Subjects experienced one of three mood-induction procedures (music, vi
deo, or Velten; positive or negative valence) prior to responding to a
recently developed instrument for measuring optimism and pessimism (O
/P). Pre- and post-induction mood indices were also obtained via the M
AACL-R and the Wessman-Ricks elation-depression measure. All three moo
d-induction procedures were effective in establishing the desired mood
s, with the video procedure the weakest. Music and Velten, but not vid
eo, affected optimism and pessimism scores, but for women only. The re
sults suggest, contrary to a previous study, that the optimism/pessimi
sm instrument is not impervious to momentary mood states, at least for
women, thus somewhat reducing its temporal stability. By the same tok
en, however, the results also lend support to the construct validity o
f the O/P instrument.