Descriptive and Bivariate Relations
Descriptive statistics are given in Table 1. In addition, the last column indicates the Pearson r correlations between each variable and career success. Childhood factors, including intelligence, childhood conscientiousness, motivation, and ambition, were related to more successful careers. Specifically, success was positively correlated with: (1) childhood conscientiousness, r(691) = 0.09, p = 0.02; (2) childhood motivation, as rated by parents and teachers, r(691) = 0.12, p = 0.001; (3) ambition, rated retrospectively by parents in 1940, r(348) = 0.17, p = 0.002; and (4) ambition, rated retrospectively by the participants in 1960, r(493) = 0.15, p = 0.0006. In addition, objective career success was related to better midlife mental adjustment (r(635) = 0.13, p = 0.002) and to an older age at death (r(630) = 0.13, p = 0.001).
We next examined the relation of midlife career success to mortality risk, with the potential moderating effects of personality, through a series of Cox proportional regression survival analyses. In each case, we present the relative hazards (rh) and 95% confidence intervals (CI).
First, as predicted, career success was related to lower mortality risk (rh(691) = 0.80 [CI = 0.71, 0.91]). Men who were independently rated by Terman as most successful in 1940 were less likely to die at any given age than those who were rated as least successful. Figure 1 illustrates the relation between career success and mortality risk by plotting a cumulative hazard function for each group.
Second, we examined whether intelligence and personality were related to longer life. As previously found with this sample, childhood conscientiousness was significantly related to lower mortality risk (rh(691) = 0.82 [CI = 0.74, 0.91]). Motivation and intelligence were not significant predictors of mortality risk (rhmotivation = 1.01 [CI = 0.91, 1.12]; rhiq = 1.00 [CI = 1.00, 1.01]).
Third, we examined the degree of overlapping variance predicted by career success and conscientiousness by simultaneously including the two. This model estimates the unique effect of career success on longevity after controlling for conscientiousness and the unique effect of conscientiousness after controlling for career success. As demonstrated in the top section of Table 2, both variables remained strong, significant predictors of mortality risk (rhcareer success = 0.80 [CI = 0.71, 0.90]; rhconscientiousness = 0.82 [CI = 0.74, 0.91]), indicating that although the two are related, conscientiousness and career success are independently relevant to longevity. Childhood motivation and intelligence remained non-significant predictors and did not alter the success–longevity relation.
Fourth, we examined whether personality moderated the career–longevity link by including interaction terms between career success and the childhood conscientiousness, motivation, and IQ variables. As shown in the middle section of Table 2, the interactions between career success and both childhood conscientiousness and motivation were significant predictors of mortality risk (rhconscientiousness = 1.03 [CI = 1.00, 1.05]; rhmotivation = 1.03, [CI = 1.00, 1.05]). Figure 2 graphically displays the mortality risk for an individual at the first, second, and third quartiles (on the personality variables) for each group (most successful, moderately successful, and least successful). As can be seen in the first graph, conscientiousness was most important, in terms of mortality risk, for those in the least successful group. Although the least successful individuals were at the highest mortality risk, this risk was moderated by their level of conscientiousness, with high conscientiousness attenuating the risk associated with low success. Further analyses (scatterplots not shown) suggest that those who were both unconscientious and unsuccessful were especially likely to die before age 60. Similarly, for individuals with low childhood motivation, unsuccessful individuals were at a much greater mortality risk than very and moderately successful individuals.
It is possible that the relations between career success and longevity, and the moderating effects of personality, simply extend from health and adjustment (i.e., the healthy are more successful and live longer). To examine this possibility, we examined the relation of midlife physical health, mental adjustment, and alcohol use on mortality risk, and then included these with the other significant variables (career success, conscientiousness, motivation, and the interaction terms). Individually, self-reported physical health and mental adjustment were marginally related to decreased mortality risk (N = 637; rhhealth = 0.91 [CI = 0.80, 1.03]; rhadjustment = 0.94 [CI = 0.82, 1.08]). Alcohol use was related to increased mortality risk (rhalcohol = 1.23 [CI = 1.11, 1.36]). As shown in the bottom section of Table 2, career success, conscientiousness, and the interactions remained significant after controlling for these health-related factors.
Prior studies with the Terman sample found that unstable marital history, alcohol use, smoking, and poor mental health predicted increased mortality risk [35, 51, 52]. In a supplemental analysis, we examined these variables as potential mediators that might explain the main effects and interactions. Confirming results from our prior studies, now predicting mortality risk through 2006, experiencing divorce, alcohol use, or being a smoker predicted increased mortality risk (rh(620)divorce = 1.30, [CI = 1.07, 1.58]; rh(638)alcohol = 1.24 [CI = 1.12, 1.37]; rh(356)smoking = 1.31 [CI = 1.11, 1.55]). Higher conscientiousness or more success was related to more stable marriages and less smoking and drinking. Including these predictors in the model with conscientiousness, career success, and the interactions slightly reduced the effect of career success on mortality, but did not alter the effects of conscientiousness or the interactions.