The Embodied Theory of Stress: A Constructionist Perspective on the Experience of Stress

An emphasis on the physical body in an analysis of psychological stress is hardly novel. Volumes of research have established that the stress process involves numerous biochemical and electrophysiological variables that represent activity throughout the nervous system as well as various psychological and physiological changes (Aguiló et al., 2015; Gianaros & Wager, 2015). Physiological activity has, however, primarily been used to operationalize responses to and effects of stress (Aldwin & Werner, 2012; Lebois, Hertzog, Slavich, Barrett, & Barsalou, 2016).

Considering stress from the perspective of embodiment places that physiological activity in a new light. An embodied perspective raises questions about the distinctions between psychology and physiology in those interactions, as well as the distinctions between person and situation (Barrett & Lindquist, 2008; Barsalou, Niedenthal, Barbey, & Ruppert, 2003). Research and theory from this perspective emphasizes the reciprocal nature between psychological and physiological processes. Collectively, findings have indicated that the interaction between the two influences emotions and information processing as well as social interactions and cognitive performance (Barsalou et al., 2003; Niedenthal, Barsalou, Winkielman, Krauth-Gruber, & Ric, 2005; Winkielman, Niedenthal, & Oberman, 2008). This article incorporates those findings with theories of stress and emotion to present a more integrated understanding of the experience of psychological stress. The embodied theory of stress (ETS) that results from synthesizing knowledge in those areas represents a constructionist approach.

Perspectives on Stress

The concept of stress can be vexing for psychological scientists. The term has substantial popular recognition and understanding, but the related experiences vary in a way that presents a challenge for precise measurement and comparisons (Kagan, 2016). Indeed, researchers have argued that the term stress should be eliminated from use in scholarly work because of its varied use (Baum, 1990; Levine & Ursin, 1991). Epel and colleagues (2018) offered a less drastic suggestion in presenting a set of standards for describing measures of stress. Two of those standards are particularly applicable to the current discussion: timescale and life period.

Timescale refers to the length and frequency of exposure, with four categories commonly represented in research. Acute stressors are short-term and include situations that require an active response as well as those that do not require a response, known as passive stressors. Chronic stressors are ongoing—although previous works vary in the duration, Epel et al. (2018) suggested the criteria of 6 months or more. Daily hassles or daily event stressors are frequent and created by day-to-day life, such as traffic or meal planning. Life events are episodic and more extended than are acute stressors and include, but are not limited to, traumatic events. Life period refers to the age at which the individual is exposed to the stressor. Epel et al. suggested differentiating between four periods: in utero, childhood, adulthood (18 years of age and older), and cumulative across the life span.

Within those timescales and life periods, the experience of stress can be considered in terms of two general components: exposure and reactivity, or response, to that exposure (Bolger & Zuckerman, 1995; Epel et al., 2018). Exposure represents a potentially stressful event or condition, the focus of the experience of stress (McGrath & Beehr, 1990). Reactivity, or response, represents the subsequent psychological and physiological reactions (Bolger & Zuckerman, 1995; Epel et al., 2018).

One influential theory of the stress process, the cognitive appraisal theory (Lazarus & Folkman, 1984), describes exposure as the result of ongoing interactions between the individual and the environment—the inherent “struggle to manage the pressures of daily living,” (Lazarus, 2007, p. 35). The theory can be applied to understand stressors of various timescales in childhood or adulthood. Stressor reactivity is described in terms of appraisal and coping. According to that model, individuals are constantly appraising their transactions with their environment. Transactions that are appraised as stressful (i.e., as a threat, challenge, or harm) require coping. Coping refers to the processes used to alter the stressor, the appraisal, or the results of the appraisal (Lazarus, 1993).

The biopsychosocial model of challenge and threat incorporates the appraisal component of the cognitive appraisal theory in conjunction with an arousal-based conceptualization of the concept of stress (Blascovich, 1992, 2013). As such, the model elaborates on the characteristics of exposure and reactivity. Exposure is operationalized in terms of a situation that is personally relevant and that requires performance that is evaluated (Blascovich & Mendes, 2000). More specifically, the model applies to situations that require nonmetabolically demanding performance with well-being or growth depending upon adequate performance (Blascovich & Mendes, 2000). In other words, the model focuses on acute stressors requiring an active response.

Reactivity, according to the biopsychosocial model, includes both cognitive and physiological components. Cognitively, situations are appraised on two dimensions: the demands they represent and the resources available to meet those demands (Blascovich & Mendes, 2000). Situational demands are assessed based, in part, on perceived danger and uncertainty as well as the effort required. Resource appraisals are based on the individual's disposition as well as perception of relevant knowledge, skills, and support (Blascovich & Mendes, 2010). Combining perceptions of demands and resources creates two possible appraisals: threat or challenge. When individuals perceive they do not have sufficient resources, the situation is appraised as threatening. When resources are adequate, the situation is appraised as challenging. Those appraisals influence feeling and behavior as well as physiological activity, although the biopsychosocial model emphasizes the physiological activity (Blascovich & Mendes, 2010).

According to the model, challenge and threat appraisals result in different cardiovascular responses as a result of activity in the sympathetic adrenal medullary and hypothalamic pituitary adrenal axes (Blascovich, 2013; Seery, 2013). Challenge appraisals are associated with release of epinephrine, an increase in cardiac output similar to aerobic exercise, and a decrease in total peripheral resistance (Blascovich & Mendes, 2000; Blascovich, Mendes, Tomaka, Salomon, & Seery, 2003). Threat appraisals are associated with increased activity of the pituitary−adrenal−cortical axis, which inhibits the release of epinephrine (Blascovich & Mendes, 2000). Cardiac output does not change with threat appraisals, and total peripheral resistance is stable or increases (Blascovich et al., 2003).

The biopsychosocial model is based on an arousal regulation sequence that begins with stimulus exposure and subsequent cognitive appraisal, including biological factors and physiological arousal (Blascovich, 1992). Simply put, the psychological process of appraisal influences physiological activity (Seery, 2013). That sequence is supported by experimental findings that appraisals are not influenced by physiological activation (Blascovich & Mendes, 2010; Tomaka, Blascovich, Kibler, & Ernst, 1997). Research regarding arousal reappraisal, however, has suggested that individuals are consciously aware of increased arousal and have the potential to modify the appraisal of that arousal (Beltzer, Nock, Peters, & Jamieson, 2014).

Reappraising arousal as being representative of a challenge instead of a threat influences both psychological and physiological responses to stress (Jamieson, Nock, & Mendes, 2012). That reappraisal is associated with more adaptive physiological responses and improved cardiovascular functioning (Jamieson, Mendes, & Nock, 2013; Jamieson et al., 2012). Reappraising arousal also has implications for interpersonal interactions, given that it is associated with approach-oriented nonverbal signaling (Beltzer et al., 2014).

In addition, the effects of reappraisal on cognitive activity have a number of implications, given findings that the process results in reductions in attentional bias and increased perceptions of resources (Jamieson et al., 2012, 2013). In one study an intervention designed to encourage arousal reappraisal resulted in improved Graduate Record Examination performance in a laboratory simulation immediately after the intervention and when participants actually took the exam 1−3 months later (Jamieson, Mendes, Blackstock, & Schmader, 2010). Similarly, reappraisal was associated with improved exam performance in a developmental mathematics class (Jamieson, Peters, Greenwood, & Altose, 2016).

Embodied Cognition and the Stress Process

The implications of initial appraisals and arousal reappraisal raises the question of factors influencing the related cognitions. Whereas the biopsychosocial model highlights the situation-related content, findings from the perspective of embodied cognition emphasize the influence of bodily states (Landau, Meier, & Keefer, 2010). Arm flexion, for example, is associated with higher levels of approach motivation, with better problem solving, creativity, and memory when compared to extension (Cacioppo, Priester, & Berntson, 1993; Friedman & Förster, 2002). Outside the laboratory, this may influence both exposure and reactivity when individuals engage in activities resulting in arm flexion. Carrying a child or a bag of groceries, for example, may be accompanied by the perception of lower situational demands and of greater resources to meet those demands.

Studies of body position and cognition have suggested additional implications for day-to-day interactions. Individuals who are sitting upright report higher levels of self-esteem and demonstrate greater task persistence when faced with a potentially stressful task compared to those sitting in a slumped position (Nair, Sagar, Sollers, Consedine, & Broadbent, 2015). These outcomes may occur, in part, because posture influences thoughts and feelings about the self without conscious awareness (Stepper & Strack, 1993). Posture during success and failure can also affect locus of control, motivation, and depression-like feelings (Riskind, 1984). Collectively, these patterns can influence appraisals of both situational demands and the resources available to meet those demands.

Body movements involving multiple muscles also influence cognition in ways that may intersect with the exposure component of the stress process. Body movement can activate associated stereotypes—for example, moving slowly can activate stereotypes of elderly people and lead to the application of that stereotype in evaluating others (Mussweiler, 2006). Those processes have the potential to influence the situations to which an individual is exposed and, therefore, potential sources of stress. Music associated with particular ethnic groups may generate movements activating related stereotypes, for example, potentially leading to perceptions of prejudice in subsequent interactions. Those interactions may result in an episode of acute stress.

Considering the influence of the musculoskeletal system on attitudes adds to the insights about embodied cognition and the stress process. Collectively, investigations of embodied persuasion have indicated that the body contributes to the acquisition of attitudes as well as the potential for attitudes to change and the ways in which they are applied (Briñol & Petty, 2008; Briñol, Petty, & Wagner, 2011). For example, activating arm muscles is associated with the degree to which an individual likes an object, with flexion resulting in more positive attitudes and extension more negative (Cacioppo et al., 1993). Outside the laboratory, then, day-to-day activities engaging those muscles may not only have the previously mentioned benefits but also decrease passive stress because the individual is more positive about various encounters.

Findings have also indicated that body position affects the degree to which one thinks about a topic and the nature of those thoughts (Briñol & Petty, 2008; Briñol et al., 2011). In one study, participants who were lying on a cushioned table were more likely to think about a message more carefully and express agreement with an argument than were those who were standing (Petty, Wells, Heesacker, Brock, & Cacioppo, 1983). These patterns may influence chronic and life event stress because waking body positions are typically upright and may, therefore, be associated with disagreement and lack of consideration of others’ viewpoints. Effects on the degree of thinking and nature of the thoughts also have implications for arousal reappraisal because they suggest body position may influence whether individuals engage in the necessary thought processes.

Embodied Emotion and the Stress Process

Theory and research in emotion may represent the most extensive—and historical—example of the embodied perspective. William James theorized that emotions are the result of responses in what is now referred to as the autonomic nervous system, prompting extensive analysis of the sequence of physiological and psychological events that ultimately support his premise (Laird & Lacasse, 2014). Indeed, it has been argued that “any complete emotion processing theory should take the role of the body into account” (Niedenthal, Wood, & Rychlowska, 2014, p. 245).

Findings related to embodied emotion contribute to an understanding of stress from a number of perspectives. Whereas Lazarus (1993, 2007) asserted that stress was actually a subcategory within the larger concept of emotion, Gross (2015) discussed stress and emotion as components of affect—a conceptualization that is more consistent with findings related to stress exposure and reactivity. For example, emotions are frequently cited sources of stress, and stress has been found to be negatively related to happiness (Levine & Ursin, 1991; Schiffrin & Nelson, 2010). In other words, emotions are part of the situations causing stress and are related to the experience of stress. Positive and negative emotions influence cognition and, therefore, reactivity (Blascovich & Mendes, 2000; Forgas, 2001). Emotions and the associated cues also influence appraisals directly (Blascovich & Mendes, 2000).

Although emotional expression and interpretation vary from person to person, emotions tend to be accompanied by distinct patterns of body movement and position (de Gelder & Van den Stock, 2011). Similar to the findings regarding movement and cognition, experimental results have indicated that body position not only serves to express emotion but also invokes affective states within the person (Duclos et al., 1989; Flack, 2006). These effects appear to operate independently of other input (Barsalou et al., 2003; Laird, 2007). For example, moving in a way that is associated with happiness increases positive emotion, whereas moving in ways associated with sadness increases negative emotion (Shafir, Taylor, Atkinson, Langenecker, & Zubieta, 2013).

Embodiment of positive emotions can influence both exposure and reactivity by impacting attention and behaviors (Fredrickson & Branigan, 2005). For example, the broadened attention associated with positive emotions may prevent passive stressors as individuals focus on stimuli that do not engage reactions. When reactions are engaged or when the stressor is active in nature, the broadened thought–action repertoire may influence appraisals of both situational demands and resources.

Embodiment of positive emotions also reduces the negative effects of stress (Ong, Bergeman, Bisconti, & Wallace, 2006). This may be, in part, because they contribute to the use of adaptive, broad-minded coping mechanisms, which, in turn, further enhance positive emotions (Burns et al., 2008; Fredrickson & Joiner, 2002; Gloria & Steinhardt, 2016). These patterns suggest that embodiment effects may contribute to the experience of positive emotions even when individuals experience chronic, unambiguously stressful life situations (Folkman & Moskowitz, 2000).

Perspectives on Embodiment

Integrating findings related to embodied cognition and emotion with existing theories of psychological stress suggests the stress process is consistent with other information-processing activities in being “influenced, informed, associated with, and sometimes dependent on perceptual, somatosensory, and motor resources” (Winkielman, Niedenthal, Wielgosz, Eelen, & Kavanagh, 2015, p. 151). The discussion thus far has focused on peripheral, body-based evidence of that influence, particularly the role of the musculoskeletal system. That raises a number of questions about the relative contribution of the physical body in the stress process, including whether it is fathomable that the contribution would result in a meaningful effect when considered in the context of the overall process.

Contemporary embodiment theories present a different perspective by considering embodiment in the context of neurological activity. Neuroimaging data indicate experiences are simulated in modality-specific brain systems, a process referred to as central embodiment (Niedenthal et al., 2005). Musculoskeletal activity, then, is one part of a larger brain-based process in which experiences are embodied. In addition to activity in the motor systems representing that musculoskeletal activity, those reenactments involve sensory systems related to perception and introspective systems (Barsalou et al., 2003; Niedenthal et al., 2005).

Modality-based simulations create the embodiment of psychological events even in the absence of external input, referred to as offline embodiment (Niedenthal et al., 2005). Given that, embodiment does not require musculoskeletal activation (Barsalou et al., 2003). At the same time, each simulation is based on variables in the real world. One navigates that world in a physical body with specific sensory, perceptual, and motor abilities that respond to the situation at hand, providing elements of the simulations (Barrett & Lindquist, 2008). Collectively, then, the body and the situation help create what is known as the mind (Barrett & Lindquist, 2008).

Psychological Construction

Niedenthal et al. (2005) noted that the contemporary, simulation-based theory of embodiment is in contrast to “computer” metaphors, where bodily connections are portrayed as “unsystematic, abstract, and fragmented” (p. 184). Contemporary embodiment perspectives also represent a fundamentally different paradigm from the stimulus–response model represented by appraisal-based theories of stress. The alternative paradigm, psychological construction, is based on the premise that brain networks are constantly integrating input from the body, external sensory input, and prior experience to form mental states (Oosterwijk et al., 2012). Neuroimaging suggests the processes that integrate the array of input are supported by the salience network within the brain (Oosterwijk et al., 2012).

The theory of constructed emotion, initially known as the conceptual act theory of emotion, details the processes that co-occur with that domain-general activity to construct the experience or perception of emotion. The theory is based on the premise that the human brain's penchant for categorization facilitates the process of making meaning (Barrett, 2009). One of the primary hypotheses resulting from the theory is that the combination of external sensory input and sensations from the body informs whether or not an individual categorizes the experience as an emotion (Barrett, 2012). The process of combining external and internal information is part of a psychological construction.

An individual experiences or perceives emotion when the construction fits with previous information in the category for that emotion (Barrett, 2014; Barrett, Wilson-Mendenhall, & Barsalou, 2015). Past experience, therefore, contributes to the process by influencing concept knowledge and categorization. That influence takes the form of conceptualizations representing the knowledge one develops about frequently experienced situations—referred to as situated conceptualizations. Those conceptualizations are represented as modality-specific simulations of the components of the situation, including people, objects, settings, and actions as well as psychological processes realized through introspection (Barsalou et al., 2003). Situated conceptualizations, then, reflect both the context of the prior experiences and the meaning of those experiences (Barrett, 2014; Barrett et al., 2015). Information accumulates and is integrated across systems as the emotion is represented in difference instances over time, creating the related category and preparing the individual for relevant action (Barrett, 2006, 2014). Integrating information across time and instances also allows for meaningful variation within the category (Barrett, 2014).

Emphasizing the role of the situation in emotion also has a number of implications for the embodiment of emotions via the interaction of neural networks. Conceptualizations are represented throughout the brain, including the sensory cortices, motor cortex, and insular cortex as well as the domain general core categories (Barrett, 2006, 2014). Retrieving information about emotional experiences also leads to simulations of various brain networks (Barrett, 2006). The resulting processes influence behavior and sensation in such a way that it contributes to the conceptualization applied in future instances (Barrett, 2014).

Considering stress and emotion as types of affect, as delineated by Gross (2015), suggests that the process of constructing and categorizing the two may have common elements. The common, domain general processes that contribute to similarity across conceptualizations of emotion likely contribute to similarities between emotion and stress (Barrett, 2014; Barrett et al., 2015). The experiences being categorized are also only one part of the social reality at any given moment and given that, the related processes operate in conjunction with those required for physiological functioning. Indeed, it has been argued that one of the primary functions of the brain is to monitor, predict, and regulate activity across the body to support survival of the human being and the species—also known as allostasis (Barrett, 2017; Sterling, 2012).

The Embodied Theory of Stress (ETS)

Synthesizing theory and research findings about stress, embodiment, and psychological construction suggests a new perspective on the experience of stress—the embodied theory of stress (ETS). This theory parallels the initial basis of the theory of constructed emotion in hypothesizing that situations are categorized as stressful, and consciously labeled as such, based on the unconscious, automatic integration of data from the body, the external environment, and previous experience. Both peripheral and central embodiment effects impact construction and categorization processes. The embodied theory of stress diverges from the theory of constructed emotion to explain the characteristics that differentiate experiences categorized as stressful from other experiences. More specifically, the premise of the ETS is that experiences categorized as stressful are accompanied by unique patterns of physiological activity.

Conclusion

The embodied theory of stress represents a unique perspective by eschewing the stimulus–organism–response paradigm, applying psychological construction to convey the complex psychological and physiological processes that result in an individual's labeling an experience with the word stress. It is important to note that the goal is to describe the processes individuals use to label their experience, not to present a definition of stress. That emphasis has the potential to create further complications in the definition of stress even as it enriches understanding of the related experience.