A lot of rationalists that go deep are on the autistic spectrum. Their feedback loops are often classic autistic thought traps of people who end up "committing to the bit". Add anxiety to it and you get autistic style rumination loops that go nuts.
Edit: Funny enough, when I wrote "autistic thought traps", I thought I just made it up to describe something, but it is common terminology. An AI summary of what they are:
Autistic people may experience thought traps, which are unhelpful patterns of thinking that can lead to anxiety and stress. These traps can include catastrophizing, all-or-nothing thinking, and perseverative cognition.
Catastrophizing:
Jumping to the worst-case scenario;
Imagining unlikely or improbable scenarios;
Focusing on negative aspects of a situation;
Having difficulty letting go of negative thoughts;
All-or-nothing thinking:
Categorizing people or things as entirely good or bad;
Having a tendency to think in black and white;
A lot of people say this, but I think it's the wrong word in an important way.
I'll give you P(autistic|rationalist) > P(autistic), but beware the base rate fallacy. My guess is you're focussing on a proxy variable.
To show some important counter-examples: Temple Grandin, famously autistic and a lot of people's idea what autism means - not a rationalist in the sense you mean. Scott Alexander - fairly central example of the rationalist community, but not autistic (he's a psychiatrist so I trust him on that).
EDIT: also P(trans|rationalist) > P(trans), but P(rationalist|trans) I'd say is fairly small. Base rate fallacy and something something Bayes. Identifying these two groups would definitely be a mistake.
I think when you look at these types of groups that become cult or cult-like, they often appeal to a specific experience or need that people have. My guess is the message that many trans and autistic people take away is fulfilling for them. Many people in these communities share similar traumas and challenges that affect them deeply. It makes them vulnerable to manipulation and becoming true believers capable of more extreme behavior.
The more common pattern is a false prophet cult where the influential leader is a paternal figure bringing enlightenment to the flock. It just so happens that free labor and sex with pretty girls are key aspects of that journey.
It doesn't mean that "all X are Y" or "Y's are usually X".
Edit: Funny enough, when I wrote "autistic thought traps", I thought I just made it up to describe something, but it is common terminology. An AI summary of what they are:
Autistic people may experience thought traps, which are unhelpful patterns of thinking that can lead to anxiety and stress. These traps can include catastrophizing, all-or-nothing thinking, and perseverative cognition.
Catastrophizing: Jumping to the worst-case scenario; Imagining unlikely or improbable scenarios; Focusing on negative aspects of a situation; Having difficulty letting go of negative thoughts;
All-or-nothing thinking: Categorizing people or things as entirely good or bad; Having a tendency to think in black and white;