Fears and Phobias
Fear is a normal emotional response to actual danger; it motivates individuals to either avoid the danger or to elicit adaptive species-specific defense behaviors, which reduces threat to life or general harm or loss. Phobias are exaggerated fear responses to specific stimuli that are not really as hazardous as the response suggests, and the avoidance and safety behaviors patients engaged in are maladaptive or unnecessary and often the maintaining feature of the disorder.
Every living thing intuitively responds to threat. Fear, a quick and normal emotional response to danger, motivates species-specific defense behaviors, such as the fight-or-flight response. Fears are considered rational, appropriate when such defense or avoidance behaviors are elicited in response to a definite danger; as such, the function of fear is to avoid harm or death. Anxiety is an inappropriate or irrational fear response triggered in the absence of actual danger. Exaggerated, irrational, and extreme manifestations of fear or disgust and avoidance of specific stimuli in the absence of proportional danger are considered specific phobias.
Anxiety disorders are highly prevalent in the population, afflicting approximately 18% of the U.S. adult population in any given year. For females, lifetime and past-year rates of anxiety disorders are 1.5–2 times higher than in males, a trend that is mirrored in the domain of specific phobias.
Few areas of mental disorders have been as clearly influenced by functional and evolutionary thinking as anxiety. Almost all anxiety researchers and clinicians accept the idea that normal, adaptive fear functions as a signal that triggers appropriate defensive response. Because anxiety constitutes an exaggerated, maladaptive response despite there being no objective, present danger, and because persistent attempts to remove such nonexisting threat contribute to its maintenance, it is generally considered maladaptive. Even if a stimulus involved mild discomfort or pain (e.g., wasps and injections), the fear or disgust response may be considered exaggerated compared to actual pain or danger. This includes the avoidance that may reduce general function, well-being, or health benefits.
Considering the phenomena people in general are most phobic of quickly reveals a list of possibly evolutionary relevant phenomena: heights, dark, strangers, small and large animals (and especially snakes and spiders), and open and closed spaces. Since none of these ancestral hazards are specifically dangerous today, evolutionary accounts of preparedness therefore ring true for most clinicians (Kennair 2007; Marks and Nesse 1994; Öhman and Mineka 2001). Further, governmental health and safety campaigns often attempt to instill fear toward specific stimuli, yet they commonly fail to do so. This is due to the hedonic valence of the stimuli, making our approach behavior to harmful stimuli (e.g., fat, sugar, speeding, drugs including nicotine and alcohol, unprotected sex, and speeding) problematic. Our desire to enjoy these things so much overrides their fear-inducing potential, to an extent that they through their availability present a challenge to our health in a modern, evolutionary mismatched ecology – even if they were not dangers in the EEA.
Acquisition of Phobias
For many decades, phobias were considered a result of conditioning. According to Mowrer’s behaviorist theory (Mowrer 1947), two types of conditioning were involved: first, classical conditioning, i.e., being stung by wasp, and, second, operant avoidance, e.g., avoiding a room with a wasp in it. However, many stimuli do not provide a basis for classical conditioning, and one often finds that those who have been stung are less phobic than those who avoid wasps due to their phobia. Model learning has also been offered as an explanation, but this only moves the explanation of phobia acquisition back a generation or more. The limitations of associative pathways were recognized early by anxiety researchers (Rachman 1977), and experimental research has challenged the generalizability learning or equipotentiality of stimuli (Seligman 1970; Öhman et al. 1976). Work by Öhman and Mineka (2001) considered how humans are prepared to fear specific stimuli. The recent years have seen an increased focus on non-associative pathways, championed by the longitudinal work of Poulton, Menzies, and colleagues (Poulton and Menzies 2002a, b). Recently, Sandseter and Kennair (2011) suggested that childrens’ tendency to engage in risky play might constitute a mechanism that reduces naturally maturing and occurring fears of ecologically relevant threats coinciding with the development of psychophysical and motor skills, thereby promoting approach and reducing safety behaviors. The mode of acquisition of phobias continues to be addressed from an evolutionary perspective (Hoehl and Pauen 2017).
Recent Evolutionary Developments
Recent evolutionary research is still inspired by the pioneering work of, e.g., Öhman and colleagues. Certain fears and phobias occur naturally during different stages of human development (e.g., separation anxiety and fear of heights) that follow a complex, yet stable, pattern (Boyer and Bergstrom 2011). Employing visual detection paradigms, recent developmental work has demonstrated that visual attention in infants and young children is prioritized for potentially dangerous stimuli resembling ancestral hazards, well before they acquire any threat-relevant fears. Others show that infants readily associate snakes with fear (DeLoache and LoBue 2009) and are quicker to detect the presence of spiders than various categories of biological distracter stimuli (LoBue 2010). Using a preferential looking and habituation paradigm, Rakison and Derringer (2008) demonstrated a perceptual template for spiders that generalizes to real-world images of spiders, but not for other nonthreatening biological stimuli in infants as young as 5 months old. These findings are in line with studies that show that other arthropods (e.g., bees/wasps) are not perceived as threatening as spiders (Gerdes et al. 2009; New and German 2015).
Other studies show that these threat-detection mechanisms are maintained in adults. Jackson and Calvillo (2013), for instance, demonstrated that participants completing a visual search task located evolutionarily relevant and animate objects fastest and with the least impact of high perceptual load, compared to evolutionarily novel and inanimate objects. Further evidence stems from research on an unusual but common phobia, trypophobia, in which images of holes instill fear. Conducting a spectral analysis on a variety of images that induce trypophobia, Cole and Wilkins (2013) found that fear-inducing stimuli had a spectral composition typically associated with a range of potentially dangerous animals. Kazanas and Altarriba (2017) demonstrated memory advantages for unknown (supernatural) predators. Overall, these findings echo evidence that animate objects are mirrored more closely than inanimate objects, independent of considerations about which pose more serious threats in modern environments.
In an original approach to the evolution of phobia, Miloyan et al. (2016) suggest that for humans, specific phobias demand a capacity for mental time travel. This may account for the chronicity of this disorder, as actual dangers in the EEA would need to be avoided consistently and over long periods of time, including mechanisms of planned avoidance.
The Special Case of Blood Injury Injection Phobia
The special case of blood injury injection phobia, the only anxiety disorder that leads to fainting of those affected, illustrates the adaptationist evolutionary approach to danger – an actual danger is countered by a relevant adaptive response. Rather than increasing adrenalin and activation, there is a fall of blood pressure, which might be the most adaptive response to severe blood loss (Kennair 2007; Marks 1988).
Despite the fact that phobias are not necessarily acquired through associative pathways such as conditioning, behavioral therapy – exposure therapy including response prevention – constitutes the most efficient treatment of phobias. In general, it seems that reducing avoidance and discontinuing safety behaviors lead to a decrease in anxiety levels. The idea that evolved mechanisms are malleable and that learning is an evolved function, which better makes us better adapted to our environment, is not at odds with an evolutionary perspective.
Generally, evolutionary clinical psychology has had little influence on mainstream mental health care. Most anxiety therapists will use evolutionary perspectives in psychoeducation, to explain the patients’ exaggerated responses and, in so doing, normalize these. The obvious exception is treatment of anxiety in general and phobias specifically. Beyond the understanding of the function of fear and safety behaviors, evolutionary perspectives have informed our understanding of predispositions to fear specific stimuli and how phobias and anxiety may mature through non-associative pathways. Recent work continues a tradition of considering specific evolutionary relevant stimuli and the evolved mental mechanisms designed to perceive these.
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