Well let me start this off by saying this, I love fidget toys they are very fun to play with when you have nothing to do, but making the broad assumption saying they help kids focus is incorrect, if you ever play with a fidget toy not just spinners, instead of using them and focusing on whatever it is you need to focus on, you focus on the spinner toy, it's like clicking your pen , except with a spinner , kids are always trying to do tricks and try new things with it , which is directing their focus towards the spinner and not the subject they are supposed to be focusing on. And you might be saying oh "he doesn't know that". So I got a fidget spinner for myself, and I noticed that while playing with it, I was completely zoning out to whatever the subject I was supposed to be focused on. This may not be with everyone, but it's more like splitting our focus giving 50% to the spinner and 50% to whatever you are supposed to be doing.