SunAngel, yes I believe the longer hours of sunlight trigger more serotonin release and/ or production in the brain, which makes us feel more energized & happier, etc. I believe it's along the same lines of the concept of how light therapy helps people with seasonal affective disorder. Its supposed to help people who are in a depressive state (in winter months especially) & in the same way, sunlight & longer days in the summer can trigger mania in those who are susceptible