As a clinical psychology student with a mathematical approach, I have noticed that people tend to prefer to attribute zero (0.0) or near-zero, or, unity (1.0) or near-unity probabilities to their thoughts about others, themselves and their circumstances. People like certainty, whether it is positive (1.0) or negative (0.0). Both mean there is little doubt, little "up in the air" to make us worry. People like it so much, they will gravitate towards it even when it isn't there. For example, in conversation with a spouse, how often will someone say "You always ...", when what is meant is that "You often ..." or "You usually ... " These don't pack the same punch as "You always ..." do they? Think of this zinger: "You sometimes misinterpret what I say!!!" compared to: "You always misinterpret what I say!!!" My bet is, the first one is true for most married couples, while the second one is has more impact, but isn't true. People gravitate towards certainty, sometimes more out of convenience than honest estimation.

The clinical relevance of this phenomenon can be highlighted through the concepts used in Cognitive-Behavioural Therapy approaches (CBT; developed by Dr. A.T. Beck and colleagues). CBT has focused the efforts of therapists and counsellors towards helping people think in more truthful ways, in more balanced ways, to get out of chronic depression, for example. One of the ways CBT redresses unhealthy, incorrect thinking is by identifying and redressing "cognitive distortions". These are thoughts that people have deep down that are skewing their approach to life and to the world. An example would be: "Everybody hates me". Is this really true for most people who think it? There are names for cognitive distortions like these: "all-or-nothing thinking", "black-and-white thinking", and overgeneralization would be examples. These types of cognitive distortions, examples I have selected, also happen to correspond to that need people have for comforting certainty. Even if it is a "negative" certainty, at least it is predictable, and this reduces how hard it is to live with "people might like me ..." with something reliable, though unfortunate, like "people don't like me".

Mathematically, my colleague Dr. R.W.J. Neufeld and I have defined a metric for "unpredictability" when faced with a potential threat. The specifics are available among my profile page documents (Shanahan & Neufeld, 2010, online supplement), but essentially, there are two relevant quantities. Expected threat E(t) is an objective mathematical calculation of the likelihood of an undesirable, stress-generating event occurring. The variance in event magnitude, Var (e.m.), represents how much a person facing the potential for an undesirable event is likely to be affected by the occurrence of the event, in terms of how much what could possibly happen will stress them out ahead of time. We theorize that this depends on how much variation there is in what could happen. With certain simplifying assumptions, it can be shown that Var (e.m.) = E(t) • (1- E(t)), or, that Var (e.m.) = E(t) - E(t)^2. Because E(t) is the probability of a threat happening, it ranges from 0.0 to 1.0. Plugging these end values into the formula shows that when E(t) = 0.0, Var (e.m.) = 0.0, or when E(t) = 1.0, Var (e.m.) = 0.0. If Var (e.m.), the amount of possible variation in how much impact something might have upon a person facing a threat or stressor, is equal to 0.0, there is no "unpredictability". If, however, the chances of a threat happening are 50%, or a probability of E(t) = 0.5, then Var (e.m.) = 0.25, is at its maximum value. This curve is shown below.

Unpredictability is Curvilinear as Expected Threat Linearly Increases

The interpretation of this curve is that the range of potential consequences for a given event are broadest, and hence most unpredictable, when there is a 50/50 chance. If we accept that for some people, the unpredictability itself is what they are trying to reduce, the phenomenon of people grasping for certainty beyond what the facts will bear can be explained as unpredictability reduction. The unpredictability is zero in a statement that uses always (probability = 1.0) or never (probability 0.0). The unpredictability goes up the more a situation could go either way, peaking at 50% (probability = 0.5).

The lesson here is that we need to be aware, as frail human beings with tendencies to distort the truth because of short-sightedness, that we may be speaking, thinking, or acting apart from a balanced, healthy, accurate view of probabilities. That is, if we are chronically overestimating or underestimating what might happen, or what is so, we may be taking refuge emotionally in the land of low unpredictability, but at the cost of incorrectly leaving out the chance for something different to occur. One classic hallmark of maturity, of being a grown-up, is not to have to think in extremes all the time, the way young people often do. Tolerance of ambiguity, "living in the middle", can be thought of as a sign that people have built up their ability to function in the face of the unpredictable. The benefit here is that they can manage very well with a more accurate "map of daily probabilities" if they don't run from the discomfort of unpredictability. Isn't that very unpredictability, in its turn, precisely the "thrill of the hunt", the ache and longing of unresolved romance, the very spice of life? The French say "Vive la difference!" to celebrate the difference between the sexes. As enterprising, optimistic North Americans who like to live life between the impossible and the inevitable, I suggest our credo might be: "Here's to the possibilities ..."