On the other hand, I buy all of the data suggesting religious people are happier than others. They have built-in community, friends, relationships, guidance on how to live a good life. I was religious as a teenager and it was terrific. I had a great time in bible study, met interesting people I loved, even met girls and had an outlet for my singing. But as I got older, I can't do it any more because I don't believe the doctrine. I can't force myself to believe something I don't believe. In spite of how much better I believe my life would be if I was religious, I can't be.
I don't know that identity is really all that malleable. You either identity as something or you don't, and the reason is rarely if ever "I read a self help book and convinced myself this is who I am."
The part you really need to challenge, which will help in all areas of your life, is to settle the question: "to what extent do I believe I should do things that are good for me?". Every day you go without any plan or committed effort towards your health and exercising is a day you answered, "very little extent". for sake of text length im going to skip a lot of detail, but if you're like me then this eventually leads to a question of "how do I restore faith in myself?"
a thought experiment that i read somewhere (and maybe tweaked) that i use is a "post body swap" mentality. If you are willing to accept accountability and responsibility for whatever is in your past, then you no longer need to identify with it, and can treat every single new day as if it is your first time in this body. A kind of "live every day like it's your first" mentality. It has helped me recover from a lot of tough spots where i had an overwhelming amount of 'backlog' to deal with.
phrased differently, you look at your life as if you have just inherited it. you died, met God, and He said "i dont normally do this, but im sending you back for another shot in a random <yours> body".
the point isnt to trick yourself, you dont need to, there is no trick. it is simply a reminder of the free will you had already possessed prior to the thought experiment. that this is always your life to live however you want moving forward.
imagine you woke up in someones body who is more out of shape than you are currently, to the point you cant do things you currently enjoy doing. would you take the obvious path to start training to at least be able to do the things you were previously used to doing and see how far you get, or would you put in work to figure out how to change the way you live to better fit the new body?
your life is the way it is right now largely due to momentum from your past, not your current identity. identity updates really are not necessary to improve your life, and you arent identified by your momentum - even if that momentum has labels people use to describe it
For me this manifested on the intellectual plane. At times in the past I wanted to intellectually be “into XYZ”, like mathematics, for example, or some other subject matter. I had the aptitude and certainly the capacity to focus, enough to develop genuine expertise over time. But then I found that, in truth, I did not genuinely enjoy the subject matter enough to delve so deeply. I liked the idea of being someone who had cultivated rigorous mathematical expertise, but not actually being that person in reality, so it could never be my identity naturally, it would remain maximum effort as long as that were true.
It’s strange to me how we can convince ourselves to want something we don’t actually value intrinsically. But I suspect that’s a longstanding feedback loop in evolutionary psychology.
On the converse side of the story, I posit you can also get pretty far in stagnation of actual personal growth / progress by simply convincing everyone around you deceptively of a specific identity, and have that be validating enough to preclude cultivating that identity in earnest. Another trivial example: the “smartest guy in the room” effect. If you are sufficiently smart, or surround yourself with individuals who won’t challenge you intellectually and default to being deferential, you can certainly feel pretty smart, and have that maladaptively/falsely validate your sense of identity as the smartest-in-the-room type of personality.
TL;DR: I think the “make it your identity, then effort towards action comes naturally” is a powerful model for self-motivation, but it has meaningful failure modes—notably, it’s hard to force if you’re not genuinely into it, and sociodynamic feedback loops impacting personal sense of identity can collapse or even pervert the entire approach.
Karen Horney (20th-century German psychoanalyst) in her book "Neurosis and Human Growth" talks quite a bit about this failure mode. The relevant bit I want to share is her talking about how a person may be in a state of neurosis due to not feeling like they are living up to their idealized self -- and that a commonly destructive response to that neurosis is trying to force everyone around them to treat and perceive them as if they were that idealized self and not the flawed real self they are (regardless of whether the people around believe or are deceived into believing that, which is where she diverges from your point a bit but I think you're touching on very similar things).
My sense of who I am has not changed since I graduated from high school. College, jobs, buying a house, becoming a parent, nothing has really changed that.
The helpful suggestion of Atomic Habits is that instead of saying "I am someone who exercises" and setting a goal of running a marathon, you just go out for a run, or a walk, of any length until you've proven, again to yourself, that this is a habit you are going to keep.
But I disagree with the rest of your interpretation as stated here. The cart can’t come before the horse otherwise how useful is it to sparking motivation.
I understood the insight basically in the reversed, If your goal is to run a marathon, and you can’t find the motivation to train. If you orient towards an identity that being a runner (join a run club, buy running by apparel, watch track and field, research endurance training, subscribe to floTrack, peruse old LetsRun forum posts in your free time, talk about how great a runners high is, explore new locales during vacation by going for a run, decide you need to suddenly fix your pronation with custom orthotics your other runner friends swear by it, etc. etc.) you do that deeply enough and with genuine commitment that you start to think of yourself as a runner in earnest, why not you live it in every way other than racking up mileage. Now suddenly going out for a long run or going in a run every single day, or training for a race might just feel like the normal thinks to do because you’re a running and less like the effortfully endeavor to train for a marathon. Suddenly putting on your shoes and going for a quick tempo run sounds … not dreadful. maybe, even like something you genuinely want to do by then end. and the more you do it the more that is reinforced. you actually are a runner now. no pretending. going for a run isn’t a active decision each day—it’s what runners do.
What you describe seems like the converse to me. “You want to run a marathon, instead of convincing yourself that you are into running by weaving that into your sense of self… just go out for a run, or walk, of any length until—what if I don’t want to go for a run? don’t feel motivated. not even for a walk. besides, i’m not even a runner so what good would one random run do? I’ll do something else instead Id rather be doing, anything actually. … you’re probably never going to prove to yourself anything other than “finding motivation to run is hard” and certainly you’re not training for a marathon any time soon.
My point about failure modes was, sometimes you adopt the new identity for yourself and it goes like I outlined above. great… atomic habits. But sometimes you do it and realize in becoming that identify — you actually don’t like it, it’s not who you want to be (e.g. you hated flotrack, never showed up to run club, etc.) that becomes an impasse because you realize you don’t actually value orienting yourself in the world that way. In this case it wouldn’t work to motivate you any more than sheer willpower and effortful discipline. “I don’t want to be a runner, i just want to run a marathon.” ok, then put on your trainers and prepare for a slog.