In case of losing weight, it very much does. You don't even need to do anything, you need to
not eat (as much). Given high heritability of obesity it may very well be that some genetic configurations make it harder to stop eating. Plenty of studies show that most fail at dieting. Statistically speaking, it may be impossible to lose weight for most. So if you don't believe in even soft free will, you may as well conclude it is in fact impossible for these people to lose weight.
Alternatively, one could claim many simply don't want to lose weight. Then it should be fair game to claim many don't want to improve their intelligence.
Dual n back studies are a good starting point. Could go through gwern's article [0]. Which I very much disagree with, but it does cover a lot of research. He essentially concludes the active placebo studies that produce as many gains as dnb prove dnb doesn't work. But without ground truth there's no way to know these active placebo gains are fake. Many of these active placebos are other cognitive training methods, it's perfectly plausible they may not be placebos at all. IMO we can only conclude that if dnb does work it isn't uniquely great.
Another thing to remember - if we want to determine if it is possible to improve intelligence we should care about maximum gains not average gains. Again, without ground truth, one cannot simply claim big gainers are meaningless outliers that can be discounted. There may not be anything producing 2 SD on average (though plenty showing much more than the 3 points you mention), but many such improvements have been recorded.
Imagine weight was something we couldn't observe or understand. Based on statistical science, many may similarly conclude it is impossible to change it.
[0] https://www.gwern.net/DNB-meta-analysis
Alternatively, one could claim many simply don't want to lose weight. Then it should be fair game to claim many don't want to improve their intelligence.
Dual n back studies are a good starting point. Could go through gwern's article [0]. Which I very much disagree with, but it does cover a lot of research. He essentially concludes the active placebo studies that produce as many gains as dnb prove dnb doesn't work. But without ground truth there's no way to know these active placebo gains are fake. Many of these active placebos are other cognitive training methods, it's perfectly plausible they may not be placebos at all. IMO we can only conclude that if dnb does work it isn't uniquely great.
Another thing to remember - if we want to determine if it is possible to improve intelligence we should care about maximum gains not average gains. Again, without ground truth, one cannot simply claim big gainers are meaningless outliers that can be discounted. There may not be anything producing 2 SD on average (though plenty showing much more than the 3 points you mention), but many such improvements have been recorded.
Imagine weight was something we couldn't observe or understand. Based on statistical science, many may similarly conclude it is impossible to change it.
[0] https://www.gwern.net/DNB-meta-analysis