What You Can Change and What You Can't: The Complete Guide to Successful Self-Improvement

The book's spine is Seligman's depth theory of change: the likelihood of successful modification depends on how deeply a condition is biologically or psychologically entrenched. It rejects two competing worldviews. The self-improvement and psychotherapy tradition assumes behavior is malleable through conscious techniques and willpower. Biological psychiatry assumes mental illness is physically caused, personality is genetically fixed, and change requires pharmacological or surgical intervention [citation:17]. Seligman positions himself between these extremes, using outcome studies to identify which interventions actually produce lasting change. He argues that panic attacks are shallow and readily treated with cognitive therapy, while body weight and sexual orientation are deep and largely resistant to voluntary alteration. The book is an empirical audit, not a motivational program.

Seligman argues that body weight is largely genetically determined and defended by evolutionary mechanisms, meaning most people cannot achieve or maintain the culturally idealized slimness promoted by the diet industry [citation:14]. He distinguishes overeating from being overweight, and contends that dieting typically produces temporary loss followed by regain. His advice is to focus on fitness and health rather than weight loss. This claim was controversial in 1994 and remains contested, though it anticipated later research on set-point theory and weight regain. A reader review on WorldCat notes that the book is now outdated on some treatment recommendations, specifically citing naltrexone for alcohol dependence as an advance since publication [citation:6].

The relationship is one of application and boundary-setting. Learned helplessness (1975) established that uncontrollable events produce passivity; Learned Optimism (1990) provided techniques for changing pessimistic explanatory style. What You Can Change and What You Can't extends this trajectory by asking a broader question: if some conditions are changeable through cognitive techniques, which ones are not? The book applies the outcome-research methodology Seligman developed in his depression work to a wider range of conditions—anxiety, phobias, alcohol use, sexual dysfunction, anger. Its contribution is the depth theory that organizes these findings: change is possible in proportion to how deeply entrenched a condition is. This framework is the conceptual bridge between Seligman's clinical research and his later turn to positive psychology.

A starred Booklist review singled out the last two chapters as the book's most significant contribution: first, a critique of the belief that childhood trauma determines adult behavior, particularly as exploited by the recovery movement, and second, Seligman's own depth theory of behavioral change [citation:17]. The reviewer called the childhood trauma critique 'devastating.' This positioning was notable in 1994, during the peak of recovered-memory controversies and the recovery movement's cultural influence. Seligman argued that childhood trauma does not necessarily shape adult life, and that a child's psyche heals faster than an adult's. The depth theory offered a structural explanation for why some conditions yield to treatment while others resist: it is not a matter of effort or motivation but of how deeply the condition is embedded.

The book's currency has declined in specific treatment recommendations. A 14-year-old reader review on WorldCat notes that the book is 'amazingly out of date' and cites naltrexone's effectiveness for alcohol use disorder as an example of an advance since publication [citation:6]. An Everand reviewer characterizes the book as 'outdated, makes sense given it was written around the start of the decade of the brain,' and observes that 'the field has advanced rapidly since the book was written' [citation:20]. The depth theory itself—the organizing framework—has been less directly superseded, but the specific success rates, treatment recommendations, and biological claims reflect a pre-genomic, pre-SSRI-dominant era of clinical research. The book remains valuable as a historical document of evidence-based self-help before the term was standardized.

The most persistent misreading treats Seligman's claims about unchangeable conditions as fatalistic or deterministic. The book's subtitle—'the complete guide to successful self-improvement'—sets up a tension that reviewers noted: it seems to promise more than any book could deliver, yet Seligman's argument is that accepting limits enables more effective action [citation:17]. He does not claim that nothing changes; he claims that misdirected effort wastes courage and resources. The second chapter of the book is titled 'Booters and Bootstrappers,' referring to the self-improvement tradition, and Seligman's critique is not that change is impossible but that the self-help industry systematically overpromises. A related misreading assumes the depth theory is a fixed hierarchy when Seligman presents it as a provisional mapping based on 1994 evidence—one that subsequent research could revise.