Fear can neither fight nor fly


We are a vain species to be sure: the pinnacle of creation, the standard against which all else can and should be measured, the judge and jury of any trial. In fairness though, I suppose, we can only use what we were given, and our criteria are of necessity human criteria, so we assess the differences of other creatures in the only way we think is reasonable. Their brains are not as highly developed as ours, so they could not possibly view the world the way we do; they cannot appreciate the arbitrary finitude of their existence, nor the inevitability of their own deaths, living (as we have assumed they do) in an eternal present. They cannot think like us -if they think at all- and so how could they possibly draw conclusions about the ultimate effects of actions either from or on others – or for that matter even on themselves? In short, animals are not us.

In the past, at least, it seemed obvious that although we shared some features with animals, they were by and large only superficial and merely served to illustrate why we were superior. More recently, however, we have found we are able to appreciate more parallels with them: use their reactions, their physiologies, as crude guides to indicate, if not mirror similar states in ourselves. And even the more execrable experimentations that were first performed more out of idle curiosity and then with more directed intent are now being slowly modified to reflect a growing awareness of a shared kinship in emotional reactions.

We are now beginning to search for animal homologies with our own in areas in which we had hitherto not felt their emotions -if they had any- played much of a role. Mindless cause-and-effect explanations avoided any embarrassing comparisons with how we might be expected to react in similar circumstances.

When, aeons ago, I was studying biology in university, it was taken for granted that there was a simple and obvious explanation for population variations in predator-prey relationships for example. In years where there was adequate forage for the mother -deer, let’s say- more babies were produced. And so in turn, more predators could find food, decided to reproduce as well, and everybody was happy. But if in another year, that situation reversed and the forage for deer was decreased, then the prey mothers ‘decided’ to produce fewer offspring and then there were too many predators for the food available so their reproduction rates declined in tandem. As I said, the explanation was obvious: it was clearly an objective matter of supply and demand; no need to complicate the equation with emotional responses of the animals involved: they likely had none. Chess pieces do not require anything more than rules and a suitable board to serve their purpose.

We, on the other hand, would certainly be emotionally affected under similar circumstances -at the very least, stressed, but more probably seek some form of agency and control. Failing that, or if circumstances did not allow any say in the matter, maybe lapse into what we now describe as PTSD -post traumatic stress disorder. But we are humans, after all; we process the happenings in the world differently with our advanced brains; we ‘do not go gentle into that good night’ in the words of a very human Dylan Thomas.

And yet, the PTSD reaction to stress -especially stress over which we have little or no control- must have come from somewhere; surely there is an analogue in the animal kingdom. In my early years of education, I have to admit that I didn’t question the cause-and-effect explanations that seemed to work; I assumed that what we were learning had been vetted for us and I was all too willing to write whatever answers were required to pass the exams and save any questions until after graduation. And then, of course, Life and career intervened and the niggling questions that had occurred to me at the time, were buried like items in a long-forgotten midden.

Occasionally, now that I can feel the leaves dropping from my own branches, my embarrassment surfaces if I trip accidentally upon a pile of questions patiently composting in my mind. One such stumble was into an essay written by the science journalist Sharon Levy: https://knowablemagazine.org/article/living-world/2021/do-wild-animals-get-ptsd

She writes that there is a growing body of evidence showing that ‘fearful experiences can have long-lasting effects on wildlife and suggesting that post-traumatic stress disorder, with its intrusive flashback memories, hypervigilance and anxiety, is part of an ancient, evolved response to danger.’ For example, ‘levels of the stress hormone cortisol in mother hares fluctuated with predator density, peaking when predators were most numerous… And heightened stress hormone levels were also passed from mothers to daughters, slowing the rates of hare reproduction even after predators had died off and abundant vegetation was available for hares to eat. This explains why the hare population remains low for three to five years after predators have all but vanished.’

So the effects of the stress seem to outlast the stressful conditions -results shown in various animals. And ‘all mammals and birds, fish, even some invertebrates — share a common basic structure, and common responses to terror or joy. The brain circuitry that signals fear and holds memories of terrifying events lies in the amygdala, a structure that evolved long before hominids with bulging forebrains came into being… The amygdala creates emotional memories, and has an important connection to the hippocampus, which forms conscious memories of everyday events and stores them in different areas of the brain… Brain imaging studies have shown that people with PTSD have less volume in their hippocampus, a sign that neurogenesis — the growth of new neurons — is impaired. Neurogenesis is essential to the process of forgetting, or putting memories into perspective. When this process is inhibited, the memory of trauma becomes engraved in the mind.’

A similar pattern of suppressed neurogenesis is being identified in wild creatures living in their native habitats. Clearly, it would seem that ‘PTSD has deep evolutionary roots, and that some of its symptoms arise from adaptations — like a heightened state of alert — that allow individuals of many species, including our own, to manage danger. So perhaps PTSD, rather than being maladaptive as some psychiatrists and psychologists maintain, is more of an adaptive behavior to show these extreme reactions in this particular context, because that increases your survival… The brain of someone with PTSD, he [David Diamond, a neurobiologist at the University of South Florida] says, “is not a damaged or dysfunctional brain, but an overprotective brain. You’re talking about someone that has survived an attack on his or her life. So the hyper-vigilance, the inability to sleep, the persistent nightmares that cause the person to relive the trauma — this is part of an adaptive response gone awry.”’

Unfortunately, there remains a stigma to PTSD -as if it bespeaks an inability to deal properly with stress -a cowardly reaction perhaps. And yet, as Liana Zanette, a behavioral ecologist at the University of Western Ontario suggests, ‘if patients can understand that their symptoms are perfectly normal, that there is an evolutionary function for their symptoms, this might relieve some of the stigma around it so that people might go and seek treatment.’

Indeed, understood in its evolutionary context, there should not be any stigma, merely an understanding that fear can neither fight nor fly; it must be understood and rectified: healed. Even wounds can heal…

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