According to a new study on pre-teen children, higher levels of spirituality correlate with higher levels of happiness. This link is already well established in adults and teenagers. Interestingly, religious practice has little to no effect on a child's happiness.
I would take exception with the study's metrics of spirituality: a sense of meaning and value in one's life and the development of quality relationships. These factors seem quite lacking, don't they? A sense of a transcendent power, perhaps?