Research on dispositional optimism as assessed by the Life Orientation Test (Scheier
& Carver, 1985) has been challenged on the grounds that effects attributed to optimism
are indistinguishable from those of unmeasured third variables, most notably, neuroticism.
Data from 4,309 subjects show that associations between optimism and both depression
and aspects of coping remain significant even when the effects of neuroticism, as
well as the effects of trait anxiety, self-mastery, and self-esteem, are statistically
controlled. Thus, the Life Orientation Test does appear to possess adequate predictive
and discriminant validity. Examination of the scale on somewhat different grounds,
however, does suggest that future applications can benefit from its revision. Thus,
we also describe a minor modification to the Life Orientation Test, along with data
bearing on the revised scale's psychometric properties.