It seems that many systems currently studied, are very fragile to dechorence. Great care is taken to isolate them from even the smallest amount of interatction with the outside environment. Yet, the most well known quantum mechanics experiment, the double slit experiment, seems incredibly rebust to decoherence. It seems that you can put pretty much anything you like in there aside from actually detecting which slit the particle went through, and the quantum effect remains. Why is this setup so robust and why are other systems so sensitive to decoherence?