Welcome to the first lecture of the course “Understanding development from synapse to society”. In this lecture I will first go into the question: “What is development?”. You will see that there is much disagreement about this complex issue. Next, I will help you understand development from a developmental systems approach. This approach will be adopted throughout the course. I explain this approach using two influential theories. I explain these theories because they can help you organize your thinking about how various interacting factors can influence development at multiple levels of organization, from synapse to society. So let’s start with the question: “What is development?” Most developmental scientists will agree that development implies systematic and successive change.
Unfortunately, this is where the consensus ends. Therefore, there are no “facts” regarding development. Only interpretations in the context of the particular theory or perspective a scholar adopts. Historically, a number of issues regarding development have been heavily debated, and strongly influenced theory. Here I will focus on one particular issue that has colored perspectives on development for over 2000 years: The extent to which development is determined by nature, our genes, or nurture, the environment.
According to the developmental systems approach nature and nurture continually interact and through this interaction contribute to development. Nature never affects development directly, it always acts in the context of the internal and external circumstances. Similarly, effects of the environment on an organism will depend on the heredity-related characteristics of that organism. It is important to realize that this also implies that asking yourself in what relative proportions nature and nurture contribute to a given behavior is fruitless. Nature and nurture are not independent and additive. They are inherently fused.
The idea that the course of development is not set in stone (or our genes), but depends on a continuous interaction with the environment has great applied significance: If you don’t believe that development can be influenced by the environment, it makes no sense to devise interventions to support development. The developmental systems approach argues that development can be influenced. This also implies that there is not one course of development. Children grow up in distinct contexts – unique combinations of personal and environmental circumstances that can result in different paths of change.
The challenge then, is to understand how, where and when we can best intervene.
All this complexity is captured by the developmental systems approach. In summary, this approach assumes that development is influenced by interacting factors at multiple levels of organization.
Now that we have discussed the general idea of what development is according to the developmental systems approach let’s go into a bit more detail. I will now discuss two influential developmental systems theories. These theories are relevant because they can help you organize your thinking about how various interacting factors influence development at multiple levels of organization.
The first theory I will discuss, was introduced by Uri Bronfenbrenner, a Russian-born American developmental psychologist. Bronfenbrenner called his model the bioecological model. It describes how development is molded by a child’s biologically influenced dispositions in interaction with influences from its surroundings, the ecology.
According to this theory, the environment is a complex system consisting of interacting layers, or nested systems, that together affect development. The model distinguishes 5 subsystems each of which I will now briefly discuss.
The first system is the microsystem. This system is the innermost level of the environment and consists of activities and interactions of the child with its immediate surroundings. Examples are the interactions between the child and his parents at home, or between the child and a teacher at school. It is important to note that the bio-psycho-social characteristics of the individuals in such interactions, are part of the micro-system. Interactions between a child and a teacher, for instance, will depend on characteristics of the particular child and characteristics of the teacher. Individual differences or developmental changes in these characteristics influence the nature of the activities and interactions in a particular microsystem, and vice versa.
In day-to-day life individuals move through various micro systems.
The second system is the mesosystem. This system encompasses connections between all the microsystems related to an individual at a given moment in life. For instance, when parents are involved in school life and exchange experiences and information with school, development in both settings can benefit. Academic learning can be carried over in the home, and knowing what is going on at home may improve teacher-child interaction. The mesosystem also includes stable features of people in the immediate surroundings of the child, such as their Social-Economic-Status.
The third system is the exosystem. This system refers to social settings that do not contain children but nevertheless affect children’s experiences in immediate settings. Examples are parents workplaces and health and welfare services in the community. Parents work, for instance, may facilitate special leave when children are ill, but can also cause stress that affect how parents respond to their children at home. Another example is parents social network for providing advice, and social companionship. All these factors indirectly affect the child.
The fourth system is the macrosystem. This system consists of cultural values, laws, customs, and resources. The priority that the macro system gives to a child’s needs affects the support they receive at the more proximate levels of the environment. For example, a country may have laws regarding paternity and maternity leave, or the standards of child care, which will impact on the lives of individual children in that country.
The final system is the chronosystem. This system refers to the continuous influence of time on all other subsystems and their interactions. Indeed, change over time is a defining characteristic of development. Time influences children at the individual level, in terms of their physical, intellectual, and personality characteristics. Time also influences the developmental challenges and opportunities that affect children at the various levels of the environment. For instance, the arrival of a new sibling has very different consequences for a home bound toddler compared to a school-age child with many relationships and activities beyond the family. In this example the timing of an environmental change affects its impact.
So how can the theory of Bronfenbrenner help you organize your thinking about development? It does so by providing you with a clear framework for ordering and structuring the great myriad of factors that can influence development. As such it can help you to keep an overview.
However, the strength of Bronfenbrenner’s theory is mainly in describing how environmental influences can be organized at various levels. Therefore, I will also discuss a theory with more emphasis on the levels within the individual. This theory was introduced by another American developmental psychologist, Gilbert Gottlieb, and is called the model of Probabilistic epigenesis .
This model describes how genetic activity, neural activity, behavior, and environment are all bidirectional related.
The term “epigenesis” refers to a change in genetic expression as a result of environmental influences. Gottlieb argued that the emergent products of development are epigenetic, not just genetic. Although this idea is now widely accepted, it was highly controversial when Gottlieb first introduced the idea. He included the term “probabilistic” in the name of his model to indicate that the developmental outcome of certain influences is often not certain as it depends on so many different factors. Thus, specific gene-environment interactions may increase or decrease the probability of development in a certain direction.
In his model the most basic level of organization is that of gene activity. Genes provide the blueprint of the organism from which proteins are constructed in the cells. Genetic activity thus refers to the kind and amount of proteins that are made. Proteins do most of the work within cells and are required for the structure, function, and regulation of the body’s tissues and organs. As such, genetic activity gives rise to neural and other structures, which allow us to function and interact with the environment. Conversely, genetic activity is influenced by each of the three other levels: neural activity, behavior and the environment. So, the model proposes bidirectional relations within and between the four levels or organization. In addition, these relationships are assumed to be dynamic: they may constantly change over time.
Gottlieb argued that taking into account the dynamic bidirectionality of influences between levels is a prerequisite to ever successfully link genes and nervous systems to behavioral outcomes.
What I just discussed are two examples of developmental systems theories. Many more of such theories exist, that all stress the importance of including multiple levels of description when trying to understand development. And because of the implied complexity, all of these theories stress the need for interdisciplinary collaborations to attain a meaningful understanding of development.
The major implication is that it is useful to search for characteristics of people and their contexts that, together, can influence the design of policies and programs promoting positive development.
This is an effort that goes well beyond science alone and bears relevance to everyone who is interested or involved in fostering optimal development of children in one way or another.
In this lecture I have explained how development can be understood from a developmental systems perspective. In addition, I explained two theories that describe systematic ways of composing various influences on development at multiple levels of organization inside and outside the individual. This provides you with a framework for appreciating the complexity of development, during this course and beyond.
In the next lecture I will explain what it takes to study development from a developmental systems approach.
