I suppose that is true, although I've certainly been in a lot more high-stress situations than I've been in life-threatening situations, and I expect that the same goes for most people on this forum. But then again, I don't think that was necessarily the point you were trying to make. I didn't mean to downplay the difficulty of coping high stress situations-- it's legitimately hard. But practice is the best way to increase your likelihood of not-dying.
For example, when I was taking martial arts, I was told that the best thing you can do if you actually want to be able to defend yourself is to drill your basic punches and kicks. The idea being that if you get into an actual fight, you are so comfortable with your moves that you'll be able to execute them, despite the fact that your higher reasoning centers are all going FUCKFUCKFUCKIMUNDERATTACK.
Same principle applies in other areas. You increase your chances of success by training a couple of behaviors or thought patterns until they come so naturally that they will happen even when your brain goes into panic mode.
I think there's a limit to how much a belief like this can be instrumental. It's a belief whose benefit would be very highly context dependent. For example, believing that you are capable of winning a boxing match might be highly instrumental when you're actually in the ring, but it would not be instrumental before the match when you're deciding how much money you want to bet on your performance in the competition (since you would bet as if your likelihood of winning was higher than it actually is).
That said, I think that psychologically dealing with high-stress situations is a skill just like any other. You practice, you fuck up, you think about it, and eventually you get better.
The name is Daniel. I'm 22, coming out of college and running into the problem that there aren't that many people out there who get as excited as I do about epistemology, evolutionary theory, and interdisciplinary science as I do. I ended up coming here because I'm beginning to suspect that the longer I spend not talking about my ideas with other people (see: reality checks), the more likely they are to spiral off into flights of fancy. And nobody wants that. Plus I feel like in the day-to-day life, there's so little opportunity to really engage in productive, mutually satisfying arguments-- you know the sort where you actually feel like you've learned something valuable about the world and the person who you're debating? I miss that, and I hope I can find some of those here.
There are a couple of people I can credit with helping me discover this site. Several of my friends in college introduced me to Eliezer's articles, which I thought were little more than clever. Then, more recently, I discovered Scott Alexander blog, which quickly became my favorite-thing-in-the-world, and got me thinking that maybe I should give this community a second look. And since winter is falling rapidly on the great city where I live, let's face it, I'm not going to want to do much else.
I think if you want to get a sense for where I'm coming from: When I was around 13 or 14, I discovered that myspace (remember when that was a thing?) had debate groups, and since creationism and evolution were hotbutton topics, I decided that I would pitch in to the debates (on the side of atheism and evolution, of course). I can't say I convinced very many creationists to see the error of their ways, but I did learn a lot of cool and interesting things about rhetoric, evolutionary theory, and even theology. I suppose I am coming here with some nostalgia in my eyes.
In college, I studied psychology and the philosophy of science. My interest was in interdisciplinary science, and the people who can walk between scientific disciplines, letting their knowledge of one enrich their understanding of the other. I was interested, more broadly, in how knowledge can be communicated across cultural and boundaries, for it seems that the boundaries are where the most interesting things happen, while also being a place that tolerates the least incorrect thinking.
Right now, I'm working at a market research firm that specializes in the pharmaceutical industry. It's interesting work-- we help pharmaceutical companies understand how doctors evaluate and use new products (spoilers-- doctors are just as irrational as the rest of us). Hopefully my knowledge of medicine and the social science will generally compensate for my horrific ignorance when it comes to computing and mathematics (please don't judge too hard!). But in any case, I look forward to meeting everybody on the forums!
Write things down. I think 90% of successful experimentation is keeping good notes.