Happiness, or subjective well-being, was measured in a sample of several thousand middle-aged twins using the Well-Being (WB) scale of the Multidimensional Personality Questionnaire (MPQ). The study found that socioeconomic status, education, family income, marital status, and religious commitment accounted for less than 3% of the variance in WB. However, genetic variation explained 44-52% of the variance. The heritability of the stable component of WB was estimated to be around 80%. The study also found that people adapt quickly to changes in life circumstances, and that happiness is not significantly influenced by external factors such as education, income, or marital status. Instead, individual differences in happiness appear to be determined by a stable set point, influenced by personal relationships, religious faith, and the "flow" of work. The study used the Minnesota Twin Registry to examine these factors, finding that women were at least as happy as men. The WB scale was found to be a reliable and valid measure of well-being, with high retest reliability. The study also found that traditional values were only weakly correlated with WB, suggesting that individual differences in religiousness do not account for much of the variance in happiness. The study also examined the heritability of happiness, finding that genetic factors play a significant role in determining stable components of well-being. The heritability of the stable component of happiness was estimated to be around 80%, with environmental factors accounting for the remaining 20%. The study concluded that individual differences in happiness are primarily a matter of chance, with genetic factors playing a significant role in determining stable components of well-being. The findings suggest that happiness is a stochastic phenomenon, influenced by both genetic and environmental factors.Happiness, or subjective well-being, was measured in a sample of several thousand middle-aged twins using the Well-Being (WB) scale of the Multidimensional Personality Questionnaire (MPQ). The study found that socioeconomic status, education, family income, marital status, and religious commitment accounted for less than 3% of the variance in WB. However, genetic variation explained 44-52% of the variance. The heritability of the stable component of WB was estimated to be around 80%. The study also found that people adapt quickly to changes in life circumstances, and that happiness is not significantly influenced by external factors such as education, income, or marital status. Instead, individual differences in happiness appear to be determined by a stable set point, influenced by personal relationships, religious faith, and the "flow" of work. The study used the Minnesota Twin Registry to examine these factors, finding that women were at least as happy as men. The WB scale was found to be a reliable and valid measure of well-being, with high retest reliability. The study also found that traditional values were only weakly correlated with WB, suggesting that individual differences in religiousness do not account for much of the variance in happiness. The study also examined the heritability of happiness, finding that genetic factors play a significant role in determining stable components of well-being. The heritability of the stable component of happiness was estimated to be around 80%, with environmental factors accounting for the remaining 20%. The study concluded that individual differences in happiness are primarily a matter of chance, with genetic factors playing a significant role in determining stable components of well-being. The findings suggest that happiness is a stochastic phenomenon, influenced by both genetic and environmental factors.