The deep forest and its denizens have become alien. The arc of human habitation from cave to cabin to condominium is bent toward light, warmth and convenience leaving the stark, dark realism of nature behind. Scratching out a hardscrabble living on and in the soil punctuated by hunting and gathering in nearby woods engendered physical endurance and mental acuity. The forest and its trees were refuge and provender, familiar ground through which to move on foot in furtive quiet. No more. What woods are left have been regrown from the roots, their ancient forebears cut for fuel and furniture, to clear fields for plantation, or both. Cities occupy the epicenter of human habitation. Nature has been cast out from canyons of man-made rock structures that tower above the Sturm und Drang of perpetual movement on paved byways. Here and there a green space sometimes called a park may offer a vestigial glimpse of the land that was lost, although it may just as well have been given over to industrial or amusement activities. The hive of urban activity is surrounded by suburbs. Here an attempt to establish a modicum of balance between things of nature and things of man is limned with green grass thresholds to non-tree houses. The woods are further away, and you need to drive to get there.
Humans are adaptable. It may be one of our most important evolutionary traits in leaving Africa and setting out on a globetrotting diaspora about 75,000 years ago to reach the southern tip of South America at Monte Verde only 60,000 years later.  Before the advance of Home sapiens over Beringia, the expanse of the Americas was untrod by human feet, a pristine wilderness where the rules of nature were followed with sometimes brutal finality. These early immigrants made their way among the megafauna, killing and eating some and adapting better than others to survive as the last Ice Age gave way to moderation. These were the Native Americans who set up shop everywhere from the arboreal north and east to the cliff dwellings of the west. In the south, the Aztecs, Incas and Maya built cities to bridle burgeoning populations and trade, eventually reabsorbed by the forests they subdued only for a time. These early peoples certainly knew and respected nature; Indian legend is rife with animism. And then came the Europeans, whose adaptations sullied nature’s waters to fill cisterns, turn mills and empty sewage.
Adaptation is a blessing and a curse. As the new immigrant Euro-Americans docked on the east coast and headed west, it was something of a renaissance. Many came from the squalor of festering cities and crossed the ocean in cold, dark hulls to debark in what was literally a New World with no imposed order. Those who adapted survived and some flourished. It took about two hundred years to get all the way across the continent first by Conestoga wagon and then by rail and another hundred years to fill out the interior with a network of highways inspired by the autobahns of the German Third Reich. Forced emigration of the Native Peoples to reservations under duress along the Trail of Tears or after having been chased down and shot at Wounded Knee opened the land for its new inhabitants to settle, farm and hunt. In subduing the continent, they became adapted to being its master, decimating any of the other predatory animals like wolves and cougars that got in the way. Wolves were hunted to near extinction using the bounty system business model as a means to protect livestock brought west to feed the east; over twenty thousand were killed annually in the first part of the last century . Hunter Alexander Crowell killed the last mountain lion in Vermont in 1881.  With generational succession in an increasingly tame world, the wonders of the wild disappeared behind fences to mark the boundary where we can now drive by on the road that there was paved to get from somewhere to somewhere else. We have become adapted to the city and its suburbs. The woods have become an alien place, filled with unknown dangers that lurk in the minds of its beholders.
Fear results from the real or rationalized presence of danger, evil or pain. If attacked by a snarling dog, you run in fear. It is the realm of the amygdala, the primitive, ‘reptile’ brain at the base of the crenelated cerebral cortex that distinguishes our species. It is a major functional component of the limbic system, the neural network that applies the brain-processed inputs from the senses to operate the muscles of the arms and legs in response. In simple terms, the brain can be considered to have three levels. The first level directs autonomous acts such as breathing and heart beating, the third level processes information, and the second level is the switchboard between them. All animals have the first, primitive level; evolution of the mammals was quite likely the origin of the middle layer which continued to the third as an advantageous mutation for survival. Fear is one the inputs to the amygdala that triggers the sympathetic nervous system (SNS) resulting in the immediate “fight or flight” response, releasing the adrenaline for emergency action. The other amygdala input is sex; Sapolsky, who I am drawing from, provides the medical student mnemonic for the functions of the SNS as mediating the four F’s: Fear, Fight, Flight and Sex, avoiding one of George Carlin’s seven dirty words. The amygdala is surrounded in more evolved animals by the basolateral amygdala (BLA). It connects the thinking and reasoning pre-frontal cortex that has learned through life experience about new threats that need to be added to the watch list. The amygdala is the place where things that go bump in the night trigger the fear response., the BLA would account for fear of flying. 
A phobia is an irrational fear that becomes excessive and persistent. In psychiatry, it is one of a larger class of mental anomalies called anxiety disorders. Unlike fear, anxiety occurs in response to an unknown, vague, or internal threat that is imagined and anticipated. Sigmund Freud defined what he called anxiety hysteria as an awareness of lurking danger in the unconscious; this was based on his study of a little boy named Hans who was afraid of horses.  According to the Diagnostic and Statistical Manual of Mental Disorders, usually referred to as the DSM, anxiety is the result of a perceived future threat. Where fear invokes immediate action, anxiety is “more often associated with muscle tension and vigilance in preparation for future danger and cautious or avoidant behaviors.” Among the anxiety disorders, which include everything from panic attack to avoiding social contact, phobias concern a specific object or situation. Well known examples include fear of animals (zoophobia), fear of heights (acrophobia), and fear of being in closed spaces (claustrophobia). Agoraphobia is considered separately from the other phobias for reasons that are not clearly specified (there is spirited debate about the abundance and specificity of aberrant mental conditions categorized by the DSM, among them Tobacco Use Disorder). Agora means marketplace in Greek, so the condition quite logically concerns anxiety about marketplace activities like crowds, queues, and public transportation; its prevalence has assuredly been impacted by school, church, and mall mass shootings that leave even those without agoraphobia wondering about whether they will be the next target of the of a gun-toting grim reaper. It is estimated that eight percent of the U. S. population has a phobia of some kind and that three quarters of phobic patients have multiple objects or situations that ruffle their mental feathers. 
The most common phobia is zoophobia, the fear of animals. The current theory is that a phobia has its origination in the occurrence of an actual frightening event like a very loud noise conjoint with what would normally be a neutral event, like an encounter with an animal (Sapolsky’s example is the theme music from the movie Jaws). The hypothesis was validated in a series of experiments by psychologists who were able to induce phobic fear of rabbits in a boy named Little Albert in 1920; human testing of this sort would be in rampant violation of what have become stringent ethical codes for testing, particularly for children. Once a phobia is established as a part of the neural architecture, the individual will go to great lengths to avoid any circumstance that might lead to its occurrence. Ergo, if you are afraid to go down to the woods today because you’ll be in for a big surprise, (some readers may not recognize the lyrics to the popular Teddy Bears Picnic: “If you go down to the woods today, you’re in for a big surprise, if you go down to the woods today, you’d better go in disguise” etc.) you simply don’t go there and avoid the possibility altogether. More recent clinical observations have led to a somewhat nuanced cause of phobias in having a genetic as well as an environmental factor; some people are more prone to them than others. Whatever may be the origin, psychiatrists are in nearly unanimous agreement that “self-exposure to the feared situation is the basic principle of all treatment.”  So the best policy for fear of the woods and its animals is to go down to the woods today and seek them out, even if you’d better go in disguise.
There is some irony to the argument that post-modern humans (when walking became something you only do to get to your car) must go down to the woods to reduce stress levels by hiking only to dampen the effect with the stressful anxiety of zoophobia. But that is what the doctor ordered. If one digs further into the neuroscience of behavior, the oxymoron makes sense. A learned fear is stored in the hippocampus (the unusual name that refers to its shape – something like a seahorse which in Greek becomes hippo for horse and kampos for sea monster) that is buried deep in the brain. While not yet fully established, it is believed that the hippocampus is acts something like a switchboard that connects the amygdala with the memories that originate in the prefrontal cortex (PFC), the most advanced area of the brain; it is figuratively called ‘the decider.’ The key point is that things that the brain learned to fear are equally subject to learning to fear no longer. This has been demonstrated in the laboratory. Rats can be conditioned to fear a tone by giving them a shock whenever they hear the tone; after a time, the tone alone will instigate the fear response (the hippocampus sends a signal to the amygdala). Conditioning is well established according to the Pavlovian demonstration of dogs salivating at the sound of a bell. The tone-conditioned rats can be unconditioned by repeating the tones without shock randomly over time. While not yet well understood, the PFC demonstrably learns that tones do not necessarily mean shock, and sends a countervailing signal that overrides the original fear signal. The main point is that phobias can be unlearned by repeated exposures to the cause of the phobia absent the fearful outcome. 
How do you deal with fear of the animals of the woods? Mitigation of anxiety is not settled science. The complexities of the brain and its neural corporeal network are at the forefront of medical scientific research, the psychiatric implications will follow in time. There are currently four generally accepted modalities that are proffered by various practitioners for dealing with anxiety: (1) The Cognitive Model to change the thought process; (2) The Exposure Model to face down your fears; (3) The Hidden Emotion Model to allow more open expression of feelings; and (4) The Biological Model.to take drugs for anxiety abatement  For zoophobia, only the first two really apply, as expressing your emotions to a wild animal is hardly going to help much and taking tranquilizers to quell the beasts within is inadvisable on potentially rocky and slippery trails. One promising approach would be to combine knowledge-based familiarity with the animals that are the subject of fear (Cognitive Model) with direct observation under controlled circumstance of confrontation (Exposure Model). There are any number of animals that may elicit fear, recall that Freud’s Hans was afraid of horses and Little Albert was afraid of rabbits. My experience leading people through the woods with reassurance against bodily harm has most frequently been on account of bears, snakes, and spiders. According to the renowned biologist E. O. Wilson, “These were among the ancient perils of the prehumans and early human hunter-gatherers across millions of years. Our distant ancestors regularly faced injury or death while hunting for food. … It was safest to learn fast, remember the event long and vividly, and act decisively without involving rational thought.”  Phobias are an overreaction to a reasonable fear that can be overcome by experience and knowledge that passes into cognition. The rational mind can then override the amygdala by disguising that fear with an inhibitory message to subvert it. So, if you go down to the woods today, you’d better go in (cognitive) disguise.
1. Meltzer, D. “Monte Verde and the Pleistocene Peopling of the Americas” Science, 02 May 1997: Vol. 276, Issue 5313, pp 754-755
2. Mech, L. and Boitani, L. Wolves: Behavior, Ecology and Conservation. University of Chicago Press 2003, p. 448.
3. Larue, M. “America’s Cat is on the Comeback” American Scientist Volume 106 Number 6, November-December 2018. Pp 352 – 358.
4. Sapolsky, R. Behave, The Biology of Humans at our Best and Worst. Penguin Press, New York, 2017 pp 15-50. This book is essential reading for those without a background in neuroscience to come to an understanding about how the brain works.
5. Sadock, B. and V. and Ruiz, P. Synopsis of Psychiatry 11th edition, Wolters Kluwer, Philadelphia, 2015, p 387-417.
6. Diagnostic and Statistical Manual of Mental Disorders, DSM-5, American Psychiatric Association, Washington DC, 2013. pp 189-234.
7. Sadock, B. Op. cit. p 401.
8. Sapolsky, Op. cit.
9. Burns, D. When Panic Attacks, Broadway Books, New York, 2006. pp 7-30.
10. Wilson, E. O. The Meaning of Human Existence, Liveright Publishing, NY p. 141