摘要：Objectives. We sought to investigate the structure of the genetic and environmental influences on 3 measures of mental well-being. Methods. Analyses focused on the subsample of 349 monozygotic and 321 dizygotic same-sex twin pairs from a nationally representative sample of twins who completed self-report measures of emotional, psychological, and social well-being. Results. The best-fit model contained a common pathway to all 3 measures of well-being, no shared environmental effects, and 1 set of parameters for men and women. Heritability for the latent “mental well-being” factor was high (72%) and best indexed by psychological well-being. Moderate trait-specific genetic effects were seen for emotional and social well-being. Nonshared environmental effects for all measures were mostly trait specific. Conclusions. Genetic influences on the measures of mental well-being reflect a single, highly heritable genetic factor, although some trait-specific genetic influences were seen for emotional and social well-being. Moderate proportions of environmental influences were also shared, but the majority of unique environment was trait-specific. Historically, mental health has been viewed as the absence of mental disorder, despite concepts that health in general is something positive 1 or well-being, 2 and not merely the absence of illness. Mental well-being (i.e., positive mental health) is now a focus of policy and science. The 1999 US Surgeon General's report was devoted to mental health, defined as “a state of successful performance of mental function, resulting in productive activities, fulfilling relationships with people, and the ability to adapt to change and to cope with adversity.” 3 (p4) In 2004, the World Health Organization highlighted the need to promote good mental health, defined as a state of well-being in which the individual realizes his or her own abilities, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to his or her community. 2 (p12) Mental health has been operationalized under the rubric of subjective well-being, or individuals’ evaluations of the quality of their lives. The nature of subjective well-being has been divided into 2 streams of research. The first of these streams equates well-being with happiness or feeling good. The second approach to well-being focuses on human potential that, when cultivated, results in functioning well in life. These 2 streams of subjective well-being research grew from 2 distinct philosophical viewpoints on happiness—1 reflecting the hedonic tradition, which championed positive emotions, and the other reflecting eudaemonic tradition, which championed striving toward excellence in functioning as an individual and a citizen. The hedonic tradition is reflected in research on emotional well-being, where scholars use measures of satisfaction with life and positive affect (e.g., cheerfulness, happiness, and contentment). 4 The tradition of eudaemonia is reflected in research on psychological 5 and social 6 well-being. Here, scholars use multidimensional scales that ask individuals to evaluate how well they see themselves functioning in life as they strive to achieve secular standards of purpose, contribution, integration, autonomy, intimacy, acceptance, and mastery in life. When subjective well-being is measured comprehensively, studies support the tripartite model consisting of emotional, psychological, and social well-being among US adults, 7 college students, 8 and adolescents. 9 Existing literature on the genetic and environmental etiology of subjective well-being has focused on the emotional well-being components of satisfaction with life, 10 positive affect, 11 – 15 or both aspects, with evidence suggesting that a common set of genes underlies both life satisfaction and positive affect. 16 Broad heritability estimates in those studies have ranged from 36% to 56%; no study has found evidence for strong effects of the family environment. Only 1 study 14 found support for sex-specific effects, with females reporting a slightly (8%) higher heritability estimate than that reported by males. Our purpose was to extend previous studies by investigating the genetic and environmental influences on the 3 components of subjective well-being that comprise the assessment of the mental health continuum. 17 We also examined whether the structures of the genetic and environmental influences on the components of mental well-being are the same for men and women. We conclude by discussing the public health implications of the heritability of mental well-being, or positive mental health, for prevention of mental illness.
