“There’s a one-in-a-million chance of that actually happening.”
Certainly you’ve heard that before. It’s a commonly-used hyperbole to describe how the likelihood of some event occurring is so exceptionally low that it’s not even worth considering. The classic example is getting struck by lightning. According to the US National Weather Service the odds of an average American getting struck by lightning in any given year is roughly one in 500,000 – one in half a million. With odds that low, most people don’t go about their daily lives worrying about it. Contrarily, the odds of winning the US nationwide “Powerball” lottery is much, much lower: somewhere in the realm of one in 100 million per ticket assuming a true random distribution of numbers. Still, when the Powerball lotto hits a threshold where it’s making the 5 o’clock news (usually around $100-150 million US dollars), many, many people – including those who don’t habitually play the lottery – line up at convenience stores nationwide to play their numbers. And while I couldn’t find reliable information on the incidence of play of the LOST numbers from 2004 to present, the basic idea for most is the same: they acknowledge that, while the chances of winning are very low, they’re worth exploring.
Fair enough. But for a good deal of folks it goes beyond that. The ticket, in-hand, sparks a rush of serotonin wave-riding fantasies about what one will do not if but when he or she wins the mega-millions: what friend will get a new Ferrari as a birthday present, what relative will get a new house on the beach, what size yacht one would buy, what unspeakable thing one would do to one’s boss upon quitting, it goes on. And while that fantasy and the good feelings that come with it might be worth the dollar or two for a series of numbers, many take it beyond that by purchasing 20, 50 or even 100 numbers for a dollar apiece. Some do this alone, some do it in pools at the workplace. The end result is – except for that one, ecstatic person – always the same, though: disappointment when none of the array of number combinations selected end up being the one called. “How could I lose?” they think. “I picked so many numbers! I had to win!”
This is a simple example of a logical fallacy that can silently plague one’s thought process without even being aware of it: the Appeal to Probability. The fallacy is the idea that just because something can happens means it must happen. One interpretation of the Appeal to Probability is Murphy’s Law: “anything that can go wrong will go wrong.” While Murphy’s Law can be a good tool to pro-actively troubleshoot potentially destructive flaws when designing or constructing any major project, retro-actively it’s employed as a logical fallacy to excuse unexpected circumstances instead of striving to understand why they happened: “of course I got stuck in traffic on the way to my big job interview. That’s Murphy’s Law for you!”
In fact, the above hypothetical person might have anticipated the traffic jam based on normal patterns, looked up traffic information before heading out, or at least planned an alternate route if he hit troubles. Instead he hasn’t learned from his experience and will likely make the same mistake again under the assumption that he has no control over the situation. This attitude, when taken in regard to all aspects of one’s life, can manifest as a hallmark pathology of clinical depression called “learned helplessness” in which a person is reduced to inaction due to the belief that he has no capacity to affect any positive changes in his life and that “punishment” or bad things happening to him are not related to anything he does or does not do.
Yet not everyone takes it that far. In fact, isn’t it healthy to not concern oneself with every little unlikely thing in the world? Most folks don’t go about their daily lives in constant fear of getting struck by lightning. Still, we have measures of reducing that likelihood: avoid being outside during thunderstorms. Don’t go golfing in the rain. Don’t stand atop a mountain trying to mount a radio antenna when lightning is in the area. These are all things we consider to make sense and to be prudent. But then the Appeal to Probability kicks in when the unlikely event is made evident as being possible: when one is in the pool of 1 in 600 or so that will come to know someone struck by lightning in his or her lifetime. Think it sounds silly? How many times have you thought – or been told – something along the lines of “my aunt slipped and fell on the ice last week so I’d better be careful.”
Though the danger of slipping and falling on the ice has not changed since Hypothetical Aunt had an accident – or, more accurately, since you heard about Hypothetical Aunt’s accident – it suddenly seems to be much more clear and present. It’s not even limited to personal anecdotes, either: how many times have you heard on local TV news the phrase “what you don’t know about [common household object] may kill you!” As absurd as the soft news consumer reports are, they’re still with us headed into 2010. Why? Because they work: they successfully trick people into believing not that there is an exceptionally unlikely danger of, say, dying by a hot waffle iron falling on your head, but that said danger is just about ready to strike them at any second. And enough people believe that to keep watching to find out what other horrible thing might happen to them because it happened once to someone, somewhere.
And there’s the rub, isn’t it? Why do we have probabilities on exceptionally unlikely events? Because, with 300 million people in the US and almost 7 billion worldwide, exceptionally unlikely events do sometimes happen to someone, somewhere. The NWS estimates that roughly 600 Americans do, in fact, get struck by lightning each year. 600 out of 300,000,000. That huge Powerball jackpot? Of the tens or maybe hundreds of millions of numbers played, one is bound to belong to the hands of a winner before long. One person out of 300 million. And that keeps the game going for everyone else.
The fact is, in the on-average 80 years the average person walks this earth, several exceptionally unlikely things are just bound to happen to him. I still recall one particular thing when I was only about 12 years old. I was playing basketball with friends of mine. When I retrieved a ball that had rolled down the driveway about 40 feet from the hoop, I lazily punted it back. Completely without my intention to do so, it went right through the net. I could try that same shot – as an adult – a thousand times and not replicate it. But it still happened. Does this mean I squandered a burgeoning career at foot-basketball? No, it just means that in that case the very unlikely outcome actually happened. As it does sometimes.
And that thought can be frightening. When any danger becomes perceived – however unlikely – the natural reaction is to try to avoid dangers that one can control in favor of those one can’t control, even if the uncontrollable danger is much more likely. Probably the most poignant example of this is the anti-vaccination movement (I will not link anything here because I do not want traffic from this blog going to any of their web space). At the core is the belief that vaccines are “dangerous” or contain “toxins” or – most popular in the early part of the 2000s and still a prevalent reason cited despite being disproved in more ways than 99% of false scientific hypotheses are before dismissal – the idea that there is a link between vaccination and autism. Of course, if vaccines were perfectly harmless 100.00% of the time, there would be no issue and the movement would never gain traction. Unfortunately, rare complications can happen. A botched injection might cause complications. The patient might unwittingly have Guillian-Barre Syndrome and the vaccine might set off a severe autoimmune reaction. So those in the anti-vaccine camp believe that vaccines are, by nature, wrong and should be avoided.
But this isn’t a rational reaction. GBS is tragic but quite rare, affecting only 1 in 100,000 people. On the other hand, roughly 1 in 8,000 Americans will perish from influenza each year, with most being quite young or elderly. Based on that alone the decision to not vaccinate seems foolhardy. When one considers the extensive suffering a young child with an incomplete immune system might undergo in successfully battling the flu it seems even more ridiculous. Still, while the anti-vaccine movement has struggled to gain momentum in the US, it is making headway, and in the UK and Australia it is endemic.
It’s not just related to the flu vaccine, either. Many have refused to give the MMR vaccine against measles, mumps and rubella to their children out of fear for the now-thoroughly-disproved link with autism. Consequently, as herd immunity has failed, measles rates have skyrocketed in the UK over the past decade. How does this happen?
The problem is the final part of the Appeal to Probability fallacy: that which is out of sight must be out of mind. Through advances in late 20th century medicine, measles became a disease of the past in the developed world. Unfortunately, those in the anti-vaccine camp and those who believe them assume on some level this means that measles is gone forever, much like smallpox or the Black Plague (neither of which, by the way, are really gone, but I won’t get into that here). The opposite side of the coin that any perceived danger is bound to happen is that any danger that is not perceived is out of the question. Still, the data speak for themselves and measles is making a comeback like it’s 1968 and it’s Elvis Presley. The lesson is that just because a danger is not perceived doesn’t mean it’s not still there if the conditions are right. This is also the trap that global warming denialists fall into, but, once again, I’ll save that for another time.
But wait, didn’t I say above that listening to those horrible local TV news excuses for journalism that inform their audience of the dangers of common household items are playing on that same logical fallacy? Didn’t I just say that what’s out of sight should be out of mind? Well, not really. True, you should be no more afraid of your blender today than you were yesterday, assuming you remember to lick the batter when it’s turned off. However, there are other things – progressive diseases, for example – that should be carefully considered even if they’re not immediately obvious. The reason for this is that many such diseases (most types of cancer being a good example) for which the prognosis is much better if they are detected and treated early on. Amid fears that too much screening might be a bad thing (as this is still a quite controversial issue I won’t link anywhere for it and you may make your own choices), the best course of action is to consider one’s specific situation, including health and family history. Communicable diseases that can be prevented should be prevented. Don’t stand outside in bare feet waving around HAM radio antennas in thunderstorms. Buy that lotto ticket every now and then if you wish but don’t expect to win. And remember, the only thing that stays in Vegas is your money.
Careful consideration is the key to successful risk-benefit analysis and successful risk-benefit analysis is the best way to a happy, productive life. Read about everything you can before you do it. And hey, don’t take my word for it: ask someone you trust instead of taking advice from celebrities and talking heads paid to make you afraid. Experts are experts for a reason and – trust me on this one – scientists aren’t nearly as evil as every 80s movie ever would have you believe. Lookin’ at you, Project X. Oh, and when some seemingly very unlikely event happens to you, think twice about how well you could have planned against it before you go complaining about old Murphy. He gets a bad rep, after all.('’) delicious