when nephron development takes place, are most at risk of hypertension (Roseboom et al., 2001; Keller et al., 2003). Outcomes associated with programming early in life may also promote health. For example, rats receiving high levels of licking and grooming as pups are less fearful compared with rats that received low levels of licking and grooming (Francis et al., 2002). The mechanism for this change in behavioral programming appears to be the influence of maternal licking on gene expression during a critical period of development and subsequent changes in the development of synaptic receptor sites for specific neurotransmitters (Francis et al., 1999).
Similar environmental influences on the development of behavioral pathways have been described in rhesus monkeys (Champoux et al., 2002), and studies of premature human infants show substantially greater increases in body weight after introduction of massage therapy (Field, 2002). In contrast, disruption of maternal bonding during infancy has been shown to have profound negative effects on later relationships (National Research Council and Institute of Medicine, 2000).
As used in this report, behavior refers to a child’s emotions, beliefs, cognitions, and attitudes, as well as his or her overt behaviors. Some behaviors are planned and deliberate; others are reflexive, impulsive, and contingent on environmental circumstances. A child’s emotions, beliefs, and attitudes affect health, principally through the way they modify a child’s explicit and overt behaviors, such as his or her health and life-style choices. These in turn alter the child’s eventual health outcomes. Examples include social and interactional behaviors (e.g., compliance with parental requests, peer interactions), health preventive behaviors (e.g., avoiding smoking, driving with a seat belt, choosing good friends), or illness-management-related behaviors (e.g., behavioral adherence with a treatment regimen or health care appointments).
Health-related behaviors may be health promoting (those that increase the likelihood of future health, such as regular balanced diet and exercise) or health impairing (those that adversely cause actual morbidity or mortality, such as smoking, drinking, or reckless driving). A body of recent research suggests how these behaviors develop and describes the role of family, peers, and social environment, including media, in shaping this developmental process (Tinsley, 2003). While behaviors like smoking, drinking, and exercise are known to affect later health, it is not clear how these behaviors develop in childhood (McGinnis and Foege, 1999).
Often these health behaviors are considered proxies for health, even though they may not necessarily constitute health per se. Some health policies attempt to change youth behaviors that are thought to affect health. An example is the re-