (2023). Income and emotional well-being: a conflict resolved. Proceedings of the National Academy of Sciences, 120(10), 1–6. https://doi.org/10.1073/pnas.2208661120
Siege, A. & White, S. (1982). The child study movement: early growth and development of the symbolized child. Advances in Child Development and Behavior, 17, 233–285. https://doi.org/10.1016/S0065-2407(08)60361-4
Steinberg, L. (2014). Age of opportunity: Lessons from the new science of adolescence. Houghton Mifflin Harcourt.
Stevenson, B., & Wolfers, J. (2013). Subjective well-being and income: Is there any evidence of satiation? American Economic Review, 103(3), 598–604. https://doi.org/10.1257%2Faer.103.3.598