Coincidentally, in the wake of the Gino/Ariely scandals, I was reviewing the "state of scientific research opinion" about "grit" and "mindset."
The verdict from google is that many of the initial news-making studies have failed to replicate, in other words, "grit" and "mindset" probably don't concretely exist, and don't have any practical application.
Mindset may or may not be scientifically provable, but as a tool for attitude change, it has been invaluable.
That slight shift from "I'm not good at it, I'll never be good so why try?" (fixed mindset) to "I may not be good at it now, but I can get better, at least better than than where I was" (growth mindset) has led me down so many paths where I've pushed myself to achieve things I never thought I could. The book/concept can be summed up to the above sentences, so you can apply it without ever reading the book.
Like most HNers, I grew up being really interested in computers. I was naturally talented in languages and humanities but was weak at math (I failed math in high school 3 semesters in a row).
If I had adopted the fixed mindset of "I'm an arts person, math isn't my thing, I'll never be able to do a degree in CS or anything like that," I would not have ended up where I am now. Instead I told myself "even with my lack of talent, I want to see if I can push myself to do at least 1 technical degree so I can work with computers". I still struggled greatly with math, but realized that math was just a language like any other but with stricter rules, so I applied my ability with languages to the study of math. This worked OK in undergrad where math was more mechanical, but worked out really great in grad school, where math was more abstract -- which resembled the thinking behind natural languages more. I now have a Ph.D. in numerical optimization.
Whether you use the word "mindset" or not, believing that your abilities are not fixed, but that you can grow if you apply effort (even if you never become the best) changes your attitudes toward so many things in life and makes it possible for you to achieve more. It's a small change in thinking that pays compound interest over a long time.
Congratulations on what you've accomplished through your positive attitude and hard work!
It seems reasonable to me that diligent people with a positive attitude do better in the long run. And as far as I can tell, your positive attitude and diligence were self-generated.
The "scam" is ['researchers,' not you] claiming that what you've done for yourself, can be bottled, distilled, and taught in a classroom, or through millions of copies of a book, or huge speaking and consulting contracts, etc. That sounds good, but seems to not be true, or at least not be based in science.
Sometimes simple ideas need a bit of marketing and "naming" so that we can concretely pin our actions to a concept that we can anchor on.
I may not have had the language of "mindset" then, but now that I have it, I'm more conscious of it and can communicate the idea succinctly. It's making something previously tacit explicit. I think there's value in that.
Currently I am reading the book Grit by Angela Duckworth. The author cites studies of grit and has done much research on the subject. Are you suggesting that that research does not replicate?
The verdict from google is that many of the initial news-making studies have failed to replicate, in other words, "grit" and "mindset" probably don't concretely exist, and don't have any practical application.