Feng X, et al. – Researchers undertook this investigation to test their hypothesis that more and better quality residential green space would be favorable for well–being and that these links could be subject to effect modification across childhood. They concluded that for promoting child well–being, nearly 21%–40% of residential land–use allocated to green space may be an optimal amount, but with increases in children's age, a parallel increase in the significance of the quality of this green space was noted.