I suspect some self-help fads actually do work when preached by the charismatic individual who started them: e.g., Rev. Norman Vincent Peale preached the Power of Positive Thinking to 9-year-old Donald Trump. But they usually don't replicate well in hands of non-superstars.
How many self-improvement fads/cults continue to work?
Here's an example from sports: serious weightlifting was considered a weird fringe training technique in many sports when I was a kid: e.g., pitcher Nolan Ryan started lifting after the 1972 season, but it took him a half dozen years to find a teammate, Brian Downing, who would do it with him.
Ryan went on to throw his seventh no-hitter in 1991 at age 44. Sandy Koufax is in second all-time with four no hitters. (Downing went on to transform himself into a Clark Kent-lookalike slugger and have a much better career from age 28 through 41 than he had had in his youthful prime.)
So, weightlifting works. (It especially works when combined with Performance Enhancing Drugs, of course.)
Baseball players should have figured out that weightlifting works a long time earlier. The great shortstop Honus Wagner worked out with dumbbells in the offseason 120 years ago. He peaked at age 34 in 1908, about 7 years after most ballplayers.
After his shameful 1925 season, Babe Ruth hired a personal trainer for the off-seasons and tossed the medicine ball around with him, hitting 60 homers in 1927.
So the gold standard of a formerly weird self-improvement cult that now consistently works is weightlifting in training athletes. It never goes out of fashion.
Motivational techniques, in contrast, seem to cycle in and out of fashion, suggesting, what, a placebo effect?
What else might consistently work?
Maybe Stanislavski's Method Acting? Daniel Day-Lewis took it to hilarious new extremes — when playing an 18th Century backwoodsman, he wore deerskins and carried a musket for months — but it sure worked for him.
One technique I recall from Dale Carnegie that seems to consistently work is an idea he borrowed from Ben Franklin: to get people to like you, it's useful to do them a favor, but what really works is to get them to do you a favor.
Fraternities train their bros to walk up to people to say hello, say their own name, and repeat the other person's name while shaking their hand, then reuse the other person's name in the conversation, so that they remember it.
That works.
I hope Cognitive Behavioral Therapy works. It seems pretty reasonable. It's likely that Obama got CBT when he got depressed after his primary defeat in 2000, and, if he did, it worked for him.
There are probably a lot of good ideas that are now considered common-sense that would have seemed weird a few thousand years ago. E.g., as Julian Jaynes pointed out, Odysseus seems more relatable to us moderns than does Achilles.
In American Ninja Warrior the participants one after the other run, jump and climb through a very tough obstacle course, and few reach the finish line. Many fall down in the water below. The commentators note that often participants get stuck on an obstacle, but once one of them get past it it's much more likely that those after him will get past it as well. So your mindset does have an effect.
This can be exaggerated, of course. In blogs based on helping guys hit on girls, which were more common about ten years ago, there were many useful tips. (A small percent of guys raise the sex-partner-average for all guys, making the average far higher than the mean, because about 80 percent of women want them. So don't think the advice blogs tricked young women into having sex. They were already having sex, just with the same guys. Spreading it around a little isn't bad.) But a real bad tip was "fake it til you make it." The idea that it's all about having courage, nothing else needed.
The blog Chateau Heartiste unfortunately went all-out on that one, because it was what so many regular visitors (and why were they regular visitors instead of getting girlfriends?) wanted to hear: It sounded easy. You don't need to work out, don't need money, don't need friends to go out with. Just act like you're great. He even said, "women don't like millionaires because of their money, but because of the CONFIDENCE it gives them." What a sad turn in that blog. The truth is, "fake it til you make it" would make some guys go out and be loud, with big smiles plastered on, and they'd just look weird. They'd get depressed by all the failure, and would gain a reputation as the guy who hits on anyone, which is absolute poison, especially when women are in contact with each other in Facebook and love gossiping about weird guys.
As better advisers would say, "women can smell bullshit a mile away."
On the other hand, in forums there'd always be someone going in the other direction and get attention that way. You don't need ANYTHING to hit on women, "just smile and say hi!" But the point was, how to get the attractive women, who have a lot of options. Just saying "hi" or "just have confidence" were equally bad advice for how to get those women.
I'm veering off topic. But let me say that those blogs and forums did help me. One especially valuable piece of advice was, "don't settle." Too many guys will hold on to a girl because she gives them sex and company, and they're too afraid to leave that comfort. Which means they'll break up later instead, after several years, having wasted those youthful years when they could have found someone else. I could have settled in two relationships, but I didn't, and so I found the girl who was better for me. And I did that by another piece of useful advice: Instead of the nonsense "You'll find someone when you stop looking" which is what people say when they have no idea, they won't stick their neck out with actual advice, and they think anything that is a paradox must be wise, I followed the advice "Get out there." Keep looking through different venues. Don't stay in your hobby if it gives you nothing - you know attractive women don't stick around for a hobby when they see there are no hot guys there. Be that goal-oriented yourself. If I hadn't followed this advice, I would have settled and wouldn't have found my current girlfriend.
I think this is good advice for sports and work as well. Don't get stuck just because it's comfortable, if it doesn't lead anywhere. Don't fool yourself with talk about loyalty and hopes that things might change. Make the change yourself. Sailer mentions Trump - in his professional life he was constantly trying new ideas, and that is the case with a lot of successful people. Look up the "Google Graveyard" to see how that company has tried and ditched dozens of things. It's just that in the end you only hear about the things that work, and the only advice the successful will give you is a variation of "work hard!" They don't mention how they tried and failed, then switched and tried something else.
Ben Franklin offered some good advice in his Autobiography. I was particularly impressed with his lesson on maintaining courtesy in a debate. I wish more people would follow this advice on the internet.
"[A] Quaker friend having kindly informed me that I was generally thought proud; that my pride show'd itself frequently in conversation; that I was not content with being in the right when discussing any point, but was overbearing, and rather insolent, of which he convinc'd me by mentioning several instances; I determined endeavouring to cure myself, if I could, of this vice or folly among the rest, and I added Humility to my list, giving an extensive meaning to the word.
"I cannot boast of much success in acquiring the reality of this virtue, but I had a good deal with regard to the appearance of it. I made it a rule to forbear all direct contradiction to the sentiments of others, and all positive assertion of my own. I even forbid myself, agreeably to the old laws of our Junto, the use of every word or expression in the language that imported a fix'd opinion, such as certainly, undoubtedly, etc., and I adopted, instead of them, I conceive, I apprehend, or I imagine a thing to be so or so; or it so appears to me at present. When another asserted something that I thought an error, I deny'd myself the pleasure of contradicting him abruptly, and of showing immediately some absurdity in his proposition; and in answering I began by observing that in certain cases or circumstances his opinion would be right, but in the present case there appear'd or seem'd to me some difference, etc. I soon found the advantage of this change in my manner; the conversations I engag'd in went on more pleasantly. The modest way in which I propos'd my opinions procur'd them a readier reception and less contradiction; I had less mortification when I was found to be in the wrong, and I more easily prevail'd with others to give up their mistakes and join with me when I happened to be in the right."