Most people who fail to change don't lack discipline ? they're using the wrong tool for the job. Willpower can carry you through a hard moment, but it was never built to override months of automatic behavior, which is why the third or fourth attempt at change so often ends the same way the first one did.

The Setpoint Effect makes the case that lasting change doesn't start with better habits ? it starts with updating the internal model of "who I am" that's been quietly running your behavior on autopilot for years. Drawing on self-concept research, cognitive consistency theory, and a sharp rethink of the old psycho-cybernetics idea, this book lays out exactly why change reverses itself, what specific evidence actually moves a self-image, and how to recognize the discouraging flat stretch that shows up right before real change finally takes ? the exact point where most people quit.

You'll get a working model for why effort alone doesn't stick, a practical method for building evidence your old self-image can't dismiss, and an honest account of what this approach can't do, so you're not left chasing a promise that was oversold from the start.

If you've outgrown the advice to just try harder, this is the book that explains what to do instead.