That these are just both driven by the same thing. And what you're really seeing here is like, okay, people with high lack of activity who aren't active, well it drives both of these variables. So once again, when you do this observational study, and if you do it well, you can draw correlations, and that might give you decent hypotheses for causality, but this does not show causality. Because you could have these confounding variables. Now experiments, and experiments are the basis of the scientific method. Experiments are all about trying to establish causality. And so what you would do is, if you wanted to do an experiment, you would take, and you probably wouldn't be able to do it with a thousand people, experiments in some way are the hardest to do of all of these.