• The effects of volitional laughter on positive and negative affect and depressive symptoms

      Krauss, Gregory W. (1997-05)
      The effects of volitional laughter on positive affect, negative affect, and day-to-day depressive symptoms among college students were investigated utilizing a non-equivalent control group design. The laughter group (n = 23) participated in daily volitional laughter treatments (three treatments of 30 seconds each) while the control group (n = 40) received no treatment. Both groups were pre- and post-tested using the PANAS (Positive And Negative Affect Schedule) and the CES-D (Center for Epidemiological Studies -Depression Inventory). A significant difference was found for the laughter group in negative affect. An additional post-hoc analysis, after eliminating a group of subjects from the control group, indicated a significant difference for the volitional laughter treatment group in increasing positive affect. No significant difference in depressive symptoms was detected.