Looping thinking - why and what?

Thanks for your reply. Yes I think my analysis is aimed at neutralising the anxiety as an internal compulsion. 

I think you're right though. The need for certainty Is probably fuelling this which are both recognisable traits in generalised anxiety and ocd.

Most of the time, I'd suggest it's not a symptom of anything if you're autistic. It's a normal autistic response which can become an obsession when one doesn't have the educated reasoning and maturity to appropriately resolve and/or can cause anxiety if it's beyond our control and we fail to respond in an appropriate way which controls what elements we can (depending on the situation). An example here is when someone continues to try and reason with an abusive partner while there's years of nothing changing. In most cases anxiety is simply cured by exiting the situation - it's extra painful at first but after a week one will find they can breathe again better than they had in years. However, personal work on the self and finding perspective of the other are the types of growth needed so one doesn't become obsessive about past 'crimes' or abuses including acknowledging forgiveness (which is really complex and doesn't require one to ever trust the other, just live with not being 'paid back' for whatever they aren't sorry for).

Autistic thinking tends to be driven by analytical reasoning whether or not you have the fundamental skills to do it correctly. This is one thing I want to see changed in education with Autistic children. I've had discussions with other researchers who can also see the  "difference in design" - a drive that is a game-changer and what makes us "Divergent" as we might be driven to find resolve at any cost. Where Neurotypical thinking can be driven to socially dominate at any cost. This drive affects Motive and Intent, which often constitutes misunderstanding and the Dbl Empathy Problem. 

Non-autistic thinking includes creating symbolism and misdirecting an issue. There's little drive to get to the bottom of it, so if there's a subconscious issue and perhaps a wrong done, it can become rumination, which can then also be 'over-coded' apparently and repressed. 

As mentioned here, the bottom up processing (noted by Jung in self-reflective thinkers), coupled with the hyper-focus of montropic brain, create an intense impact, as we tend to 'feel' a more pronounced impact. Sometimes talking about the problem itself to others might help expand beyond your own limit and help produce missing gaps in understanding the fundamental of the problem. I don't mind having a less than agreeable outcome, so long as I have SOMEthing to identify which I can then navigate. 

I have my own way of understanding looping thoughts within autism, whether these are right or wrong, I don't know. I also don't know about OCD  but understand that the thought usually has an action alongside it to mitigate the anxiety the thought causes. I see rumination within autism arising through a strong need for certainty, a need for things to be right/correct/authentic, bottom up processing (detail first to form a bigger picture second),  the notion of monotropic brain (focus on one thing at once) and finally inertia (thoughts or states stay in their current form unless acted on by an outside influence). 

Like I said these are my own theories but help me understand. I think it's in our nature to want to understand things.

Christ, Sam, you're irreplaceable. It's really great to see you around, and not only because you help people (though it's much appreciated).

This can easily be a symptom of both and is one of the OCD and ASC overlaps because people with ASC frequently experience anxiety which is a key emotional component in OCD. If you don't experience any other qualifiers for OCD though it is probably just anxiety which feels magnified by the ASC.