The study, published in the peer-reviewed Journal of Happiness Studies, found that spirituality, or an inner belief system that a person relies on for strength and comfort, explained up to 27 percent of the differences in happiness levels among children ages 8 to 12.

By contrast, institutional religious rituals, practices and beliefs -- including attending church, praying and meditating -- produce nearly no change in children's happiness, the University of British Columbia study found.

Factors such as gender or money also contribute very little to happiness, lead study author and psychology Associate Professor Mark Holder said.

The researchers asked 320 children, from four public schools and two faith-based schools, to complete six different questionnaires to rate their happiness, their spirituality, their religiousness and their temperament.

Parents were also asked to rate their children's happiness and temperament.

The authors found that children who said their lives had meaning and value and who had deep, quality relationships -- both measures of spirituality -- were happier than those who didn't.

The authors suggest that strategies aimed at increasing personal meaning in children -- from encouraging altruism and volunteering to asking kids for three things they're thankful for rather than "this is what I did today" -- may increase their happiness.

The study is one of the few seeking to understand children's happiness.