A new rationalist self-improvement book: the 12 Levers

Spencer Greenberg and Jeremy Stevenson have published 'The 12 Levers,' a rationalist self-improvement book that attempts to cut through the noise of the self-help industry. The authors systematically read over 100 of the most popular self-help books and reviewed more than 20 types of therapy, extracting every technique or method they encountered—roughly 500 in total. After careful categorization, they found that these numerous approaches could be subsumed under just 12 high-level psychological strategies, which they call the 12 Levers. The book also examines the evidence behind each lever, offering a data-driven alternative to anecdote-heavy self-help.

Key lessons from the research include that many self-help techniques are recycled or repackaged versions of older methods, such as mindfulness appearing under names like defusion, acceptance, or decentering across different therapies. Additionally, the authors found that many popular techniques lack robust scientific evidence; for example, a 2025 meta-analysis on cold exposure showed mixed results—some benefits at 12 hours but not at other time points, and no quality-of-life improvements after 90 days. The book includes historical stories to make each lever vivid, and pre-orders come with perks like a tool for applying the techniques.