Research report no.8 2002

Children's health and development: new research directions for Australia

edited by Ann Sanson

2. The relevance of child and adolescent development for outcomes in education, health and life success by Graham Vimpani, George Patton, Alan Hayes.

There has been a broadly-based renewal of interest in the importance of early human development over the past few years. A range of factors has contributed to this renaissance.

First, there have been concerns across many disciplines about deteriorating indices of the adjustment of children and young people, presumably in response to social and family changes (Fukuyama 2000). It has also been increasingly recognised that the influence of socio-economic inequality on a range of adverse life outcomes begins in the early years of life, through its impact on environmental experiences such as stress, parenting and nutrition. As well, it is becoming apparent that many of the problems of adult mental health, addictive behaviour, and crime have their roots in the experiences and environments encountered during early childhood, the most rapid period of human development.

Similarly, there is growing awareness of the importance of fetal programming in creating increased risks of adverse outcomes in adult life. Evidence has emerged from long-term follow-up studies that early childhood and adolescent intervention programs can have positive cost-benefit ratios, indicating the value of prevention and early intervention. Finally, a number of key reports have recently been published which highlight the importance of renewed social investment in the early years (McCain and Mustard 1999; Shonkoff and Phillips 2000).

This chapter summarises this background and flags the way in which a research partnership could advance our knowledge of the interplay between individual biology, experience, and environmental exposures, and could inform the policy debate on directions that might be taken to enhance early human development.

The 'great disruption'

There have been improvements in many health indicators - for example, falling perinatal and infant mortality, continuing increases in life expectancy, and reductions in death rates from many conditions as a result of technological advances (such as leukemia) or environmental interventions (road trauma). Despite this, other indicators of social health are less comforting. Examples include evidence of a relatively high rate of mental disorders and dysfunction in the recent mental health survey of Australian children and young people (Sawyer et al. 2000), the high rate of youth suicide, rising notification rates of child maltreatment, and concern about rising crime rates in young people.

Fukuyama (1990) has called the contemporary progression from an industrial to information and service-based society 'the great disruption'. This has been marked by many rapid changes in families and society that have been accompanied by deteriorating indicators of what Keating and Hertzman (1999) have termed 'developmental health and wellbeing'.

Some of the frequently cited social changes, and some of the deteriorating indicators of health and wellbeing with which they have been associated, include:

The impact of the 'great disruption' has perhaps been felt most acutely in deteriorating indices of children's and young people's health and wellbeing. Because young children's development reflects an interplay between genetic constitution and environmental experience, and is occurring more rapidly than at any other time in life, changes in their health and wellbeing indicators can serve as a warning to the rest of the community - not unlike the miners' canary - that humankind is not having a trouble-free adaptation to these changed societal conditions.

Some problems of developmental health and wellbeing

There is a range of health problems that affect children and young people disproportionately. Two of these - accidental injury and mental health - are among the six National Health Priority Areas identified by the Commonwealth, State and Territory governments.

The National Health Priority Areas initiative is Australia's response to the World Health Organization's global strategy on health reform. The initiative recognises that strategies for reducing the burden of chronic disease should work across the continuum of care, from prevention through to treatment and management, and be supported by a strong evidence base. These specific national health priority areas focus national collaboration on chronic diseases that: have potential for health gains and improved outcomes for consumers; pose a significant burden of disease; and have the support of all jurisdictions. The other four national health priority areas are asthma, cancer control, cardiovascular health, and diabetes mellitus.

Accidental injury

Injury, one of the National Health Priority areas, disproportionately affects young people - in particular, young males (NHMRC 1997). Accidents are the leading cause of death in 12-24-year-olds (60 deaths per 100,000 population at risk). Prevalence of injuries in young people is higher than in any other age group, and (apart from the 75 years and older group) death and hospitalisation rates are higher than for any age group. Injury deaths have dropped by around 60 per cent in two decades largely as a result of falling motor vehicle deaths. However, motor vehicle deaths and other transport accidents still remain overwhelmingly the commonest cause of accidental injury and death. Death from injury is around four times commoner in young males than young females.

Mental disorders and suicide

Mental health is another of the National Health Priority areas, and mental disorders also disproportionately affect young people. They are frequently associated with longstanding impairment and emotional and behavioural problems, and are therefore of great relevance to future health.

A 12-month survey of the practice profile of paediatricians in the Barwon region of Victoria in 1996-1997 found that 10 per cent of the childhood population had consulted a paediatrician practising in the community over this period. Thirty-five per cent of children seen had behavioural problems, with 76 per cent of these relating to Attention Deficit Hyperactivity Disorder, which was the most common diagnosis overall (Hewson et al. 1999).

The best available Australian information on 18-24-year-olds derives from the recent National Survey of Mental Health and Wellbeing (ABS 1999). In that survey the prevalence of mental disorders was 27 per cent in young adults, higher than in any other adult age group. Among young males, the commonest disorders were substance abuse disorders, affecting 22 per cent of 18-24-yearolds. For males aged 18-24 years, the commonest forms of substance dependence were alcohol dependence (12 per cent) and cannabis dependence (6.8 per cent). For females, point prevalence rates of depression were 14 per cent, with rates of 10 per cent for both anxiety and substance abuse disorders. Eating disorders may be viewed as a primarily adolescent disorder with an onset rarely after the age of 20 years. Anorexia nervosa has a prevalence of around 0.5 per cent and bulimia around 1 per cent of young women aged 15-25 years.

Among young people, mortality patterns associated with mental disorder have shifted in recent decades. Australia's male suicide rates have been consistently high over the past decade, with 1997 rates for males aged 12-24 being 24 suicides per 100,000, the fifth highest in the world. The highest rates in any age group are for males in their early to mid twenties (40 suicides per 100,000 per year). Mortality due to drug dependence has also increased markedly in the past 20 years in males and is now at the rate of six deaths per 100,000 in the 12-24 year age group.

Other health risks

There is also a range of adolescent health risks with major implications for future health.

Importance of developmental health and wellbeing

Keating and Hertzman (1999) coined the term 'developmental health and wellbeing' to describe the developing human organism's response to experiences and environmental circumstances. They contend that the 'physical and mental health, wellbeing, coping and competence of human populations arise in large part as a function of the overall quality of the social environment' (p. 3). They go on to argue for the existence of a strong base of evidence for the phenomenon of 'biological embedding of early experiences through sculpting of early brain development with impacts on the body's immune system and its response to stress' (p. 4).

Shonkoff and Phillips (2000) identified ten core concepts of early human development from a distillation of the findings of several generations of interdisciplinary developmental science research.

Consilience - the unity of knowledge

One of the phenomena of the last quarter century has been the convergence of evidence from many professional domains about the impact of early life settings on developmental health outcomes. For example, poorer cognitive, behavioural and emotional outcomes for children are associated with parental mental illness, especially maternal depression, and child abuse and neglect (Shonkoff and Phillips 2000). Many problem outcomes have their roots in early childhood experiences - risks for emotional and behavioural problems, and poor competence and coping, throughout the life cycle are established in early life; early disruptive behaviour is associated with greater risks of early and prolonged delinquency (National Crime Prevention 1999); and substance abuse risks are often related to early life experiences of parenting and disadvantage (Shonkoff and Phillips, 2000). Socio-economic gradients are well recognised in areas such as health, literacy and numeracy, and appear to be established early in life (Fonagy 1996; McCain and Mustard 1999).

Further, it is now widely accepted that the risks of some adult diseases (noninsulin dependent diabetes, hypertension, coronary heart disease) may have their origins before birth (Barker 1998). Studies have shown that measurements made at birth, including length and weight at birth, body proportions and placental weight, are related to increased risks of either later incidence of these diseases or to risk factors for them such as glucose intolerance, or hyperlipidaemia. It has been suggested that these associations are due to fetal programming: a programming stimulus in fetal life is proposed to lead both to changes in size at birth and also to altered homeostatic mechanisms, such as blood pressure regulation or insulin sensitivity, which in turn result in susceptibility to disease in later life (Barker 1998). There is good evidence that nutrition can be an important and potentially central programming stimulus (Harding 2001).

This convergence of understanding from many different fields has been termed 'consilience' by popular science writer E.O. Wilson (1998). It derives from an old English word meaning 'the unity of knowledge'. This is characterised by a 'joining together' of knowledge across disciplines by the linking of facts and fact-based theory to create a common groundwork of explanation. In the field of early human development, researchers, policy makers and practitioners from the social sciences, neuroscience, developmental psychology, early childhood, child health, mental health, public health and criminology are increasingly recognising the benefits of partnership in exploring causal pathways and developing and introducing interventions that will serve a mutuality of interests.

Impact of environmental experience on early brain development

The emerging field of developmental neuroscience is beginning to explore the extent to which the associations between early life and later adverse outcomes are mediated by experiential and environmental impacts on early brain development. However, the nature of the balance between the enduring significance of early brain development and the brain's impressive continuing plasticity remains controversial in the debate about the effects on the brain of early experience.

While abusive or neglectful care and growing up in a dangerous or toxic environment (for example, lead, alcohol) are manifest risks for healthy brain development, beyond these extremes the nature and boundaries of the environmental conditions necessary for healthy human brain growth are less well known (Shonkoff and Phillips 2000). Animal research on rats (Francis and Meaney 1999) and non-human primates (Suomi 1999), recent medical imaging studies in humans (De Bellis et al. 1999; Bremner and Narayan 1998), and follow-up studies of Romanian orphans reared in European homes (Gunnar et al. 2000) are pointing towards long-term psychological, structural and physiological changes related to the experience of early trauma and stress. What does seem important in the non-human studies is that caregivers' capacity to moderate the impact of stressful and fear-inducing circumstances on the infant's developing stress system has long-term benefits.

An important finding from longitudinal research on topics such as the emergence of criminal behaviour is that multiple opportunities exist for effective interventions at key developmental transition points (National Crime Prevention 1999). This is consistent with what we know of neural plasticity - namely, that the brain remains open to experiences across broad periods of development. However, what happens in early life is important, especially if sensory deficits impair the development of intact neural pathways (for example, vision). While animal research has shown that rats benefit from enriched environments, and that younger brains react more rapidly and strongly to environmental variation than older brains, the research evidence on human infant brains does not yet allow us to translate these findings into specific recommendations for early interventions for children (Shonkoff and Phillips 2000).

Key issues in understanding and promoting developmental health

While we have learned much about the ingredients for good developmental health outcomes, a range of unanswered questions persist. More coherent Australian policies and practices to promote better outcomes for children and young people need to be better informed by joined-up research across a range of disciplines. Research needs to address the causal pathways to good developmental health as well as the evaluation of what works under what conditions in Australian contexts. It is unlikely that in a diverse society such as our own, one size will fit all.

Need for more integrated and longitudinal research

Those concerned with promoting the science of prevention in developmental health need to learn lessons from the breakthroughs in biomedical science (for example, on the effective treatment of leukemia) which have involved multidisciplinary collaborations. To create the environmental circumstances that will impact on development, health and wellbeing outcomes, we need to learn from one another's research.

The observations made with respect to the prevention of substance abuse could be equally well applied to other outcomes. As Kumpfer et al. (1998: 79) state: 'Although more researchers are attending interdisciplinary conferences and reading journals of other fields, academically-based researchers tend to associate with colleagues from similar academic departments. Each discipline tends to view family problems from its own biomedical, psychological or sociological perspective. Researchers are all examining the multiproblem family, yet insights, findings, and solutions are rarely shared. In such cloistered circumstances, crossfertilisation of ideas is reduced, as is the application of different theories and methodological approaches to solving the growing real-life problems facing families in society... Researchers and practitioners specialising in substance abuse, rarely interact with prevention researchers in other fields (for example, delinquency, child abuse and neglect, special education, teen pregnancy, HIV/AIDS, runaway and homeless youth, child welfare, family support and early childhood education).'

Interventions aimed at improving developmental health need to be based on a sound theoretical basis, and longitudinal data are needed to monitor their impact. It is argued that one of the reasons for the growing awareness of the value of early intervention amongst funding bodies has been the emergence over the last decade of the results of some cost-benefit analyses based on longterm follow-up of individuals who had been exposed to interventions in the early years (Karoly et al. 1998) - see later.

Interactions of nature and nurture

The evidence emerging in neurosciences clearly points to the importance of both nature and nurture. Nurture affects genetic expression and the environment of cells influences which of the tens of thousands of genes are expressed to affect cell characteristics. As Shonkoff and Phillips (2000: 41) emphasise: 'It is time to reconceptualise nature and nurture in a way that emphasises their complementarity, not their distinctiveness: it is not nature versus nurture but nature through nurture.' High hereditability does not mean low malleability: 'environmental interventions can significantly improve developmental outcomes, even though individual differences in those outcomes may be strongly influenced by genetic processes' (p. 46).

Developments in molecular genetics and in the understanding of gene-environment interactions will not only increase understanding of the genetic basis for childhood disorders, but also indicate how genetic susceptibility may increase an individual's sensitivity to specific environmental influences. Those with a propensity to the development of a disorder may be buffered from its emergence if their environments are made more protective, for example, supportive, non-stressful family, school and community environments.

Role of parenting

Parenting style plays an important part in shaping developmental health outcomes. Sensitive and responsive parenting is fundamental to the establishment of a strong attachment relationship between children and their caregivers. The role of parenting and parent-child relationships is being increasingly recognised. Parenting is directly related to child maltreatment. Coercive parenting is associated with disturbances in the development of self regulation, increased risks of conduct disorder and later substance abuse. Authoritative, warm, consistent, communicative parent-child interaction and watchful monitoring provides the scaffolding to enable children to self-regulate their behaviour and feelings in a growing number of arenas (Shonkoff and Phillips 2000).

Parenting style also affects the development of literacy. There are clear class related and cultural differences in parenting style, with Australian and British research both finding that coercive parenting is more common in lower socioeconomic families (Zubrick et al. 1995; Fonagy 1996; Catalano and Hawkins 1996). There is anecdotal evidence of widespread ignorance about the vulnerability of young children to family circumstances, with some parents believing that the preverbal child is relatively immune to domestic upheavals like interspousal violence.

The 'goodness of fit' manifested when parenting style takes into account individual children's variability is also important. In view of the broad ramifications of parenting style for health and developmental outcomes, it is not surprising that some public health experts have claimed parenting is the 'major public health problem confronting modern societies' (Hoghughi 1998: 1545). However, while there is a range of promising interventions designed to promote sensitive and effective parenting, the universality of the parenting experience encourages the view that everyone is an expert, and many parents are reluctant to participate in programs that could increase parenting capacity.

Cultural influences

Culture has a major impact on early childhood development. Shonkoff and Phillips (2000) note that much of the research in the area is tied to values and personal beliefs, and identify a critical need for ongoing rigorous research in the area. Australia, with its mix of indigenous and immigrant cultures, provides a rich context for the study of cultural influences on developmental health and wellbeing.

Impact of non-parental care

The emergence of care and educational options beyond the family has been part of a revolutionary set of changes to the context of child development. Over 1.5 million Australian children under 12 years of age, or almost half of their age group, experience some type of formal or informal non-parental child care. Twenty per cent of children experience formal care. For many families, nonparental care is their only option in meeting their role in the workforce. The prevalence of child care suggests that the key focus of concern should not be on the possible adverse effects of child care, but rather on the consequences of not providing high quality care to children. The outcomes of child care are related to the quality of care received and how care settings link with the other contexts in which children develop (NICHD 1996).

The most striking characteristic of existing child care provisions is its diversity, meaning that children's care experiences vary markedly in content and quality. High quality care can enhance socioemotional functioning, cognitive abilities and school performance (Andersson 1989, 1992). Concerns have been raised, however, that early and extensive child care poses risks for infants on the basis of the theory that healthy development requires stable and continuous caregiving from one adult caregiver (Belsky and Rovine 1998). McGurk et al. (1993:19) have argued that a critical aspect of the ecology of the child care experience is the 'social, political and moral zeitgeist within which child care is embedded'. Again this highlights the importance of considering social context in understanding children's development.

Development is multiply determined by characteristics of the child, the family and care environment, and factors in the child's larger social environment. These factors operate in a complex and integrated fashion in influencing children's development. Child care is thus one of a complex of interacting influences.

Developmental outcomes of care reflect the inter-relationships among children's home environments, their individual differences, and non-parental care (Richters and Zahn-Waxler 1998; Howes et al. 1998). Recent research findings from the Competent Children Project (Wylie et al. 1997) found early child care services and home resources play complementary roles with regard to children's competency levels: 'Early childhood education service experience appears to nourish children's social, communicative, and problem-solving competencies in particular, while family resources may be important for children's cognitive competencies, as well as their social skills. Home activities were also associated with higher levels of cognitive competencies.'

In the United States and Canada socio-economic status has been linked with the type of care parents choose for their children (McKim et al. 1996). However in Sweden, where political support has led to the creation of a publicly subsidised daycare system of exceptionally high quality (Wessels et al. 1996), there is less correlation between the quality of care received and the socio-economic background of children (Howes et al. 1992). Cross-national comparisons highlight the importance of accounting for cultural and social influences on the child care experience.

In sum, child care occurs in the context of family circumstances and events as well as the overall pattern of care. Each context affects the other and can only be understood with reference to each other.

Influence of socio-economic inequality

There is a considerable body of research in Australia and overseas pointing towards the relationship between both poverty and socio-economic inequality, and adverse outcomes in developmental health and wellbeing. The extent to which these outcomes can be influenced by proximal interventions (such as intensive home visitation) as opposed to more global macrosystem changes requires further research. These have been explored in depth in a paper by Nicholson et al. (2000) for the Health Inequalities Research Consortium.

Impact of adverse community conditions

Neighbourhoods characterised by cultural diversity, high population turnover and physical deterioration produce cultural and social disorganisation which, allied to the easy availability of illicit substances, increases youths' vulnerability to substance abuse (Elliott and Menard 1996). Those communities marked by poor parental supervision are associated with higher rates of crime (Weatherburn and Lind 1997), and those marked by weaker connections between families and others in the community are associated with higher rates of reported child maltreatment (Vinson et al. 1996).

Challenge of educating policy makers and the public

The growing awareness of the importance of early human development for later life outcomes is reflected in some of the policies and strategies emerging at a state and commonwealth level, as well as among some of the more influential political thinkers (for example, Latham 2000). State programs such as Families First in New South Wales, Parent CARE in Queensland, and Building Blocks in Western Australia, and the Commonwealth's Stronger Families and Communities Strategy, are injecting new resources into measures to strengthen families and communities at a neighbourhood level.

There is a degree of policy dissonance between strategies such as this and more macro-level policies such as those pertaining to non-parental care. For example, the importance of non-parental care as a program to boost child development and improve educational and socioemotional outcomes especially for disadvantaged families, rather than just as a workforce support program, is not yet reflected in the level of support it receives from government and other sections of the community.

Much remains to be done to convince members of the general community, including many parents, that the family life experiences encountered by children in their early years have lasting impacts. There is also need for a better appreciation of the kinds of learning experiences that benefit children in their early years - learning the alphabet before school entry and access to expensive educational toys and software are far less important than the need for participation in self-directed exploratory play with peers, and the development of secure relationships with caregivers.

Perry (1996) argues that there is a serious mismatch between the paucity of social investment given to promoting optimum development during the early years, and the level of resources invested in later life to deal with the downstream problems of developmental health and wellbeing gone awry.

Capacity building within communities and workforces

It appears that the changes in community life associated with the 'great disruption' have meant that families with young children are facing many challenges alone (Fukuyama 1990). New support structures are needed to help communities confront the loss of social capital and community infrastructure associated with changes in the rural economy, workforce patterns, family structures and globalisation. Some of those incorporated in new government strategies offer much promise, but there has been little evaluation of their impact in the Australian setting.

The professional workforce is also challenged with the need to develop new operational paradigms - in health care, for example, from being 'the expert' and prescriber of therapeutic action, to facilitator and coach as well as evaluator and interpreter of diverse sources of information. A common challenge across many professional groups is the operational embodiment of the principles of consilience - the need for effective interprofessional and intersystemic collaboration at the local level to facilitate improved developmental health and wellbeing outcomes.

As Sawyer et al. (2000: xii) emphasise in relation to adolescent mental health: 'Adolescents with mental health problems do not have problems that are limited to a single aspect of their lives. Rather, their problems are wide-ranging and include suicidal ideation, smoking, alcohol and other drug use and abuse. There is constantly a need to develop joint policies and strategies across the different services that provide help to young people with mental health and related problems (for example, school-based services, paediatricians, family doctors, mental health services, and drug and alcohol services).' Similar needs, across different sets of services, exist for infants, toddlers, preschoolers and primary school aged children.

Shonkoff and Phillips (2000) have identified a need for decision-makers to take bold actions to design and implement coordinated, functionally effective infrastructures to reduce the long-standing fragmentation of early childhood policies and programs. They have also urged a comprehensive analysis of the professional development challenges facing the early childhood field.

Recognising continuities and discontinuities in development

The balance between cumulative risk and protective factors in early childhood establishes the bottom line for successive developmental transitions. At each stage of development, possibilities exist for intervening to minimise risk or enhance protection. For example, enhanced attachment can be promoted between mothers and temperamentally difficult infants (van den Boom 1994), parenting skills can be enhanced for toddlers and older children by skill-based behavioural programs such as Triple P (Sanders and Markie-Dadds 1996), and in older children the risks of some adverse outcomes can be minimised by programs that aim to increase social skills and attachment to schools (Hawkins et al. 1992). Somewhat like immunisation, 'one shot' programs in children with an accumulation of risk are unlikely to be successful - 'booster' programs at key developmental transitions are beneficial (National Crime Prevention 1999), and many families need ongoing support.

Adolescence is a time when one can look both backwards to the impact of risk and protective factors on current health status and forward to their likely impact in adult life. Whether one follows children and young people prospectively or examines their progress retrospectively, it is clear that risk does not equate to destiny.

Thus, it is important to adopt developmental approaches which do 'not see life as marked by one steady march toward adulthood that is set early in life, or one steady line of change, either for better or for worse' (National Crime Prevention 1999: 8), and to acknowledge that 'what occurs is a series of phases, a series of points of change, a series of transitions. These phases and transition points are where intervention can occur most effectively' (National Crime Prevention 1999: 8).

Adolescence is a particularly important transition point. This is the period in which several behaviours with the potential to have a long-term adverse impact on health (for example, tobacco use) often become established. For too long these behaviours have been viewed as part of the normal turbulence of adolescent development. It has been assumed that adolescents will mature out of health risk behaviours in young adulthood.

It is only in the past two decades that adolescent health risk-behaviours have attracted the attention they deserve. It is now clear that many aspects of health initiated in the teens are carried into adulthood where their persistence contributes ultimately to the burden of disability and mortality. Examples include common mental disorders characterised by depression and anxiety where most recurrent disorders have a first onset before the age of 25 years. Continuities in tobacco use, dietary choice and patterns of physical inactivity also appear very strong, whereas for illicit drug and alcohol use, and sexual risk taking, social transitions in young adulthood appear influential. (Chen and Kandel 1995).

The case for investing in early intervention

A growing body of knowledge is accumulating, predominantly from North American research, of the benefits of early intervention to maximise developmental health and wellbeing (Shonkoff and Meisels 2000; National Crime Prevention 1999; Karoly et al. 1998). There is a small body of Australian data which also demonstrates the impact of a limited range of programs such as home visitation in infancy (Armstrong et al. 1999) or behavioural approaches to enhanced parenting (Williams et al. 1998). Doing nothing is a choice that Keating (1999) argues will lead to the development of a technological and cognitive elite separated from an increasingly marginalised mass population in which the problems of developmental health and wellbeing will be over-represented.

Cost effectiveness of early intervention

Early intervention means intervention early in the pathway, which may or may not mean early in life. A developmental approach is characterised by 'a pervasive emphasis on pathways and on aspects of time and timing. Pathways are roads through life that fork out in different directions at the kinds of crucial transition points that mark new experiences or relationships' (National Crime Prevention 1999: 9).

The concept of multifinality encapsulates the notion that similar risk and protective factors contribute to a range of adverse outcomes. For example, Table 2.1 summarises a range of potentially modifiable social, family and individual developmental risk factors for a range of adverse adolescent outcomes that have ongoing implications for later health education and wellbeing.

similar risk and protective factors contribute to a range of adverse outcomes

A similar table outlining the risk and protective factors in the early years is shown as Table 2.2 (Huffman et al. 2000).

risk and protective factors in the early years

These matrices of associations carry important implications for the development of early intervention strategies whether they have health, social, educational or criminal behaviour outcomes in focus. On this basis, there have been calls for intervention approaches that target important risk determinants that cut across multiple health and wellbeing issues. Broadly based strategies targeting a range of risk and protective factors will benefit a number of outcomes.

This approach is dependent on an understanding of the relationships and risk processes that exist in between the type of determinant shown in Table 1 and the ultimate health, social and educational outcomes. At the current time, that understanding is largely dependent on information from overseas studies that may not be invariably applicable in the Australian context.

What is clear from this research in both children and young people is that the costs of early intervention strategies are frequently far less than the costs of the later management of the problems they are designed to prevent. For example, the Perry Preschool Program, which provided four half-day sessions of structured preschool experience for disadvantaged 3-4-year-old African Americans combined with weekly home visits to their families, returned savings over the subsequent 27 years of more than US$6 for each $1 invested (Weikart and Schweinhart 1992). Similarly, the prenatal and infancy nurse home visitation program in Elmira (New York), which involved regular home visitation from the third trimester of pregnancy until the child's second birthday, also returned savings in the most disadvantaged group of single, poor, teenage first-time mothers of around $6 for every dollar invested over the next 15 years, by achieving better outcomes in both mothers and children (Karoly et al. 1998; Olds et al. 1997).

Costs of maintaining the status quo

To do nothing about ameliorating the impact of the 'great disruption' on the lives of children would ill-equip Australia to play a prominent role in the global community as a knowledge-based economy. Keating and Hertzman (1999: 15) assert that: 'The ability to 'apply labour' with skill and judgement presumes that high levels of health, competence and coping exist in the population so that human resources are available for use in knowledge-based economies that rely on an innovation dynamic. The larger the proportion of the population able to participate productively in such economies the greater the likelihood of increased economic prosperity.'

Keating and Hertzmann (1999: 15) go on to argue that: 'The wealth of nations in the Information Age depends heavily, perhaps primarily, upon their ability to promote the developmental health of their populations.' As in the United States, it is likely that in Australia: 'Striking disparities in what children know and can do are evident well before they enter kindergarten. These differences are strongly associated with social and economic circumstances, and they are predictive of subsequent academic performance. Redressing these disparities is critical, both for the children whose life opportunities are at stake and for a society whose goals demand that children be prepared to begin school, achieve academic success, and ultimately sustain economic independence and engage constructively with others as adult citizens.' (Shonkoff and Phillips 2000: 5)

Universal versus targeted service provision

There is much debate about the proper balance of efforts at improving developmental health and wellbeing outcomes. The universalists and the advocates for targeted solutions both argue their case on the basis of a better return on investment. The universalists point to a gradient in outcomes across the whole socio-economic spectrum and emphasise the sheer size of the middle range of the population who could benefit from interventions known to improve outcomes. They also argue that universal approaches are less stigmatising and are more likely to enlist higher needs families in service provision.

The advocates for targeted solutions point to the limited amount of funding usually available for intervention and the dilution of impact that is likely to ensue if it is spread across the whole population, and the historical evidence of the ability of the middle-class to capture welfare programs that are likely to have particular relevance for higher needs families. They fear that, because of the great difficulty in engaging high needs families compared with those who are more receptive to intervention, resources will never trickle down to those with the greatest need - inequality could actually be worsened. There is also some evidence that while there is a gradient, the magnitude of differences in outcomes experienced at the bottom end of the distribution warrant more attention being given to selective or indicated interventions.

Australia and some other countries, such as the United Kingdom, have tended to reach a compromise position - for example, in urban renewal projects where universal interventions are offered in localities of high need identified on the basis of selected indicators of developmental health and wellbeing. Targeting advocates nevertheless point to the fact that most of the disadvantaged in a country don't live in such areas and miss out on such locality-based interventions, particularly if funding available for spreading across the rest of the community is limited and unlikely to resource the additional efforts required to reach high needs families. In New Zealand and Victoria, maternal and child health nurses are funded to provide additional services to high needs families, but this may have a stigmatising effect for families known to be receiving more than basic services.

Offord and colleagues (1999) provide an excellent summary of the debate concluding that, with respect to the mental health problems, the jury is still out on the best mix of clinical, targeted and universal interventions.

Contemporary Australian understandings

There have been notable attempts to translate the research evidence into policy and practice in Australia. For example, the Stronger Families and Communities Strategy attempts to introduce a range of early intervention strategies into disadvantaged communities across Australia. But our efforts are frequently poorly informed by evidence of program efficacy in our own context. The establishment of a dynamic research partnership between researchers, policy makers and practitioners could begin to address this gap more effectively than at present.

What do we know in Australia?

There is a growing body of cross-sectional data of risk factor prevalence and on developmental health and wellbeing outcomes at a state and national level. These include state (Silva et al. 1999; Zubrick et al. 1995; Vinson 1999) and national reports on the health status of Australian children and young people (Moon et al. 1998, 1999; Sawyer et al. 2000). Western Australia is uniquely placed in having a variety of population registers, such as the Western Australian congenital malformations and cerebral palsy registers (Bower and Stanley 1983; Stanley and Watson 1985).

There has, however, been a dearth of longitudinal studies of developmental health and wellbeing in Australia. Amongst the exceptions are: the Mater study in Brisbane (Najman et al. 1997) which among other things has examined the impact of socio-economic disadvantage on developmental health outcomes; the Raine study in Perth (Silva et al. 1999) which has focused more on physical health outcomes; the Australian Temperament Project (Prior et al. 2000) which investigates pathways to positive and problematic adjustment and the contribution of child, family and environmental factors to successful functioning; and the Port Pirie cohort study (McMichael et al. 1992) that examined the impact of pre- and post-natal lead exposure on child development (see Nicholson et al. in Chapter 3 of this volume for more details).

While Australia has some early intervention programs that are based on home visiting (for example, Vimpani et al. 1996), parent training (for example, Sanders and Markie-Dadds 1996), and ecological intervention for aggressive behaviour and bullying (for example, Rigby 1994), there have been few longitudinal evaluations of their outcomes. They have, however, alerted policymakers to the importance of prevention, and the place of community development projects in providing the necessary supports to families to reduce the level of developmental risk to their children.

What we don't know in Australia

Throughout this chapter, the lack of outcome data on the effectiveness, in the Australian context, of early intervention programs that are based on overseas models, has been stressed repeatedly. The impact on children and young people of broadly-based community and economic interventions is often not addressed; some have called for the development of child impact statements as a way of monitoring the impact of such interventions. Moreover, there is a need for more broadly-based intersectoral research examining the impact of risk and protective factors from a variety of perspectives - for example, by establishing collaborations involving policy-makers, practitioners and academics from multiple disciplinary backgrounds, to examine the impact of issues like nonparental care on developmental health and wellbeing outcomes.

The recent interprofessional literature review by Homel's team for National Crime Prevention (1999) is one helpful paradigm. The experience of the Canadian Institute of Advanced Research Human Development group (Keating and Hertzmann 1999) indicates how much can be gained by deliberate efforts to forge ongoing linkages between what are complementary but often disconnected research traditions.

Shonkoff and Phillips (2000) identify a research agenda that includes: enhanced understanding, detection and treatment of early precursors of psychopathology; improved preventive and ameliorative interventions for women and children who are exposed to biological insults and adverse environmental conditions, as well as for children with identifiable disabilities; the identification of modifiable mechanisms that link impoverished family resources to both adverse outcomes for individual children and persistent disparities across groups of children in learning skills and other developmental capacities; and (of particular relevance in Australia) refined understanding of how interventions and the staff that implement them can work effectively with families that differ along dimensions defined by race and ethnicity, immigration status, religion, or other cultural characteristics.

There are other research needs that we also share with other countries, including the integration of child development research with neuroscience and the emerging field of molecular genetics.

According to Shonkoff and Phillips (2000: 13): 'Enormous potential exists at the intersection of child development research, neuroscience, and molecular and behavioural genetics to unlock some of the enduring mysteries about how biogenetic and environmental factors interact to influence developmental pathways. These include: (a) understanding how experience is incorporated into the developing nervous system and how the boundaries are determined that differentiate deprivation from sufficiency and sufficiency from enrichment; (b) understanding how biological processes, including neurochemical and neuroendocrine factors, interact with environmental influences to affect the development of complex behaviours, including self-regulatory capacities, prosocial or antisocial tendencies, planning and sustained attention, and adaptive responses to stress; (c) describing the dynamics of gene-environment interaction that underlie the development of behaviour and contribute to differential susceptibility to risk and capacity for resilience; and (d) elucidating the mechanisms that underlie non-optimal birth outcomes and developmental disabilities.'

Importance of linking research to policy and practice

'Science is focused on what we do not know. Social policy and the delivery of health and human services are focused on what we should do' (Shonkoff 2000: 182). Scientists are trained to ask questions and to be guided by facts, whereas policymakers are governed by political and economic forces that emanate from society; service providers are more akin to policy makers in needing to 'act' before all the data are in. Shonkoff calls for a commitment to 'cross-cultural' translation among these three groups as a means for reconciling these differences and increasing the use of knowledge to improve the lives of children and families.

A recent volume of Development and Psychopathology was devoted to the social policy implications of developmental psychopathology, and in making a plea for increasing sophistication of research so that it might better inform public policy, its editors (Cicchetti and Toth 2000: 553) argue for courage amongst young investigators to grapple with complex issues and tackle research with policy implications: 'The development of research agendas that address normal and abnormal development across psychological and biological domains throughout the life course is critical if policy is to be formulated in the best interest of society. Such well-designed and well-planned investigations are necessary to avoid unwarranted assumptions and the misuse of research data.'

Cicchetti and Toth (2000: 554) conclude that: 'The 21st century presents us all with a unique opportunity to translate rhetoric into action and to truly achieve a research-informed policy agenda that will benefit the welfare of all.' The authors of this chapter fully endorse this sentiment.

Australia is at a challenging moment in the development of more 'joined up' policies and programs to address contemporary problems of developmental health and wellbeing. It is clear that the 'silos' that have emerged to provide our current mix of services are ill-equipped to provide the integrated sets of programs that children and young people need for optimum development.

Similarly, research is needed that brings together different disciplines that can address the foundations of developmental health and wellbeing and the causal pathways to dysfunction. Furthermore, an integration of quantitative and qualitative methodologies will be needed to help unpick not only what works or doesn't work, but how and why this might be so. A virtuous cycle of growing understanding and improvement would be a welcome outcome.

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