Adaptation of the Steen Happiness Index (SHI) to Brazil: A Comparison of the Psychometric Properties of the SHI and the Subjective Happiness Scale.

This study examined the psychometric properties of the Steen Happiness Index (SHI)-a measure of authentic happiness designed for intervention research-in a sample of Brazilian security workers. The SHI has yet to be used in a Brazilian sample and has the potential to assess both eudaimonic and hedonic happiness in Brazil. The psychometric properties of the SHI were also compared with those of the Subjective Happiness Scale (SHS), a widely used happiness measure, using classical test theory and item response theory. Military police officers, civilian police officers, and military firefighters (N = 435) completed the SHI, SHS, and measures of well-being, optimism, and psychopathological symptoms. Exploratory factor analysis provided support for a one-factor SHI-rather than the three-factor structure found in previous research. The unidimensional SHI also better discriminated between low, medium, and high levels of happiness, and did not demonstrate a ceiling effect when compared with the SHS. Advantages and disadvantages of both scales are discussed.