Initially, participants will complete a demographics form and two screening assessments. Then for 14 days, they will be asked to rate their momentary mood and overall pain levels three times per day (shortly after waking up, around 3:00 p.m., and at about an hour before bedtime). At the same time, they will be asked to log each instance of laughter as it occurs, daily, for 14 days. They will carry the log with them throughout each day in order to document each instance of laughter.