From the Cover: Childhood self-control forecasts the pace of midlife aging and preparedness for old age

The ability to control one’s own emotions, thoughts, and behaviors in early life predicts a range of positive outcomes in later life, including longevity. Does it also predict how well people age? We studied the association between self-control and midlife aging in a population-representative cohort of children followed from birth to age 45 y, the Dunedin Study. We measured children’s self-control across their first decade of life using a multi-occasion/multi-informant strategy. We measured their pace of aging and aging preparedness in midlife using measures derived from biological and physiological assessments, structural brain-imaging scans, observer ratings, self-reports, informant reports, and administrative records. As adults, children with better self-control aged more slowly in their bodies and showed fewer signs of aging in their brains. By midlife, these children were also better equipped to manage a range of later-life health, financial, and social demands. Associations with children’s self-control could be separated from their social class origins and intelligence, indicating that self-control might be an active ingredient in healthy aging. Children also shifted naturally in their level of self-control across adult life, suggesting the possibility that self-control may be a malleable target for intervention. Furthermore, individuals’ self-control in adulthood was associated with their aging outcomes after accounting for their self-control in childhood, indicating that midlife might offer another window of opportunity to promote healthy aging.

The ability to control one’s own emotions, thoughts, and behaviors in early life sets the stage for many positive outcomes in later life. These include educational attainment, career success, healthy lifestyles (1–4), and, in particular, longevity (5–8). Prospective studies of children, adolescents, and adults have shown that individuals with better self-control—often measured as higher conscientiousness or lower impulsivity—live longer lives (5–8). But, do they also exhibit better midlife aging? Answering this question could reveal opportunities to extend not only life span (how long we live) but also health span [how long we live free of disease and disability (9)]. Here, we used data collected across five decades to connect children’s self-control to their pace of aging in midlife. We also linked children’s self-control with their midlife aging preparedness: the health, financial, and social reserves that may help prepare individuals for longer life span and better health span.Midlife represents a useful window during which to measure individual differences in aging and their relation to childhood self-control. Meaningful variation between individuals in the speed of both physiological and cognitive aging can be detected already at this life stage (10, 11), and prior work has established that individual differences in midlife health are linked to early-life factors (12–14). Furthermore, midlife is a critical period for preparing for the demands of older age (15). Now past their healthy young adult years, individuals must devote greater attention to preventing age-related diseases, increasing their financial reserves for retirement, and building the social networks that will provide practical and emotional supports in old age. Signs of one’s own aging emerge at this life stage, reminding us that multiple health, financial, and social demands are approaching: menopause and presbyopia set in, we start paying attention to our savings accounts, and we see our own futures in our parents’ decline.If outcomes of self-control extend as far as midlife, then it could be a key intervention target. It would also suggest the hypothesis that there may be opportunities to build aging preparedness while individuals are still in their robust forties (15, 16). Much emphasis has been placed on the importance of intervening early in development, and there is vigorous debate over the optimal timing for implementing early-years programs (17–19). Midlife, however, remains a largely unexplored potential window of opportunity for self-control intervention.We tested associations between childhood self-control and midlife aging using data from the Dunedin Longitudinal Study, a prospective study of a complete birth cohort of 1,037 individuals followed from birth to age 45 with 94% retention. As previously reported in this journal, we measured study members’ self-control across their first decade of life using a multi-occasion/multi-informant strategy (2, 20). We measured their pace of aging as well as their aging preparedness in midlife using a range of prespecified measures known to be associated with life span and/or health span (Fig. 1 and SI Appendix, Table S1), which were derived from biological and physiological assessments, structural brain-imaging scans, observer ratings, self-reports, informant reports, and administrative records. We used these data to test two hypotheses. First, we tested the hypothesis that individuals with better self-control in childhood exhibit slower aging of the body and fewer signs of brain aging in midlife. Second, we tested the hypothesis that individuals with better self-control in childhood exhibit better preparedness for the health, financial, and social demands that emerge in later life. Research has shown that self-control predicts health behaviors such as diet, smoking, alcohol consumption, and exercise (4, 21–24). Here, we extend the reach of this research by testing whether self-control predicts outcomes beyond health behaviors, including individuals’ practical health knowledge, their attitudes toward and expectancies about aging, their practical financial knowledge and financial behavior, their social integration, and their satisfaction with life.Open in a separate windowFig. 1.Aging domains and measures assessed in the current study. Column three indicates reference numbers for prior studies documenting associations between the given measure and life span and/or health span. The complete reference list is included in SI Appendix, Table S1.Children’s self-control is correlated with their socioeconomic circumstances (25, 26) and their intelligence (27, 28). Both social class and intelligence have been implicated in life span and health span (29, 30); in fact, both social class and intelligence have been called “fundamental causes” of later-life health (31–33). Social class has been proposed as a fundamental cause because it influences multiple disease outcomes through multiple mechanisms, it embodies access to important resources, and its associations with health outcomes are maintained even when intervening mechanisms change (31). Intelligence has been conceptualized as a fundamental cause for similar reasons (32). For childhood self-control to be implicated as an active ingredient in healthy aging, it is important to show that its effects are independent of these two fundamental influences on children’s futures. We therefore tested whether associations between self-control and aging survived after accounting for children’s social class and intelligence quotient (IQ) [assessing each, like self-control, using repeated measurements across childhood (Methods)].