I was just wondering what the theory was behind the use of fiddle toys (or whatever you prefer to call them) during training sessions?

I'm sure I've heard different reasons in the past but I just wanted to read some research on it.

I like using them personally because I come in to contact with a lot of nervous learners and they act as a good ice-breaker and frustration tool.

I also thought there was something in them being sensory and suiting kinesthetic learners?

Can anyone point me in the direction of some research or knows of other reasons why they can help adults learn?

Thank you