The cows produce a lot of milk, the farmers like them more and they wanna name them. It's like, hey, that's my high milk producing cow. So there's a lot of temptation to say naming, that maybe there's a causality that naming causes more milk, more milk, or that maybe more milk causes naming. You or the farmers really like that cow so they start naming them or whatever it might be. But you can't make this causal relationship based on this observational study. You might have been able to do it with a well-constructed experiment but not with an observational study. And that's because there could be some confounding variable that is driving both of them.