Causes of individual differences in adolescent optimism: a study in Dutch twins and their siblings

Abstract

The aim of this study was to investigate the degree to which genetic and environmental influences affect variation in adolescent optimism. Optimism (3 items and 6 items approach) and pessimism were assessed by the Life Orientation Test-Revised (LOT-R) in 5,187 adolescent twins and 999 of their non-twin siblings from the Netherlands Twin Register (NTR). Males reported significantly higher optimism scores than females, while females score higher on pessimism. Genetic structural equation modeling revealed that about one-third of the variance in optimism and pessimism was due to additive genetic effects, with the remaining variance being explained by non-shared environmental effects. A bivariate correlated factor model revealed two dimensions with a genetic correlation of −.57 (CI −.67, −.47), while the non-shared environmental correlation was estimated to be −.21 (CI −.25, −.16). Neither an effect of shared environment, non-additive genetic influences, nor quantitative sex differences was found for both dimensions. This result indicates that individual differences in adolescent optimism are mainly accounted for by non-shared environmental factors. These environmental factors do not contribute to the similarity of family members, but to differences between them. Familial resemblance in optimism and pessimism assessed in adolescents is fully accounted for by genetic overlap between family members.

Common mental disorders and subjective well-being: Emotional training among medical students based on positive psychology

“…An article on the genetics of optimism was made available for study between the weeks that had debates and the third meeting [71]. The third meeting began by briefly summarizing the main points of the second meeting and debating the scientific article that was made available.…”

Genetic Influences on the Covariance and Genetic Correlations in a Bivariate Twin Model: An Application to Well-Being

“…Participants had to rate their agreement with the items on a 5-point Likert scale (1 = strongly disagree , 5 = strongly agree ). As Mavioğlu et al ( 2015 ) concluded that the LOT-R should be considered a bi-dimensional scale with two correlated constructs of optimism and pessimism, we summed the scores on the three optimism items to create an optimism score instead of using all six optimism and (reverse coded) pessimism items. An example item is “ In uncertain times, I usually expect the best ”.…”

“…the correlations with life satisfaction (N = 19,831), quality of life (N = 2824) and happiness (N = 5470) were 0.55, 0.53, and 0.36 respectively (Alarcon et al 2013 ). Furthermore, like well-being, individual differences in optimism have been found to be accounted for by genetic influences (around 30%) and non-shared environmental influences (Plomin et al 1992 ; Caprara et al 2009 ; Yuh et al 2010 ; Mosing et al 2010 ; Bates 2015 ; Mavioğlu et al 2015 ).Therefore, we expect a genetic contribution to the strong correlation between well-being and optimism and an overlap in the genetic and environmental factors underlying both traits, resulting in strong genetic and environmental correlations.…”

Genetic and Environmental Contributions to Positive Affect: Insights from Adolescent Twins

“…Presently, most research on positive affect has focused on broad constructs such as "well-being" or "positive emotionality," though a few studies have focused on particular traits. One study of the genetic architecture of trait optimism in adolescent twins revealed heritability estimates between 29 and 38% for the subscale and full scale, respectively (Mavioglu et al, 2015). The results of an investigation of subjective happiness among adolescent twins (mean age of 16) revealed heritability estimate of 34% (Haworth et al, 2017).…”