Open AccessThe relationship between subjective well-being and mortality within discordant twin pairs from two independent samples.
Author(s) -
Gretchen Saunders,
Irene J. Elkins,
Kaare Christensen,
Matt McGue
Publication year - 2018
Publication title -
psychology and aging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.468
H-Index - 151
eISSN - 1939-1498
pISSN - 0882-7974
DOI - 10.1037/pag0000248
Subject(s) - confounding , demography , twin study , psychology , hazard ratio , monozygotic twin , life satisfaction , affect (linguistics) , longitudinal study , confidence interval , danish , subjective well being , psycinfo , longitudinal sample , developmental psychology , heritability , medicine , medline , biology , genetics , social psychology , linguistics , philosophy , biochemistry , communication , pathology , sociology , psychotherapist , happiness
Prior research has shown robust associations between greater subjective well-being (SWB) and reduced mortality. Whether this observed association is causal in nature or due instead to confounding genetic or environmental factors affecting both SWB and mortality is not well understood. We used a combined sample of 6,802 twins drawn from two cohorts: the Longitudinal Study of Middle-Aged Danish Twins (MADT; N = 2,815, baseline age between 45 and 69 years, M = 56.8, SD = 6.4) and the Longitudinal Study of Aging Danish Twins (LSADT; N = 3,987, baseline age between 70 and 97 years, M = 76.6, SD = 4.9). The relationship between SWB, encompassing measures of life satisfaction and affect, and all-cause mortality was evaluated using survival analyses at both the individual level and within twin pairs. Twin difference analyses were completed within 1,053 monozygotic (MZ) twin pairs and 1,143 dizygotic (DZ) twin pairs to control for genetic and shared environmental confounding. As expected, the individual-level results showed that higher levels of SWB were associated with reduced mortality: affect hazard ratio (HR) = .90, 95% confidence interval (CI) [.87, .94]; life satisfaction HR = .88, 95% CI [.84, .92]. The effect of SWB on reduced mortality remained significant within both MZ and DZ pairs, suggesting that the association is independent of genetic and nonshared environmental confounding factors. These findings, which generalized across both younger (MADT) and older (LSADT) cohorts of adults, remained significant when accounting for demographic factors, physical health, and cognitive functioning. (PsycINFO Database Record