I think about this one a lot, how easy it is for pattern recognition to misfire and synthesize conclusions and connections that are partially rational and correct, but with one bad piece of input data skewing them into fantasy. Sometimes the conclusion may be right, but its magnitude, impact, or applicability are grossly overestimated. Part of what makes such gifted people is the ability to imagine, hypothesize, and use hypotheticals. This giftedness often coincides with the ability to make many parallel what if thoughts and identify the most probable. At some point, hypotheticals morph into faith and what was once a thought experiment becomes belief. What ifs break down into belief "this is actually happening, this is reality." It becomes its own compounding feedback loop, as faulty conclusions layer on top of each other over time.

His younger brother, my uncle, was diagnosed with schizophrenia at age 20 after becoming severely erratic while away from home on an LDS mission. The diagnosis devastated their family, and has been followed by decades of difficult treatment and heartbreak.

What is it about my uncle that pushed him over the edge? Environment? Genetics? Pure chance? I wish I could know. My dad says that there's not much left of him except for a few moments here and there.

My dad had a big family, and he's said that his younger brother always showed the most promise, growing up. Smart, charming, super friendly. 30 years on he continues to greet everybody with a smile and hug, even if he doesn't know them!

It's sobering to see it in my own family, and it keeps thoughts like the one you articulated so well in the back of my mind constantly.

"The gist, then, is that someone is “himself” because countless mental artifacts stay firm from one day to the next, anchoring that person's character over time."

I have read reports that latent schizophrenia is often revealed when people travel abroad. Maybe if your environment and surroundings change drastically, your mind loses its sense of "self" that was based around anchors to the rest of the environment.

This journal article touches on this:

"Long distance travel has long been known to aggravate pre-existing psychosis.... Travel can be a destabilizing life event7 with many potential hazards to mental health, from the effects of drugs used for prophylaxis against infection, to homesickness, to disrupted circadian rhythms, to culture shock." http://www.ijtmgh.com/article_33029_738f7bb0f6124261891cf610...

Saying this as someone whose mother scored in the top 1% on the SAT and was schizophrenic.

Schizophrenia is different that it is at least partially behavioral. The brain is more like an adaptive neural network, so it's sometimes hard (or impossible) to disentangle hardware from "behavioral configuration". In the case of schizophrenia I think (not a doctor!) there is a (perhaps structural) disposition toward modes of thinking, psychosis, delusion etc. -- thought and behavioral patterns that develop if there is inadequate self-assessment in place (which is how I would explain identical twins differentially developing the condition), and experiences of stress and trauma that can disrupt benign thought.

It is a terrible condition... I have close family members with psychosis too (that's somewhere in the spectrum of bipolar to schizophrenia). For me it appears quite clear why intelligence has a protective effect (and one of the many reasons I value, and cherish, intellectual activities of all kinds so much).

Counter to opinions elsewhere (where you shouldn't live in the "shadow of the disease" through genetic screening, family history, etc.), I personally do think it's important to be mindful of it. That way at least symptoms may be recognized early and treatment can be more effective (since it is at least partially treatable and has a large behavioral aspect). Here's hoping we never develop it.