Excerpt from Dr. Stuart Shanker’s Latest Book Restoring Resilience
Towards the end of a life spent researching stress, famed Canadian-Hungarian endocrinologist and researcher Hans Selye observed: “Everyone knows what stress is, but no one really knows” (1956). You could say the same about gravity. In a 1976 interview Selye reiterated exactly that point. We describe gravity as a force of attraction between any two bodies without really knowing what this force is. Much the same can be said about stress.
We regard stress as a force that wears us down, and yet we are unable to explain what that “force” is. Maybe that’s why the very term “stress” makes us anxious. Nothing could be more worrying than the thought that an invisible and negative force is bearing down on us, wearing us out. But worrying about stress is about as productive as worrying about gravity. In fact, gravity is itself a stress and yet another thing to worry about.
The truth is, the definition of stress is relatively straightforward: It is anything that requires us to burn energy. Take the case of noise, which we now know can be immunotoxic. There is an acoustic startle reflex running from the cochlea to the midbrain, which is activated by a loud or unexpected noise. The noise is registered as a threat, causing the release of adrenaline so as to provide the energy needed for escape. Heart rate, blood pressure and breathing rate all go up so as to deliver glucose and oxygen to major muscles in the limbs and trunk. Meanwhile, there is a decrease in gastrointestinal activity and the immune system. The body is now primed to fight-or-flee.
We can apply the same basic model to explain other domains of stress, such as emotional, social, and cognitive. Sudden fear or anger can trigger the same physiological wave as adrenaline is released to provide the energy needed for “guarding”: that is, tensing muscles in the trunk to provide self-protection and in the limbs to escape or fight back. A similar neurophysiological wave occurs when we concentrate on a difficult problem, or by social confrontation or loneliness: the entire body tenses up.
We are bathed in stress even before we are born. The stress of chemicals penetrating the blood-brain barrier. Even high levels of maternal stress can cause a sharp rise of stress-hormones in the foetus. Stress is a universal constant.
