A study of 320 8-12-year-old children by researchers at the University of British Columbia in Canada looked into the links between spirituality (defined as an inner belief system that a person relies on for strength and comfort), religious practice, temperament and happiness. The study found that those children who said they were more spiritual were happier. Feeling a sense of meaning and value about one's life and the quality and depth of interpersonal relationships were strong predictors of happiness. However, religious practices, such as attending church, praying and meditating had little effect. Temperament was also an important predictor of happiness with happier children being more sociable and less shy.
You can find out more about this research by clicking on the link in the title of this post.