I Don’t Know

Those three little words – I don’t know – are something my wife doesn’t like to hear, particularly when asking our family what we would like to eat for dinner. In her opinion, that is simply not a helpful response. Pushing for a more informative answer helps her avoid disappointing us with her dinner choice (or more importantly, hearing complaints about it). This is one way she can deal with the uncertainty of whether such a negative event might happen. Nature’s solution to uncertainty is to use probability.

What is probability? The Merriam-Webster web site defines probability as “the quality or state of being probable” and then defines probable as “likely to be or become true or real”.[1][2] Of course it then goes on to define likely as “having a high probability of occurring or being true” or “very probable.”[3] Those definitions seem a bit circular to me. The Online Etymology Dictionary is a little more helpful, indicating the word likely had a meaning of “having the appearance of truth or fact” around the year 1300.[4] Language can be a tricky thing and is not the intended focus here, so we might have to settle for this last definition for now.

Valid probabilities are numbers between zero and one. A probability of 0 for an event means that the event will not happen, at least in the given context. A probability of 1 means we know it will happen. A probability greater than 0 and less than 1 means we don’t know whether the event will occur. We believe the event is more likely to occur if its probability is closer to 1 and less likely to occur if closer to 0. A probability of 0.5 means the event has an equal likelihood of occurring as not occurring. We know this because the probability of something not occurring is simply 1 minus the probability of it actually occurring. The probability of it not occurring is 1 – 0.5 = 0.5. Keep in mind, the study of probability cannot be fully described in one paragraph or even one blog entry, and there are many books on the subject.

An example of probability from nature could be helpful, like when an animal is hungry. Humans are animals, and I am human, so suppose I am the one who is hungry. Also suppose my wife is not currently available to provide dinner (she works hard and deserves a break). Can I immediately eat? First I need to obtain food, assuming I don’t already have some. I have sense organs, including eyes to see with. Suppose I see an object and pick it up to consider eating it. Why do I even have to stop and think? Because not everything is food. If I try to eat something that is not food, I may get sick or even die, and I don’t want anything like that to happen. What does this object I found look like, and why do I care? If it does not look like food, then it may not be food. Similarly, if it does not smell like food or taste like food, then it probably is not food.

The process of an animal trying to sense food and determine whether what it finds is good to eat, is fairly fundamental. It is practiced by most animals, all the way down to at least some single-celled organisms. Why? Humans are supposedly the most advanced species on Earth, and we are not omniscient. Surely, none of the other forms of life on Earth are omniscient. So without perfect knowledge of where to find food, we look for indications of where to find food. Many animals, such as ants or dogs might “follow their nose.” They hope they find food, assuming that food is what they are smelling. Why should a hungry animal choose to go where there seems to be no food instead of going where there seems to be food? There’s the assumption that the smell of food makes it more likely to find food where such a smell is present or stronger than elsewhere. The possibility of getting food is just one reason to try something in spite of uncertainty, with many other motivations such as seeking safety or mating.

This can of course backfire. Since many animals will look for their own kind so they can eat the same thing (if there’s enough food) or maybe to mate, duck hunters might use wooden decoys that look enough like ducks, that real ducks may come visit them. Or an angler fish may dangle a part of itself that resembles a small animal, hoping to lure an unsuspecting hungry fish to where the angler fish can grab it with sharp teeth. At the grocery store, a less successful food manufacturer may make its packaging look similar to the packaging of a more successful product of the same kind, hoping that a shopper will not look too closely when trying to purchase the more successful product.

Physical needs are just one reason to use probability, but this barely even scratches the surface. At least physical needs provide examples of how we may use uncertain indicators to help us find what we want. Being wrong can be inconvenient or even deadly, but we try anyway, especially when success seems likely. For us humans, I think it’s not just a matter of survival, but also a matter of hope. No matter how grim the situation, as long as failure is not certain, we can hope. That can be enough to make success or survival more likely than otherwise.

References

1. https://www.merriam-webster.com/dictionary/probability

2. https://www.merriam-webster.com/dictionary/probable

3. https://www.merriam-webster.com/dictionary/likely

4. https://www.etymonline.com/search?q=likely