Inducing positive mood without demand characteristics.

The possibility that a state of private self-awareness induced by a small mirror can facilitate the effect of procedures which induce a positive mood was investigated. Participants were 171 female and 60 male undergraduates who were randomly assigned to one of six conditions in a 2 (Mirror vs No-mirror) x 3 (Control vs Velten manipulation vs Music manipulation) design. As predicted, participants who experienced the Velten and Music manipulations in the presence of the mirror reported elevated mood relative to control participants. The mood of participants who experienced the Velten and Music manipulations without the mirror did not differ from the mood of control participants. The potential benefits of using a small mirror as a substitute for explicit instructions about the expected effect of mood-induction procedures are discussed.