My concern is generally that those self-help people practically never provide reasonable evidence for their claims, nor do they provide reasonably detailed accounts of how they evaluated their methodology.
In fact, the vast majority of self-help advice I've seen in my life so far was entirely based on anecdotal evidence, survivor bias, obviously inadequate generalizations ("if I can do it this way, you can do it this way, too"), and an incredible amount of aggressive immunization to critique ("if you're sceptical about anything I say, you already have the wrong mindset and will never achieve anything"). It's very off-putting to someone with a background in science.
I'm not sure I require proof as such. But I am more likely to give something a try if I think there is something that might help me. I know that nobody fits into the statistical mainstream for everything.
In fact, the vast majority of self-help advice I've seen in my life so far was entirely based on anecdotal evidence, survivor bias, obviously inadequate generalizations ("if I can do it this way, you can do it this way, too"), and an incredible amount of aggressive immunization to critique ("if you're sceptical about anything I say, you already have the wrong mindset and will never achieve anything"). It's very off-putting to someone with a background in science.