1.1: Principles of Development

The terms "growth" and "development" are often used interchangeably. Developmental psychology is the science of human and [other] animal behavior and mental processes as seen through the lens of the passage of time. As the individual organism ages, the behavior and mental processes that we are interested in as psychologists, also change.

There are several underlying principles of development to keep in mind: Development is --

Lifelong

Development is lifelong and change is apparent across the lifespan (although this text deals only with changes up to adolescence). And early experiences affect later development. For example, Tamashiro, Terrillon, Hyun, Koenig and Moran (2009) found that prenatal high fat diet or stress increases adult rat obesity and insulin resistance. Talk about a long term effect!

Multidirectional

Often when I use words like "grow" or "develop" I think of an increase in whatever realm I am talking about. However it is important to keep in mind that development is multidirectional. We show gains in some areas of development, while showing loss in other areas. Certainly, you could say that for something like self esteem, as an individual grows, our self esteem develops into more and more facets. A child may only think of themself as "good" or "bad," whereas an adolescent is more likely to say that they are not a great sibling, but a wonderful friend, and not that good at math but pretty good at social studies.

On the other hand, as we age, not everything increases. For instance, infants are born with certain innate reflexes like the stepping reflex. As they become more coordinated and pulling oneself up and standing and walking emerges as a child grows, those innate reflexes disappear (Story, 2018). Another example is that infants are born with more bones (about 270) than they end up with as adults (about 206)(Cowan and Kahai, 2022). For example, the skull is actually in five pieces at birth, to allow for some malleability as it moves down the vaginal canal during labor. These sutures fuse over during infancy into one skull covering the brain.

Figure \(\PageIndex{1}\): Generally infants are born with five bones in their skull with sutures that fuse over making one skull by the end of infancy -- one of the things that leads to adults having fewer bones than newborns do. OpenStax College, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons

Generally infants are born with five bones in their skull with sutures that fuse over making one skull by the end of infancy -- one of the things that leads to adults having fewer bones than newborns do. OpenStax College, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons

Multidimensional

Development is multidimensional. We change across three general domains/dimensions: biological, cognitive, and socio-emotional, as we progress through life.

Biological

The biological domain refers to changes in body size, parts, and functions. As psychologists we are particularly interested in changes in brain development and neurological function. As Arduini points out, we are certainly familiar with the height and weight charts at pediatricians’ offices, but it is the brain development that underlies the development of gross and fine motor skills and the coordination between emotion and planning (or lack thereof) in adolescence. Of course, there are also changes in health, resilience and susceptibility. The importance of nutrition and exercise cannot be understated (Arduini, 2022).

Cognitive

The cognitive domain refers to changes in thinking, problem solving, memory, attention, language and intelligence. All of these change with age as well as with experience, which of course varies widely even in the same city or geographical areas of the world. Most people are aware that brain development affects thinking, memory and problem solving, but they may not necessarily be fully aware of how circumstances can change the trajectory of this development in multiple ways.

Social/Emotional

The social and emotional domain (also referred to as psychosocial) refers to changes in emotions, self regulation, interpersonal relationships beginning with attachment to caregivers, identity development, self esteem and play. In the beginning, it is only one’s close family or caregivers that comprise an infant’s immediate social realm (of course larger social influences permeate). However, children’s immediate social relationships bloom quickly as they enter school, engage with neighbors, friends, religious realms, parks and so on.

Of course, these domains do not develop independently but rather influence each other in multiple interconnected ways. For example, researchers historically viewed the development of moral decision making as a cognitive function. Now it is becoming increasingly clearer that emotions play an important role in moral decisions, and neuroscience has devoted research to examining which areas of the brain might be implicated in such decision making.

Characterized by Plasticity

Development is characterized by plasticity, which is our ability to change and that many of our characteristics are malleable. Young children’s brains are particularly changeable (though there is more and more research showing that even older adults; brains remain plastic). While this might appear to be a disadvantage in terms of how easily children’s brains can be affected, in fact it is pretty marvelous how this plasticity lends to resilience. For example, Mathern (2010) suggests that when children go through a hemispherectomy (an entire half of the brain is surgically removed) because of seizures, their cognitive abilities improve to the point where many eventually go to college or vocational school.

Multicontextual

Development is multicontextual.[1] Not only do our parents pass down their genes to us, but for the most part they also provide the family and home context within which we develop, and that home is located within a larger community – tribe, village or city – with different climate conditions, economic underpinnings, cultural values and political influences.

In Baltes’ theory, the paradigm of contextualism refers to the idea that three systems of biological and environmental influences work together to influence development. Development occurs in context and varies from person to person, depending on factors such as a person’s biology, family, school, church, profession, nationality, and ethnicity. Baltes identified three types of influences that operate throughout the life course: normative age-graded influences, normative history-graded influences, and non-normative influences. Baltes wrote that these three influences operate throughout the life course, their effects accumulate with time, and, as a dynamic package, they are responsible for how lives develop.

Normative age-graded influences

Normative age-graded influences are those biological and environmental factors that have a strong correlation with chronological age, such as puberty or menopause, or age-based social practices such as beginning school or entering retirement.

Normative history-graded influences

Normative history-graded influences are associated with a specific time period that defines the broader environmental and cultural context in which an individual develops. For example, development and identity are influenced by historical events of the people who experience them, such as the Great Depression, WWII, Vietnam, the Cold War, the War on Terror, or advances in technology.

This has been exemplified in numerous studies, including Nesselroade and Baltes’, showing that the level and direction of change in adolescent personality development was influenced as strongly by the socio-cultural settings at the time of the Vietnam war as age-related factors. The study involved individuals of four different adolescent age groups whom all showed significant personality development in the same direction (a tendency to occupy themselves with ethical, moral, and political issues rather than cognitive achievement). Similarly, Elder showed that the Great Depression was a setting that significantly affected the development of adolescents and their corresponding adult personalities by showing a similar common personality development across age groups. Baltes’ theory also states that the historical socio-cultural setting had an effect on the development of an individual’s intelligence. The areas of influence that Baltes thought most important to the development of intelligence were health, education, and work. The first two areas, health and education, significantly affect adolescent development because healthy children who are educated effectively will tend to develop a higher level of intelligence. The environmental factors, health and education, have been suggested by Neiss and Rowe to have as much effect on intelligence as inherited intelligence.

Non-normative influences

Non-normative influences are unpredictable and not tied to a certain time in a person’s development or to a historical period. They are the unique experiences of an individual, whether biological or environmental, that shape the development process. These could include milestones like earning a master’s degree or getting a certain job offer or other events like going through a divorce or coping with the death of a child.

The most important aspect of contextualism as a paradigm is that the three systems of influence - age-graded, history-graded and non-normative - work together to affect development. Taking adolescent development as an example, the age-graded influences would help to explain the similarities within a cohort, the history- graded influences would help to explain the differences between cohorts, and the non-normative influences would explain the idiosyncrasies of each adolescent’s individual development. When all influences are considered together, it provides a broader explanation of an adolescent’s development.

Other Contextual Influences on Development

What is meant by the word “context”? It means that we are influenced by when and where we live. Our actions, beliefs, and values are a response to the circumstances surrounding us. Sternberg describes contextual intelligence as the ability to understand what is called for in a situation (Sternberg, 1996). The key here is to understand that behaviors, motivations, emotions, and choices are all part of a bigger picture. Our concerns are such because of who we are socially, where we live, and when we live; they are part of a social climate and set of realities that surround us. Important social factors include cohort, social class, gender, race, ethnicity, and age. Let’s begin by exploring two of these: cohort and social class.

Cohort

(See history-graded influences above.) A cohort is a group of people who are born at roughly the same time period in a particular society. Cohorts share histories and contexts for living. Members of a cohort have experienced the same historical events and cultural climates which have an impact on the values, priorities, and goals that may guide their lives. Consider the differences in experiences of someone from the ‘Silent’ generation that lived with constant scarcity and rationing during WWII versus the economic prosperity that followed for the ‘Baby Boomer’ generation and how those historical contexts influence their development.

Socioeconomic status (SES)

Another context that affects our lives is our social standing, socioeconomic status, or social class. Socioeconomic status 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. We also find differences between social classes in these and other areas of development. Often, those in low socioeconomic groups, people living in poverty, are disadvantaged, lack of opportunities, and have different life experiences than those with more financial stability and wealth.

Poverty describes the state of not having access to material resources, wealth, or income, and also includes the lack of opportunity to improve one’s standard of living and acquire resources. Life chances is a term used to describe someone’s access to marketplace resources—essentially, how likely it is in their environment that they might be able to find employment or have a social safety net. Someone who is living in poverty but has high life chances may be able to improve their economic standing, but someone with low life chances will likely have a consistently low standard of living. The term for a person’s ability to change their economic status in a society is known as social mobility.

When families have low social mobility, they may become trapped in poverty for generations; we refer to this as the cycle of poverty. Typically, these families have either limited or nonexistent social and economic resources. There are many disadvantages that collectively work in a circular process to make it virtually impossible for individuals to break the cycle of poverty. They are less likely to have financial capital, education, job skills, reliable transportation, and social capital (connections to people with specialized knowledge or in power). Without these resources, poverty-stricken individuals experience disadvantages that, in turn, increase their poverty.

Additionally, those living in poverty suffer disproportionately from hunger, poor nutrition, and exhibit disproportionately high rates of physical and mental health issues. These illnesses can be disabling, preventing people in poverty from working, thus reducing one’s opportunities to improve their social and economic status.

Finally, poverty increases the risk of homelessness. People who are homeless have low access to neighborhood resources, high-status social contacts, or basic services such as a phone line, limiting their ability to improve their economic position, again perpetuating poverty.

Culture

Culture is often referred to as a blueprint or guideline shared by a group of people that specifies how to live. 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, churches, media, friends, and others throughout a lifetime. The kinds of traditions and values that evolve in a particular culture serve to help members function in their society and to value their society. We tend to believe that our own culture’s 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 a crucial 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. So much of what developmental theorists have described in the past has been culturally bound and difficult to apply to various other cultural contexts. For example, Erikson’s theory that teenagers struggle with identity assumes that all teenagers live in a society in which they have many options and must make an individual choice about their future. In many parts of the world, one’s identity is determined by family status or society’s dictates. In other words, there is no choice to make.

Even the most biological events can be viewed in cultural contexts that are incredibly varied. Consider two very different cultural responses to menstruation in young girls. In the United States, girls in public schools often receive information on menstruation around 5th grade, get a kit containing feminine hygiene products, and receive some sort of education about sexual health. Contrast this with some developing countries where menstruation is not publicly addressed, or where girls on their period are forced to miss school due to limited access to feminine products or unjust attitudes about menstruation.

Multidisciplinary

Any single discipline’s account of development across the lifespan would not be able to express all aspects of this theoretical framework. That is why it is suggested explicitly by lifespan researchers that a combination of disciplines is necessary to understand development. Psychologists, sociologists, neuroscientists, anthropologists, educators, economists, historians, medical researchers, and others may all be interested and involved in research related to the normative age-graded, normative history- graded, and nonnormative influences that help shape development. Many disciplines contribute important concepts that integrate knowledge, which may ultimately result in the formation of a new and enriched understanding of development across the lifespan.

References:

Cowan, P.T. & Kahai, P. (2022). Anatomy, Bones. StatPearls. Licensed under CC-BY-NC-ND 4.0

Mathern, G.W. (2010). Cerebral Hemispherectomy: When half a brain is good enough. Neurology, 75(18). DOI: https://doi.org/10.1212/WNL.0b013e3181fb4501

Story, S. (2018). Rhythmic Movement Training International (RMTi) curriculum: Evidence based rationale and relevance to occupational therapy practice. https://www.moveplaythrive.com/image...evance_RMT.pdf

Tamashiro, K.L.K., Terrillon, C.E., Hyun, J., Koenig, J.I., & Moran, T.H. (2009). Prenatal stress or high-fat diet increases susceptibility to diet-induced obesity in rat offspring. Diabetes, 58(5) 1116-1125. https://doi.org/10.2337/db08-1129

Attributions:

Child Growth and Development by Jennifer Paris, Antoinette Ricardo, and Dawn Rymond, 2019, is licensed under CC BY 4.0

[1] Lifespan Development: A Psychological Perspective by Martha Lally and Suzanne Valentine-French is licensed under CC BY-NC-SA 3.0 (modified by Jennifer Paris)

Child Psychology by Nicole Arduini-Van Hoose is licensed under CC BY-NC-SA 4.0

OpenStax College, CC BY 3.0, via Wikimedia Commons

Domains in Lifespan Development, July 28, 2020 on YouTube by Prof Newton