Introduction

Numerous theories and stage models have been proposed to describe the years of life from birth to adolescence (Damon & Lerner 2006, Harms 2005). Rather than learn these exhaustively, it is more important to understand the broad changes that can be observed across these years when watching children. These observable changes contributed to what researchers have proposed are important for health professionals to remember when working with children.

When comparing a two-year-old child with a 12-year-old child there are enormous differences in almost everything about their life situation and their behaviour. It is these monumental differences that prompt researchers to propose their theories and stage models. Researchers and theorists observe the changes in activities and processes that occur as children develop and then try to describe these. When learning about developmental theories, avoid focusing solely on learning the theories; it is important to learn what the theorists were observing, reacting to and trying to describe in their theories. To help with this, complete Classroom activity, Exercise 1.

Clearly, there are many changes taking place as a child develops. While this may seem obvious, it was not that long ago that children were viewed as ‘little adults’ with the same cognitive, emotional and psychological abilities of adults, although maybe not all the physical abilities. Theorists have attempted to simplify the many details of changes throughout childhood and adolescence and to explain how the changes take place. How various theorists have attempted to do this has varied and focused on various aspects of development.

Types of theorising about development

There are many ways to categorise theories: reductionistic, mediational, deterministic, essentialistic, causal, contextual, explanative or descriptive. A reductionistic theory, or reductionism, is a theory in which complex things are reduced or understood in terms of basic, simplified elements. For example, risk-taking behaviour of adolescents would be understood in terms of brain development in a reductionistic theory. Specifically, research has shown that the prefrontal cortex, which is considered to be the site of higher-order cognitive functioning (i.e. the ability to think things through), is not yet fully developed in adolescents (Nelson 2003). A mediational theory is somewhat similar to reductionism but the key element in mediationism is that a behaviour or concept is mediated by something else. Using the example of adolescent risk taking, a mediationist would say that brain development mediates risk-taking behaviour. Another example would be that an adolescent who is observed to be sleeping excessively, lacks interest in things they used to enjoy and spends a lot of time alone is then considered to be depressed, such that depression is then seen as the mediator of these behaviours. This is an important distinction because it influences how we then go about intervening or what we do to change the behaviour. Do we change the sleeping, lack of interest, the time spent alone or the depression?

Determinism is a theoretical approach in which the behaviour we observe is determined by past history: history of relationships (e.g. parental relationships in the case of Freud) or in history of consequences of behaviours (in the case of the behaviourism of B F Skinner discussed later). Using the above examples, risk-taking behaviour may be explained in a deterministic way by referring to the history of consequences of behaviour, specifically, that risk-taking behaviour has been positively reinforced, perhaps by getting attention. In contrast, essentialism views characteristics of groups (e.g. groups based on ethnicity, gender or age) as fixed or unchangeable, so, risk taking by adolescents would be seen as an essential quality or characteristic of adolescents that is not changeable or influenced by context.

Causal and contextual theorising can be understood together by contrasting them. Causal theories look to understand exactly what it is that causes what we observe while a contextual theory looks to understand the contexts of behaviour. Again, for adolescent risk-taking behaviour, we could say that brain development causes risk taking or that risk-taking behaviour is more likely to occur in contexts of groups of youth in unsupervised situations, for example.

Finally, explanative or descriptive theories can also be understood by contrasting them. They are similar to causal and contextual theorising with an explanative theory similar to causal explanations and descriptive theories similar to contextual explanations. Using the depression example, we could refer to physiological deficits (e.g. low serotonin levels) to explain why an adolescent is depressed, or we could describe the contexts (especially social ones) in which depressive behaviours are more or less likely to occur.

All these theoretical approaches are not mutually exclusive and refer to different perspectives. Most theorists develop a view based on their own experience in the same way you did in your classroom exercise.

In this chapter we will refer to only one major difference between theories: whether changes that arise with age are explained by something within the person and their body (reductionism, mediationism, essentialism) or because of forces outside of the person (contexts or determinism). While most theorists today look for a mixture of these types and do not rely exclusively on one or the other, this distinction will help to understand what the original theorists observed and tried to explain.

Sigmund Freud is probably best known for his theories of psychoanalysis but the broad idea he championed and strongly argued was that events that occurred in childhood determined a lot of behaviour patterns later in life (Freud 1917, also see Chapter 1). In his clinical practice, Freud talked to many hundreds of people and believed there was a pattern in which some serious events in people’s early history made them into a certain type of person that continued later in life. This was connected to key events in childhood, he thought, such as learning to control eating, drinking and defecating (potty training), learning about genitals and learning the rules about them (‘you are punished if you touch them’) and learning about family control – which was almost completely controlled by the father in Freud’s day, at least for the sorts of families he dealt with.

Freud believed from his experience with people that these key events in childhood made people into a certain type of person (that is, their ‘personality’) and this led to various peculiarities that he could detect when talking to people with serious clinical issues later in life. For example, someone who had trouble potty training might develop into someone who tended to obsess about things later in life. If a person’s obsessiveness became serious to a clinical extent then Freud’s psychoanalysis would involve talking about obsessiveness as well as their early childhood history (including ‘potty training’) in therapy sessions.

Burrhus Frederick Skinner (Fred) (1938, 1957, 1969) was a famous psychologist who mainly worked with animals. What he found fascinating was that minute details of the animal’s environment (primarily their cages and the lights and switches in their cages) could be shown to change how the animals behaved. Skinner’s theory, known as radical behaviourism, includes and elaborates on the basic concepts of antecedents (environments, contexts or stimuli), behaviour and consequences (what happens when a behaviour occurs). For example, rats that, when a light is on (antecedent or stimuli), had to press a lever (behaviour) more than once to get food (consequences) (as is the case in fixed or variable schedules of reinforcement) would persist in pressing the lever longer when the food supply was stopped (called extinction) compared with those rats that got food on every press they made (i.e. in continuous reinforcement). Skinner was impressed that these small and not easily observed changes in the animals’ environment could make a large difference to their behaviour. Figure 2.1 shows how antecedents (or the environment) can influence behaviour that then leads to a consequence. These consequences contribute to both changing the environment as well as changing behaviour.

Figure 2.1 How antecedents (or the environment) can influence behaviour, leading to consequences

These observations led Skinner to push for a theory that almost all behaviour was determined or controlled by factors in the environment rather than something that seemed to be ‘stored’ inside the body or what was ‘made into your personality’ (i.e. Freud’s approach or mediationism). Skinner found that he could change the environment for his animals and watch their behaviour change subtly and in precise and predictable ways. This means that for any behaviour changes observed, we need to examine and describe the environment very carefully for the details that might be controlling that change or influencing the behaviours observed.

When applying this to humans, opinions are divided. One perspective is that such environmental factors do not apply to humans since we often do things but nothing can be found in the environment that might have changed. The other perspective says that we are not looking hard enough for these factors and that they might be observable but have occurred in the earlier history. For example, using the depression example above, we might not be able to see anything in the immediate environment that can explain the behaviour, so we say that the person is ‘depressed’ but it may be that past events contributed to the development of depression and that other factors then contribute to the maintenance of the behaviours we then call ‘depression’. According to Skinner, it would be possible (although often very difficult) to discover environmental changes that contribute to all human behaviour.

Skinner’s work and observations with children and human participants was mostly in relation to his own children. Perhaps his best known work with children was his development of an air crib for his own child. Skinner believed that a highly controlled environment would eliminate the mundane tasks of baby care such as keeping them warm and clean. In this way, parents could more effectively (and would have more time to) engage in other aspects of parenting such as playing and reading.

B F Skinner’s original air crib can be viewed at: http://www.coedu.usf.edu/cybertutorial/images/babyinbox.jpg.

The original testing ground for Skinner’s ideas about human behaviour in research was looking at what controls our talking and use of language (Skinner 1957). Some said that no observable environmental changes could be seen when children start talking or using language in subtle ways but Skinner said that we have not been looking in the right places. Although his version of how we might look for environmental factors was not well received (e.g. Chomsky 1959), newer versions of Skinner’s ideas have been developed (Andresen 1990, Catania 1997, Hayes et al 1994).

Jean Piaget (1952, 1954, 1962) was the most famous psychologist to look at how children think (cognition) and speak (language). He was not looking for environmental factors but was more interested in theoretical ideas of ‘information processing’ centres and ‘cognitive processes’ in the brain.

Like both Freud and Skinner, Piaget spent a lot of time observing behaviour, particularly by participating in thinking games with children, in order to develop his theories. Many researchers no longer do this and rely on questionnaires administered from a distance and often only once. Much can be learned from these great early theorists. Understanding children requires spending a lot of time systematically observing them and participating with them. Imagine someone who studies trees but never actually spends time trying different things (pruning them, adding new fertilisers, more sunlight) and observing their growth. The situation is the same with understanding children and, unfortunately, some ideas are developed and research conducted by people who have not spent much time with children.

Piaget observed that children of different ages seemed to think in very different ways from each other. What he saw was not like a continuum of thinking from simple to complex but a set of stages. For example, he observed that very young children did not seem to be able to think in terms of causality – that one event can cause another event. It was not that the children had different causes for the same event but, rather, they did not seem to be able to think in terms of causes at all. Causality was not thinkable below a certain age. Piaget observed older children start to explain what caused events, naming events and objects that might have caused something else and trying to justify the way things occurred the way they did.

These observations led Piaget to argue for a stage model in which children learn more and more complex ways of thinking and are even not able to think in one level until they had achieved the level before that in the sequence. He also argued, from his observations, that once a certain stage of thinking was reached this had consequences for what the child could accomplish; that led to even newer talking or cognitive developments. For example, once a child could think in terms of causality – that events cause other events – then they could think in terms of making excuses and getting themselves out of trouble. ‘I only did it because Giles told me to’ needs a level of causal thinking before it can be thought at all.

While Piaget had a number of stages and substages of cognitive development, here we focus on the overall changes he noticed. (You may like to refer to a developmental psychology textbook such as Peterson 2004 for more details.) The first broad stage he called sensorimotor because children at this age think, as it were, through their senses and their physical movements. Something like, ‘If I can’t see it, taste it or touch it then it does not exist and I cannot think it!’ Children explore and learn only what they physically interact with thorough their senses. At this stage, children cannot ‘think’ a cat being somewhere else if it is not in front of them, or they are not touching it, or they do not have its tail in their mouth.

At the preoperational stage children begin to have words for the things around them and use those words but this stage is ‘pre’ operational with ‘operational’ referring to ‘logic’. This is not just being able to reliably say a sound when something is there, as even very young children can say ‘caaa’ when a cat is presented. It is the beginning of ‘representing’ things by words so that the child can also say ‘caaa’ when the cat’s box is there or ‘caaa’ when a parent gets the cat’s food out of the cupboard.

One interesting thing Piaget found for children at an early age was that if, say, a cat was hidden under a blanket, the child would act as if the cat had gone for good and was no longer in existence – ‘out of sight, out of mind’. However, as a child develops, they will begin to look under the blanket for the cat, that is, the object has permanence even if it cannot be seen. Piaget called this developmental aspect object permanence. Around the same time children would also begin using the word ‘caaa’ in the preoperational sense explained above. These were the sorts of real changes Piaget noted and that he was trying to capture in his theories and stages. Whether the learning of words led to the cognitive skill change or vice versa is a moot point but the overall changes are common and very noticeable.

From this preoperational stage of beginning to ‘see things that are not immediately there’ and being able to talk about things not in front of you, a good cognitive ability needs to be able to reason and to classify and code. In the concrete operational stage the child begins to use logical forms of reasoning (note that there are several main systems of logic, not just one) and to classify things into groups based on characteristics. However, these processes are only for concrete things and events, such as ‘my trucks’ or ‘Gracie got an ice cream, why can’t I have one?’ rather than anything more abstract.

The ability to complete complex tasks or abstract ways of thinking arise in the formal operational stage in which abstract thinking is possible and can be used in reasoning and logical processes. Piaget, as well as other child development researchers, devised a number of tests to determine development at this stage and it is not so much the resolution to these tests that is important but, rather, how children come up with the resolution. For example, to combine a yellow solution with a blue solution to create a green solution, a child in the concrete operation stage may, through trial and error, mix the solutions together. However, a child in the formal operational stage may use logic to come up with the answer before using trial and error.

Typically, the ages associated with these stages are: sensorimotor 0–2 years, preoperational 3–7 years, concrete operational 8–11 years and formal operational 12–adulthood. However, these have been found to vary depending upon the education system and the context of the child. What is important is that vast changes are taking place in the very way children think and talk about things through these ages and this is what Piaget observed through intense observations and then tried to put into a formal theoretical structure. For us, whether the latter is exactly correct or not is not so important and learning the real changes is what matters most.

One thing Piaget did consistently was to focus his observations and theorising on individual children thinking and talking about events and treated the stages he saw as changes in internal information processing or the ‘structure’ of cognition. Lev Vygotsky (1978), a Russian theorist in the early 1900s, was the first of a series of theorists who, like Skinner, undertook research that looked for environmental or external factors that might be controlling the changes that appeared to occur ‘within’. However, Vygotsky did not know Skinner’s work even though it came earlier; Vygotsky’s work was not known in English-speaking countries until much later.

What Vygotsky and others suggested was that the ‘hidden’ environmental factors that bring about developmental changes but which are hard to see, are social ones – that is, the so-called internal cognitive changes and stages depend upon social relationships – hence, his theory is known as a sociocultural theory. The idea from this was that the ‘mind’ and the ‘cognitive processes’ were in fact controlled by social factors that were very subtle and not easy to observe unless you observed closely and over a long period. According to this line of thinking, the mind is not inside the body; rather, it is a name for processes of social interaction that cannot be directly seen and which occur over time.

Rather than think and talk about children ‘having’ or ‘possessing’ skills (whether physical or cognitive), Vygotsky wrote about how children think in the context of development, especially social context. He did not talk or theorise about children learning to think in ‘stages’ set apart from their social interactions, conversations, modelling and other social experiences.

This sort of idea, looking at social influences on what seem to be purely ‘internal’ thinking events, has been developed in various ways, from looking for patterns in social relationship thinking that facilitate thinking about causality or mathematics, to looking at how social support, encouragement or training facilitates cognitive thinking. We still have some way to go in describing the finer details of these approaches (Guerin 2001, 2004).

Vygotsky’s ideas often become clearer to people in the context of his notion of zone of proximal development (ZPD). Rather than conceiving of children reaching new stages of cognition and thinking as changes taking place inside them somewhere, the changes occur within interactions with other people, through processes of imitation, cooperation, support, guidance, enrichment, etc. If we act totally alone then there are many things we cannot do and cannot easily learn to do – this is the lower limit to the ZPD. If we act with other people in concert or in support, we can do a lot of things by accepting the other person’s responsibility and help – this is the upper limit of the ZPD.

Therefore, there are skills we learn through others and, perhaps, when they are not present, we can no longer do those skills. Eventually, as we get older, we can do more without other people’s direct involvement. But this Vygotskian way of thinking means that skills are not absolute, all or none possessions that once we get them we cannot lose them. We lose skills as well as develop them and we have a variable set of skills that we sometimes have and sometimes not.

We can apply these ideas to children and physical activity and how that can change depending on the people the children are with and the contexts. For example, learning to ride a bike may develop with help from parents or older siblings. Riding without training wheels may start with someone holding on to the seat and letting go when the rider is not aware but this skill may depend on the presence of others until the skill refines. Eventually, riding a bike may develop into very complex skills such as with friends at a bike park. But, after not riding a bike for a long time, a child would not be able to go straight back to the bike park and perform all the tricks again. Even though we may be able to ride a bike even after a long period of not riding one, some of the finer skills would require practice to re-learn.

The Vygotskian answer to the question of ‘What cognitive stage is that child up to?’ is: ‘Well, it depends on who that child has been interacting with and has been supported by. By themselves they might not be showing too many thinking skills but when interacting with a parent or a favourite carer or teacher they might show remarkable cognitive prowess’. In essence, the answer is in the environment (social environment), not inside the child.

Some recent approaches to describing human development have set similar ideas within multidimensional approaches. This means that human biology, social factors, psychological factors, spirituality, structural issues and culture are all considered when trying to understand human development (Harms 2005). Some call these approaches biopsychosocial models, ecological approaches or contextual approaches. What they all try to encapsulate is that human development is obviously made up of lots of changes, that most of the determinants of these changes are difficult to observe easily and that the changes all involve the body, the environment and the social world. We do not yet know how these elements might all fit together but these approaches are sure that we must have them all as ingredients.