Hurt feelings: physical pain, social exclusion, and the psychology of pain overlap
Laura /. Ferris
Feeling hurt and hurt feelings: the psychology of pain overlap
Why does a break up hurt so very much? One explanation is that rejection, ostracism, or social exclusion activate the same gross anatomical regions in the brain that are associated with physical pain (Eisenberger, Lieberman, & Williams, 2003). The resulting social pain then represents the same feeling of unpleasantness that arises from physical pain (MacDonald & Leary, 2005).
The idea of social-physical pain overlap hints at a unifying concept of human pain and suffering. Pain is a primal and familiar experience - whether from injury, child birth, illness, or the myriad sources of painfulness that are part of life. Pain is common and recognisable as a percept (ouch!), but it is also complex (Auvray, Myin, & Spence, 2010).
Seminal research has highlighted commonalities between the experience of social pain (arising from interpersonal rejection, ostracism, or other forms of social exclusion and loss) and physical pain (Herman & Panksepp, 1978; MacDonald & Leary, 2005; Panksepp, Herman, Conner, Bishop, & Scott, 1978). Could the same neural architecture or neurochemical systems that promote physical survival underlie social connection? Do pain killers actually quell the heartache of separation and loss for human beings? These are the evocative implications of an overlap between physical pain and social pain.
What is pain?
The International Association for the Study of Pain (I ASP, 1994/2016) defines pain as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or is described in terms of such damage. Two key features emerge from this understanding of pain: a) the subjective nature of the pain experience, such that pain may be experienced in terms of tissue damage but absent actual damage; and b) the delineation of its sensory and affective components (Fernandez & Turk, 1992; Price, 2000). In this sense, pain is both a sensation and a complex drive for response - more like hunger, thirst or itch, rather than touch (see also, Auvray et al., 2010).
Like physical pain, social pain hurts - but to understand how connections between social and physical pain have come about, it is helpful to briefly look back at the recent history of pain theory and its development.
Historical considerations
Historically, the science of pain has been a study of the physical pain mechanisms falling largely within the domain of medicine. Early theories positioned pain as a phenomenon arising solely via the mechanistic stimulation of receptors. Rene Descartes’ enduring image of the flame as pain burns its path from foot to brain (or from body to mind) famously symbolizes the bodily machinery of pain from injury-event to painful experience (1644; see Bourke, 2012). This basic understanding of pain mechanisms served medical science well for centuries, and forms the basis of the concept of nociception still in use today (Brooks & Tracey, 2005; Duncan, 2000). But scientific knowledge about pain has seen transformational shifts over the centuries (Morris, 1991).
A biomedical approach sees acute physical pain as being generally triggered by nociception - i.e., through detection and transduction of noxious stimuli by nociceptors in the periphery or viscera. Specific and well-characterised receptors have been discovered that correspond to different pain inputs: mechanical (e.g., from pressure applied to the skin), thermal (e.g., touching a hot plate), chemical (e.g., strong acid on the skin), and cold pain (e.g., plunging the body into icy water). Noxious or nociceptive input is detected by receptors, transduced, and then received in the dorsal horn of the spinal cord before being relayed supraspinally, preserving distinct sensory qualities mapped to the region of detection (Schwarz & Meyer, 2005; Westhind, 2005). Acute physical pain is known to spark specific and complex physiological responses, evinced by increased skin conductance, faster heart rate, and higher levels of blood cortisol, adrenaline and noradrenaline, heralding painactivation of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system (Benarroch & Sandroni, 2005; Pacak & McCarty, 2000).
In a major turning point for pain theory, Melzack and Wall’s (1965) gate control theory of pain provided the catalyst for a shift away from a pain-as-nociception model. The central nervous system was ascribed capacity for descending control of pain inputs, and psychological factors were afforded greater status than mere reactions to pain. This facilitated an understanding of pain that went beyond what nociception alone could account for (for instance, cases of chronic pain, phantom limb pain, and other idiopathic pain syndromes; Biro, 2010). Over time, this new view of pain has given rise to a more inclusive approach
(Gatchel & Kishino, 2011), with some even defining pain as “...whatever the experiencing person says it is, existing whenever the person says it does” (McCaffery, 1968; cited in McCaffery & Beebe, 1994, p. 15). Those pains without an apparent mechanistic etiology have been gradually withdrawn from the category of “somatization” (Crombez, Beirens, Van Damme, Eccleston, & Fontaine, 2009), “psychogenic pain,” or as in earlier days, hysteria (Cope, 2009), and the lived experience of the person in pain became elevated in importance. In short, scientific examination of the biological and physiological mechanisms of pain has been exponential, leading to substantial empirical advancements in pain conceptualisation and treatment (K. D. Craig, 2009; Julius & Basbaum, 2001). However, advances in pain theory have moved beyond a purely biomedical concept of pain. These developments have opened the door for a more inclusive conception of pain.
Pain overlap theory
How does social pain fit into the story of pain? The idea of pain overlap challenges early theories of pain mechanisms because of the absence of specific or characterized social pain receptors in the body (Papini, Fuchs, & Torres, 2015). However, modern ideas of pain incorporate the experience of pain as a subjective sensory and emotional experience - one that may not be associated with tissue damage (Melzack & Katz, 2013). This concept means that parallels can be drawn between “feeling hurt” and “hurt feelings,” because if social pain hurts, then it is pain. This is a controversial premise, but one that reveals several possibilities in which to consider the overlap between social and physical pain.
MacDonald and Leary (2005) traced out the concept of pain overlap across psychological, evolutionary, and neurological domains. They pointed to the prevalence of linguistic metaphors that paint social pain as physically painful: feeling “crushed,” “wounded,” “emotionally scarred,” or like getting “a slap in the face” (p. 206). Since this time, researchers have taken a closer look at the overlap between social and physical pain (Eisenberger, 2008, 2012a, 2012b, 2012c; Eisenberger, Jarcho, Lieberman, & Naliboff, 2006; Kross, Berman, Mischel, Smith, & Wager, 2011). Neuroimaging studies have shown that physical pain is associated with activity in an extensive subcortical and cortical network, referred to as the pain matrix (Legrain, lannetti, Plaghki, & Mouraux, 2011; Melzack, 1999, 2005). This network integrates ascending signals and modulates descending feedback, and also includes the dorsal anterior cingulate cortex, insula, periaqueductal grey, primary somatosensory cortex and prefrontal cortex (Chapman, 2005; Coghill, McHaffie, & Yen, 2003; Eisenberger, 2012c; Tracey, 2010). A graded fMRI signature that correlates with subjective pain ratings has been proposed (Wager, Atlas, Lindquist, Roy, Woo, & Kross, 2013), but the extent to which biological correlates can presently represent multidimensional pain is contested (Miller, 2009), including in relation to pain overlap (lannetti & Mouraux, 2011).
Particular criticism has been levelled at the reverse inference made in substantiating physical and social pain overlap through co-activation patterns. lannetti et al. (2013) contest that overlapping brain activation equates to an exclusive overlap in subjective mental state (lannetti et al., 2013, p374), pointing to the heterogeneity of pain and the inability of current technologies to capture its diversity. Wager and Atlas (2013) touch the heart of the issue in saying that neuroimaging can generate and helpfully constrain cognitive theories “to the extent that particular patterns of brain activity are sensitively and specifically associated with particular types of cognitive processes’’ (p. 91). This debate continues as imaging and analytical techniques advance (Cacioppo et al., 2013; Lieberman & Eisenberger, 2015; Kotge et al., 2015; Woo et al., 2014); but ultimately, neural overlap reveals correlative activation (Poldrack, 2006), and not social-psychological content per se. Therein lie the richer details in terms of the thoughts and emotions underpinning how we anticipate, emotionally react to, consciously reflect upon and conceptualize pain.
By definition, examining overlap has also brought commonalities into sharp focus, with arguably less enquiry directed toward what makes these phenomena different to each other. Now, more than ten years on from the original fMRI findings, researchers have still tended to restrict the focus toward investigations that reveal similarities in the neural indices of pain (Eisenberger, 2015). Neural indices do provide an important biological constraint to psychological theorizing (Wager & Atlas, 2013). Biological correlates of the pain experience offer the chance of a “clean” measure of the pain experience, but presently reveal only restricted information about the psychological or social context in which it has arisen. Consistent with a biopsychosocial approach to pain (Engel, 1977; Gatchel, Peng, Peters, Fuchs, & Turk, 2007), it is scientifically worthwhile and deeply important to retain this psychological understanding when conceptualizing and interrogating pain overlap.
A rose by any other name? “Physical” and “social”
Aside from the debate surrounding the neural signature of pain, there are other important theoretical implications that stem from the comparison of social and physical pain. One such implication is evident in the language used to describe these experiences. The terms “physical” and “social” pain are used to differentiate pain on the basis of its source. Describing pain in terms of physical and social causes makes intuitive sense, but there are some important caveats. The labels “physical” and “social” provide a workable but imperfect way to describe and delineate these two pains, because defining pain based on its origin is controversial. The IASP definition specifically seeks to avoid yoking pain to a stimulus: pain is always a psychological state, and not necessarily proportionate to nociception (IASP, 1994/2017). The idea of pain overlap connects social pain with the apparent tangibility of physical pain, but modern pain theory eschews the idea that pain needs a physical cause in order to be “real.”
Accordingly, it is considered loaded discourse to label a pain that is felt in the body as physical: tautological at best (“all pain is physically experienced”), and a misnomer at worst (“only physical pain is real pain”). A phenomenological approach to pain aims to address these tensions, and proposes that all subjectively felt pain is pain. This unties it from any particular stimulus or objective cause and situates pain as a product of the brain (Melzack & Katz, 2013). Importantly, this also clears the path for different pain types to be brought together conceptually on the basis of overlap in subjective experience - because subjectively, these pains could feel the same.
Being mindful of this tension in nomenclature is worthwhile because the literature on pain overlap continues to evolve. MacDonald and Leary (2005) described social pain as “a specific emotional reaction to the perception that one is being excluded from desired relationships or being devalued by desired relationship partners or groups” (p. 202). This aligns with the notion that pain is subjective, but also pins down the experience as a mere reaction. Traditional biomedical perspectives on physical pain also captured cognitive and emotional dimensions of pain as mere reactions to painfulness, rather than components of it (Melzack, 1999; Melzack & Katz, 2013). Recent approaches treat pain affect as more than a reaction to sensation - it is now considered a critical constituent of pain. Bringing psychological dimensions like pain affect into the circle as constituents of pain has elevated their status, bringing these elements to the forefront as functionally significant components of painfulness (see for example, Fernandez & Turk, 1992; Price, 2000).
