Cognitive, Social, Physiological, and Neural Mechanisms Underlying Self-affirmation: An Integrative Review

People are motivated to feel that they are adequate—that they are good, competent, and efficacious. When demanding environments threaten this sense of personal adequacy, they may experience stress that can hinder their wellbeing and performance in various contexts. To combat the negative consequences of this type of stress, researchers have explored using selfaffirmation interventions that engage participants in an act that reminds them that they are globally adequate in threatening situations. Despite the wide body of literature examining the effects of self-affirmation from a variety of perspectives, the underlying mechanisms of this intervention are still unclear, with investigations into this question relatively disjointed across fields. Thus, the primary aim of this review is to synthesize research on the cognitive, social, physiological, and neurological mechanisms of self-affirmation. This integration illuminates patterns that have emerged from mechanistic examinations of this intervention across different disciplines, highlighting reduction in defensive processing and broadened perspective as particularly important consequences of affirmation that may, in part, drive its beneficial effects. We suggest that integrative research approaches examining the mechanisms of affirmation on multiple levels of analysis and in multiple domains would further our understanding of the key ingredients of this intervention’s effects. People are motivated to feel adequate—in other words, to feel good, competent, and efficacious (Steele, 1988). Yet at some point, all individuals face threats to their sense of personal adequacy, resulting in stress that may hinder wellbeing and performance (Steele & Aronson, 1995). Threats to perceived adequacy come in many different forms, such as receiving critical feedback at school (Yeager et al., 2014), obtaining a diagnosis of a serious illness (Sherman, Nelson, & Steele, 2000), undergoing a high-stakes performance evaluation (Steele & Aronson, 1995; Tajfel & Turner, 1986), or facing negative stereotypes about the intelligence or competence of one’s social group (i.e., stereotype threat; Steele, 1977; Steele & Aronson, 1995). These threats can depress academic performance (e.g., Gonzales, Blanton, & Williams, 2002), worsen physical health (Inzlicht & Kang, 2010), and lower self-esteem (Cohen & Garcia, 2005), among other negative effects. To insulate individuals from psychological threat, researchers have developed interventions based on selfaffirmation theory (Steele, 1988)— specifically, the tenet that people are motivated not to maintain perceived adequacy in one specific context (e.g., being a “good enough” student), but rather to maintain a global narrative of oneself as morally and adaptively adequate (e.g., being a “good enough” person). These interventions capitalize on this idea by engaging participants in an act that reminds of their adequacy in threatening situations. For example, struggling in class may make a student susceptible to feeling inadequate (e.g., “I am not smart enough”). However, if this student is reminded of his/her adequacy in another context (e.g., his/her loving family and friends), the stress of the course Yale Review of Undergraduate Research in Psychology 5 is less likely to get under his/her skin and impact his/her core self-concept. Affirming one’s adequacy in a context unrelated to the source of threat shores up one’s global sense of adequacy and self-integrity, strengthening self-concept against threat (Harris & Napper, 2005; Steele, 1988). Researchers have implemented affirmation interventions in different forms. One common version is the valuesaffirmation intervention, which consists of an exercise requiring participants to think and write about their personal values (McQueen & Klein, 2006). Participants review a list of values, rank them from mostto-least important, then write a brief essay about why their top-ranked value is meaningful to them. Values commonly selected by participants include “relationships with friends and family,” “independence,” and “religion” (Cohen & Sherman, 2014). Self-affirmation interventions have successfully mitigated the harmful consequences of threatening situations in prior studies (e.g., Cohen et al., 2006; Cohen et al., 2009). Relative to those who did not self-affirm in conditions of high stress and threat, affirmed individuals have demonstrated improved grades, test scores, and academic motivation (e.g., Cohen et al., 2006; Sherman et al., 2013), better health and increased engagement in healthy habits (e.g., Harris & Epton, 2009), and improved psychological states, including heightened sense of belonging (Cook et al., 2012) and reduced negative thinking (Koole et al., 1999). In general, self-affirmation insulates participants from threats to personal adequacy, rendering them more able to adaptively cope in challenging situations (Cohen & Sherman, 2014). Despite the wide body of literature examining the effects of self-affirmation, the underlying mechanisms of this intervention are still unclear. Researchers have examined mechanisms of self-affirmation from a variety of perspectives, measuring potential mediating effects of executive resources (e.g., Taylor & Walton, 2011), allostatic load (Sterling, 2004), reward pathways in the brain (Cascio et al., 2015; Dutcher et al., 2016), and more. Notwithstanding these efforts, however, investigations of affirmation’s mechanisms have been relatively disjointed across fields. Our primary aim is thus to synthesize and review research on cognitive, social, physiological, and neurological mechanisms of the affirmation intervention to build a comprehensive picture of the work thus far. In undertaking this review, we hope to illuminate patterns that have emerged from mechanistic examinations of affirmation across different disciplines. This integration across cognitive, social, physiological, and neural fields will allow for better assessment of prevalent explanations of how affirmation exerts its effects, potentially illustrate crossdisciplinary links, and unveil mechanistic explanations that enhance our understanding of this intervention. Cognitive Mechanisms of the Affirmation Intervention Many studies have investigated the cognitive underpinnings of the affirmation intervention. This work clusters into four mechanistic themes: (1) affirmation reduces cognitive load, freeing up mental resources for more adaptive coping; (2) affirmation curbs defensive processing; (3) affirmation shifts information construal from concrete to abstract; (4) affirmation promotes a broader perspective on self-concept and threat. In this section, we review findings across these themes. Affirmation Reduces Cognitive Load When individuals encounter threats to their personal adequacy, they may experience an array of cognitive consequences, including negative rumination (e.g., McIntosh & Martin, 1992), impaired inhibition of intrusive thoughts (e.g., Hilt, Leitzke, Pollak, 2014), depletion of executive resources (Johns, Inzlicht, & Schmader, 2008), and reduced working memory capacity (Beilock, Rydell, & McConnell, 2007; Schmader & Johns, Yale Review of Undergraduate Research in Psychology 6 2003). Previous work revealing these cognitive consequences have focused on stereotype threat (e.g., Johns, Inzlicht, and Schmader, 2008; Schmader & Johns, 2003), but research on other stressors suggests that these cognitive processes broadly occur in response to threat (e.g., performance pressure or social evaluative threat: Beilock & Carr, 2005; psychosocial threat: Kuhlmann, Piel, & Wolf, 2005; physical threat: Mahoney, Castellani, Kramer, Young, & Liberman, 2007). Rumination, intrusive thoughts, and other cognitive disruptions in response to threat can have serious repercussions for performance and wellbeing (e.g., Croizet et al., 2004). These disruptions result in an increased mental load that can distract individuals from the task at hand (Mrazek et al., 2011) and deplete cognitive resources required for adaptive coping, selfregulation, and performance under pressure (Logel & Cohen, 2012). Research on the cognitive mechanisms of self-affirmation suggests that these interventions improve performance and wellbeing in part by curbing rumination (and thus cognitive load) in threatening conditions. For instance, in studies by Koole and colleagues (1999), affirmed participants ruminated less relative to control participants after receiving failure feedback from an alleged IQ test. Decreased rumination following affirmation may be explained by reductions in the accessibility of threatrelated thoughts (as measured through a word-fragment completion task; Schmeichel & Martens, 2005). These findings suggest that the intervention allows individuals to deal with threat by limiting cognitive load engendered by rumination and intrusive threat-related thoughts, allowing mental energy to be directed more constructively to other tasks. That affirmation reduces cognitive load is also supported by research showing that the intervention leads to improved working memory performance (Harris, Harris, & Miles, 2015) and problem-solving performance under time and evaluative pressure (Creswell et al., 2013). Furthermore, in paradigms meant to deplete cognitive resources—such as the cold pressor test and arduous numeric puzzle tasks (Schmeichel & Vohs, 2009)—affirmed participants showed less evidence of depletion, keeping their hands submerged in ice water and working on onerous puzzles longer than unaffirmed participants. This heightened self-control in demanding circumstances may be additional evidence that affirmation reduces cognitive load and depletion due to environmental stressors, unfettering cognitive resources to adaptively cope and focus on other goals. Affirmation Curbs Defensive and Biased Processing In addition to freeing up cognitive resources that augment coping capacity, selfregulation, and ability to focus on the