The patterns and distribution of children’s health influences are age specific. A child’s development occurs explosively in the first years of life, gradually becomes slower with advancing age, and again accelerates during adolescence, so that their relative salience varies with age or developmental stage (Bogin, 2001). For example, in young children, family-related influences are a major factor on health and development, with neighborhood, schools, and peer group playing a greater role as individuals age (Nordio, 1978; Rutter et al., 1997; Wadsworth, 1999; Halfon and Hochstein, 2002).
Transitions present special challenges and windows of opportunity. As children move from one stage to another, new demands and stresses may influence their health. At several points (e.g., birth, entry into school, puberty) children must negotiate new environments that challenge adaptive mechanisms in new ways. At the same time, transitions provide an opportunity for growth and mastery and are critical times for interventions (Baltes, 1997; Brazelton, 1995; Graber and Brooks-Gunn, 1996).
There is growing awareness that childhood has a long reach on future health. Several recent reports have emphasized the importance of prenatal and early postnatal development on lifelong health and well-being (Institute of Medicine, 2001b; National Research Council, 2001). For example, birthweight has been shown to be directly related to later cardiovascular disease (Barker, 1998; BenShlomo and Kuh, 2002).
In the committee’s view, another set of changes to the model of children’s health should adequately represent the multiple and interacting influences on health.
At any given time, multiple present and past influences affect children’s current health. Health results from the interaction of genetics and children’s environments. As discussed in Chapter 3, there are many ways in which the environment interacts with and affects the expression of genetic potential, or vice versa. While biological, psychological, behavioral, social, cultural, economic, and physical in-