[raxxorraxor]

I think there cannot be a single perspective for optimal behavior. If I work I want to be efficient, the opposite is true if I want to relax. When I want to have fun or be creative rationality isn't necessarily good company.

I also don't want to take every opportunity I get, that would be pretty exhausting. I would have opportunity to save some taxes if I invest a few hours into tax law. Certainly and opportunity and pretty productive. But I just don't want to because I hate doing taxes.

Sure, these models do not apply to individuals (although this fact is often neglected). Also a model is always a simplification. Intrinsic to that is that it will by definition only ever be approximative. It neglects parts of reality, hopefully the less important ones but you cannot be sure about correctness and extend of approximation.

For example if I know a behavioral scientist that I just don't like for any reason and he suggest I should exercise more, I might go eat an extra pot of ice cream. This would render "nudging" quite ineffective or worse have the opposite than the intended effect.

I think it is more constructive to accept limitations of a model. It can help for prognosis and diagnostics. Why is it for example that people exercise less? Probably work load or distractions from entertainment or whatever reason. I think the field should concentrate on trying to get answers to such questions.

Psychology is interesting and much of the content that cannot be replicated is probably still true under certain circumstances. But for generalization these circumstances need to be known.