Life course work on stress, allostatic load, and the aging process explains how social factors coalesce to produce cumulative health advantages or disadvantages throughout life (Berkman et al. 2000, Seeman et al. 2002). Allostatic load refers to “a cumulative measure of physiologic dysregulation across multiple systems” (e.g., increased blood pressure), proposed to have “considerable impact on future health risks” (Karlamangla et al. 2002, p. 696). Stress increases allostatic load, and, in turn, the “weathering” of systems diminishes health (Geronimus et al. 2006, McEwen & Stellar 1993). Unhealthy behaviors add significantly to allostatic load (McEwen & Stellar 1993). Social ties may foster healthy or unhealthy habits throughout life, either alleviating or contributing to allostatic load and the biological weathering that results. Social ties and health habits may then work together to affect the pace of aging and premature mortality. This process begins early with potentially cascading effects throughout life. For example, cigarette use—often viewed as a stress relief tool—is more common among teenagers experiencing social stress, such as those experiencing problems with parents or at school (Johnson & Hoffman 2000, Kirby
