One of the primary catalysts for the developing interest in children's connection to nature has been the rising concern for children's well-being or, more specifically, children's perceived lack of well-being, where lack of connection to nature is seen as a direct contributory factor. The relationship between green space, contact with nature and health has been of growing interest to researchers across several disciplines. Contact with nature contributes to the health and well-being of children in many ways, beginning at birth – physical health cognitive function and self-control, psychological well-being, affiliation and imaginative play and affiliation with other species and the natural world. The environment can severely affect children's health, especially where that environment itself is compromised, by pollution. Natural environments are therapeutic environments and environments that encourage developmental progress, but the most important health benefit of all is that they are environments that nearly always make children happy.