conflict managment in growing sprouts

Phil and I debate this often: when should kids just work it out on their own, and when should a parent interfere? "Just before it gets physical and someone loses an eye?" That’s like saying, "Add the fish to the pan, just before the pan starts to smoke." At a certain age, kids understand what it is to take turns, and parents can praise their kids when they see them sharing, but should you really always be the one to elbow in and teach them fairness? Isn’t there something to be said for letting kids work it out on their own? Even if it’s not always fair? Life, after all… well, you know how it goes.