Cushman asserts that rationalization is rational (the non-rational process of rationalization is a useful fiction that improves subsequent reasoning, and thus it pays to rationalize). In this way, rationalization is considered adaptive as it would facilitate the putative “ultimate” goal of reasoning: maximizing biological fitness. However, there is ample evidence that rationalization does not improve reasoning. There is a substantial difference between the word “rational” in the sense used by economists (and to some extent in the target article), which reflects nominal desires and beliefs, and the common usage of the word “rational,” which often implies good or wise. However, beyond the circular level of something being termed rational because it seemingly fulfils one's nominal immediate desires, rationalization can be a defense mechanism that has been found to be associated with not only a developmentally lower level of psychological functioning, but also with a broad range of criminal and interpersonally destructive behaviors.

Psychological defense mechanisms are processes that operate largely outside of conscious experience and serve to reduce anxiety at a cost (distortion of reality). They can be conceptualized along a developmental hierarchy, reflecting both the ages at which a defense might be normal and the degree of psychological impairment if used in adulthood. The defense of rationalization allows individuals to cope with emotional conflict or other stressors by creating incorrect explanations that can alleviate their distress. Hence, the perception of reality is distorted in the sense that the correct, but painful, explanations, are avoided (Knoll et al. Reference Knoll, Starrs, Perry, Zeigler-Hill and Shackelford2016). Rationalization is generally found to be in the group of immature (or maladaptive) defense mechanisms (Andrews et al. Reference Andrews, Singh and Bond1993). Rationalization continues to show a decline even in the course of adulthood (Diehl et al. Reference Diehl, Chui, Hay, Lumley, Gruhn and Labouvie-Vief2014), which speaks not only to a maturity issue, but also possibly learning that it is not a long-term efficacious strategy (it might also reflect greater survival among persons less likely to use rationalization).

Nearly a century ago, Taylor (Reference Taylor1923) observed that the process of rationalization is associated with less, rather than more, mental awareness, as a result of suppression of thought. This blocking of thought and reason is part of why rationalization was later found to be a developmentally immature psychological defense mechanism. Far longer ago, an astute observer of human behavior noted: “And oftentimes excusing of a fault Doth make the fault the worse by the excuse” (Shakespeare, King John. Act 4, Scene 2).

The defense of rationalization has been found in many studies to be associated with antisocial behavior and antisocial personality disorder (a pervasive predatory or criminal orientation that is resistant to treatment). Various psychiatric diagnostic systems even include rationalization in the criteria for antisocial (sometimes termed dissocial) personality disorder (American Psychiatric Association 2000; World Health Organization 1993). The subgroup of disavowal immature defenses (rationalization, denial, and projection) are especially predictive of antisocial personality disorder (Blais et al. Reference Blais, Conboy, Wilcox and Norman1996). Perhaps unsurprisingly, rationalization of violence is associated with adolescent antisocial behavior (Calvete Reference Calvete2008), and “high self-esteem” can exacerbate the process of rationalizing antisocial behavior in predisposed children (Menon et al. Reference Menon, Tobin, Corby, Hodges and Perry2007).

In addition to antisocial behaviors, rationalization might also be a risk factor for the development of posttraumatic stress disorder (Price Reference Price2007).

Although Cushman defines rationalization as concocting desire or beliefs after an action so as to make the action appear rational, one prominent theory of criminal behavior asserts that neutralizations (a largely conscious cousin of rationalization) can precede an antisocial act, so as to decrease any possible internal resistance to perpetrating the act (Sykes & Matza Reference Sykes and Matza1957). Of course, after the first offense, it becomes more difficult to disentangle neutralizations and rationalization.

Rationalization might contribute to the development of alcohol abuse and alcohol dependence (Wombacher et al. Reference Wombacher, Matig, Sheff and Scott2019), and rationalization is differentiable from the well-known defense of denial in alcoholics (Ward & Rothaus Reference Ward and Rothaus1991).

The breadth of antisocial behavioral associations with use of rationalization is noteworthy. Rationalization is associated with engaging in “repeated and unwanted attempts by one person to initiate or maintain an intimate relationship with a specific, targeted, and unwilling other” (Brownhalls et al. Reference Brownhalls, Duffy, Eriksson and Barlow2019). Although such behavior might in itself be seen as consonant with Cushman's view of rationalization being a rational means of improving fitness, rationalization is also associated with perpetration of pedophilia and other child sexual abuse in both sexes (deYoung Reference deYoung1989; Jimenez Reference Jimenez2015; Neidigh & Krop Reference Neidigh and Krop2015; Rush Burkey & ten Bensel Reference Rush Burkey and ten Bensel2015).

Rationalization has been found to be highly prevalent among shoplifters (Cromwell & Thurman Reference Cromwell and Thurman2003). Rationalization has also been identified as one of the psychological processes that facilitate being a perpetrator of multiple murders and genocide. This applies in studies of a contract killer (Levi Reference Levi1981), perpetrators of the Rwandan genocide (Bryant et al. Reference Bryant, Schimke, Nyseth Brehm and Uggen2018), and Nazi physicians (Lifton Reference Lifton1986). It might well be argued that part of the appeal of Hitler's Mein Kampf (Hitler Reference Hitler1925) for the German voters was his rationalization that Germany could not have lost World War I because of its own intrinsic failures, so it must have been due to the Jews. In this case, the immature defense mechanisms of rationalization and projection are intertwined. Some of Hitler's followers likely accrued fitness benefits for a few years, but eventually, Germany lost yet another World War.

In conclusion, rather than the non-rational process of rationalization engendering useful fictions that improve subsequent reasoning, it has been found to be associated with real-world destructive behavior and no sign of improved reasoning even within the destructiveness.