The child is father to the man. This saying seems so obviously true that it may surprise some people that it needs to be analysed and certain assumptions inherent in it need to be challenged if psychiatric practice across the lifespan is to be properly informed by findings from developmental psychology. This chapter examines different conceptualizations of children and childhood through the ages and the ideas and theoretical models that have shaped popular, as well as professional, views on how children develop. It notes that there are no overarching theories of child development, but rather a pot-pourri of smaller models, most of which address disparate aspects of development.

Developmental psychology is not just about charting the norms of development, although knowledge of such is essential in all clinical practice. Rather, there are many issues that need to be critically examined in trying to understand how individuals develop. Taking a developmental perspective is about integrating this knowledge and understanding the patient’s presenting problems within such a framework.

The significance that the clinician will place on a particular piece of behaviour will depend not only on the child’s sociocultural background, but also on the child’s developmental age. Cox and Rutter⁽¹⁾ note four reasons for taking a developmental perspective:

1 Children behave differently at different ages. The clinician must be familiar with the range of behaviours and their age-appropriateness in separating the normal from the abnormal. For instance, simple consonant substitutions are widespread in the speech of pre-school children, but indicate some delay or deviation in the speech of teenagers.

2 Many aspects of behaviour can be viewed as progressing through a normal sequence. Admittedly, discrete stages are overemphasized by stage theorists such as Freud, Piaget, and Bowlby, whereas the continuities in development are more emphasized by social-learning theorists such as Staats, Bijou, and Baer. Either way, an understanding of the normal sequences and ages permits a judgement as to whether the child has deviated in his or her development.

3 Different stages of development are associated with different stresses and different developmental tasks. Bladder and bowel training are normally achieved between the ages of 2 and 4 years. Major stresses on the child or the family at the time may interfere with the achievement of proper bladder and bowel control. Mood swings are very common in adolescence, making it difficult to diagnose the severity of depression at this stage.^{(2, 3)}

4 An understanding of the processes which underlie both normal and abnormal development will help in the understanding of how the problems have arisen.⁽⁴⁾ Such an historical perspective can help explain to the parents why a particular problem developed, as well as give possible clues for future programmes for prevention. A major implication of this for clinical practice is that it is always necessary to obtain a good account of the child’s developmental history.

5 A better understanding of the processes underlying a child’s development will lead to far better interventions and prevention.
Once we have a better understanding of the distal and proximal causes of behaviour, better targeted interventions will follow.

There is a bewildering set of mini-models and mini-theories of developmental processes, each trying to deal with changes in children’s functioning either at different periods in their lives or in different psychological functions such as perception, language, and memory. By and large, the different theories seem to ignore each other’s work—and many also seem keener on theories than on data that might test the theories.

For example, Piaget’s theories predominantly address how children develop a cognitive understanding of their world. His was a biological view of development, and his cross-sectional methodology emphasized the separation between the stages he posited. Staats⁽⁵⁾ argued that most of the phenomena described by Piaget and his followers could be interpreted within a social learning theory framework that instead emphasized the continuity of development across stages.

Kohlberg’s theory of moral judgement is a stage theory that differs radically from Piaget’s in that the different forms of reasoning said to typify different stages can coexist. However, the way in which children (or adults for that matter) judge an ethical dilemma does not necessarily determine how they behave. Most financiers would have little difficulty in providing sophisticated moral judgements on Kohlberg type tasks, but many financiers also present the unacceptable face of capitalism in their ruthless dealings. It is not the case that the older we are, the wiser we behave.

In Freud’s theory of psychosexual development, children are seen as passively passing through stages, their development being impeded by obstacles or even regressing in the face of trauma. This view owes more to literature than to science, and the evidence on children’s psychosexual development clearly shows that whatever Freud was unaware of during the latency period, children are certainly far from inactive.⁽⁶⁾

Apart from being stage theories, these three sets of influential theories really have very little in common. The psychological mechanisms determining growth of cognitive understanding bear little relationship to any that supposedly underlie socio-emotional behaviour. None of the theories take into account all of the work done in perceptual development, language development, development of memory, development of peer relationships, development during adolescence, and so on. They pay little attention to the work on individual differences in personality or temperament, or to biological development generally.

A totally biological, determinist view of development was anathema to the new theorists of behaviour modification and behaviour therapy in the 1960s. It was seen as too pessimistic, offering little hope of change. By ignoring the biological basis of behaviour and seeking explanations solely in the here-and-now (proximal) influences on behaviour, they undoubtedly broke through to a much more optimistic era of interventions.

Simultaneously, child developmentalists were recognizing the contributions the child brought to all aspects of development. The child has increasingly been seen as an active participant in development. The direction of influence was not all one way: the child helped shape the environment. Thus, parents react to individual differences in children. Different children call out different responses from their social environment. As parents have known all along, children do have different temperaments from birth, and these shape how they develop.^(7,8)

The implications of this for child psychiatry are many. For example, it implies that clinicians must take into account a child’s temperament when planning treatment.^(7,9) Children who are extremely introvert react differently to praise and punishment than children who are extremely extrovert.^(9,10) They also respond to different teaching styles in the classroom. Such differences need to be accommodated in setting up individualized treatment programmes.

With young infants, it can be very reassuring to a parent to be told that anyone would find their unpredictable child difficult to rear. It can boost parental self-confidence to be told (when true) that their parenting style is perfectly adequate for most children— just not effective with this particular one. This reassurance should greatly alter the way such a parent participates in parent training programmes that are increasingly part of primary and secondary level child mental health services.⁽¹¹⁾

All this is not to say that stage theories carry no implications for child mental health services. Far from it. It is very helpful to remember that young children think and reason about their worlds differently from older children. This has to be borne in mind when interviewing children, when trying to elicit their own understanding of their problem, and, equally, when giving them instructions, feedback, or explanations. However, it must again be emphasized that the stages should only ever be regarded as rough guidelines. We know that there are such wide individual differences in the rate at which children develop that we should never make assumptions about the individual child knowing only his chronological age.

Let us take one example that increasingly confronts clinicians— the issue of helping children deal with bereavement. It is not until around the age of 10 or 11 that most children appreciate that death is both universal and irreversible.^{(11, 12, 13 and 14)} This helps explain why some younger children show an almost casual, matter-of-fact interest in death of a loved one and are less upset by it than adults are.⁽¹³⁾ But it would be wrong to assume that all younger children fail to have an adult appreciation of the significance of death, and indeed some children as young as 4 years old have been found to have a mature understanding. Knowledge of the broad outline of the development of the conceptualization of death helps clinicians formulate their questions, but the onus must always be on the clinician to check whether or not the individual child conforms to the average. The adult’s task may not be finished when they have helped a young child to understand bereavement at the level the child can cope with. That same child will probably want to revisit the issue when she is older and can understand it in a more mature way.⁽¹⁵⁾ What is true of bereavement also holds true for understanding any other major life event and its effects on the child.