You’re cruising along at 39,000 feet listening to your favorite iTunes playlist. It’s been a long week and you’re feeling relaxed, knowing you’ll soon be home. Suddenly, the plane is shaken by turbulence, first rocking side to side and then dropping briefly like an elevator. Your instinctive reaction is one of fear; the plane seems out of control, about to drop from the sky. You think back to the article you read on turbulence just last week. It said that the conclusion of pilots and aviation safety experts was unanimous; statistical danger to passengers from turbulence was next to zero (as long as your seat belt is securely fastened!). You double check your seat belt but still can’t shake that feeling that you are in danger and an ominous event is ahead.
Why is it that human beings are so tuned to rely on personal sensory data and observation to establish facts, assess risks and make decisions? Why does this personal observation often trump scientific evidence as well as data collected by sensitive machines? How does this propensity hold people back from being more effective decision makers?
The answer, in part lies in our evolutionary history. For most of our existence as a species we lived in a natural world where our senses provided the best means for survival. Second guessing these senses was usually a poor strategy. Is that a tiger lurking in the grass? Probably better to err on the side of “yes”. Walking down this steep hillside is making me feel unsteady. Am I in danger of falling and hurting myself? Probably better to abandon my journey now.
But these same skills that served us well in a prehistoric environment created significant limitations for advancing our state of knowledge and understanding of the complex, natural world around us. Without scientific knowledge and instruments, in addition to his senses, prehistoric and ancient man relied on myth, folklore and superstition to explain a host of natural phenomena. This led to a host of misunderstandings about a wide range of phenomena from fertility to the weather to the yield of plantings.
Much early progress in the advancement of knowledge stemmed from augmenting the basic sensory capabilities of humans. The invention of the telescope in the 17th century extended man’s ability to observe and understand distant objects in the universe. It led to a breakthrough in understanding the motions of celestial bodies and enabled the heliocentric view of our solar system.
While the telescope augmented human vision for distance, the microscope enabled the study of tiny objects. It’s invention led to a broad array of landmark discoveries including cells, microorganisms, the germ theory of disease and genetics. Instrument driven advancements in medicine included x-rays (allowing vision through solid objects) and the stethoscope (enabling hearing for improved clinical observation).
Scientific instruments, along with an accumulated body of scientific knowledge, enabled people to make more accurate and precise judgements about the natural world. But it required humans to put their instinctive “naked” observations to the background and trust instruments as an improved source of “truth”. Is this patient ill? My gut tells me yes, but this x-ray indicates no. Will it rain tonight? Should I plant these crops? The clouds say no, but the Doppler radar says yes.
A large body of human progress has been driven by people putting their instincts on hold, accepting the improved capabilities of scientific instruments and knowledge to guide them. Unfortunately, this is by no means consistent or universal. A great example involves airplanes. A phenomenon can occur where reduced visibility causes a pilot to lose sight of the horizon. Under these conditions, the pilot can become disoriented, incapable of determining whether the plane is banked or flying level. If he relies on his vision or inner ear as a guide, he can mistakenly pilot the plane into a “death spiral”, causing a tragic crash. This is what experts believed happened to JFK Jr. on his fatal flight in 1999.
Instead of relying on vision and one’s inner ear, experienced pilots are trained to ignore their natural senses and rely on their speedometer, altimeter and artificial horizon gauge. Together these three instruments tell the pilot whether he is flying level or heading directly into land or sea. But the instinct to override these gauges when presented with conflicting feedback from natural senses is overwhelming. And unfortunately, many a pilot has met a similar fate to JFK Jr. due to this tendency.
Just as we can reject the readings of scientific instruments, we tend to be skeptical of scientific findings that are not easily observed. Nobody questions Newton’s findings regarding gravity. While it is not a visible “thing”, it’s effects are readily observable. On the other hand, evolution is not easily visible and is unintuitive. It has taken place over billions of years, a time frame that is not personally observable. Nobody needs to be convinced of the power of heat to burn human skin. One touch of a stove is enough to create lifelong knowledge of the science of thermodynamics for a small child. However, convincing people of the link between sun exposure and skin cancer is a more difficult task. The lack of immediate feedback or observable danger leads to a false sense of security.
Evolution has equipped us with some marvelous senses that allowed us to survive in a hostile primitive environment. Unfortunately, these senses interfere with our ability to function optimally in a complex, modern world. They cause us to overweight minimal risks and underweight serious ones. They lead us to ignore evidence and data that seems to conflict with our instincts or personal observations.
There is no simple answer to this problem. Our hard wiring is strong, built over millions of years to ensure our survival. However, as with all negative tendencies, it all starts with awareness. When evaluating evidence, and feeling skeptical, consider the nature of the underlying data. Is it something tangible and observable, or measured through instrumentation and analysis? Is the analysis based on accepted scientific principles and performed by unbiased parties with no conflict of interest?
Being able to think critically about evidence and being able to check one’s tendency to overweight personal observation can be a big benefit to any professional. It can allow for better assessment of risks, better judgements and improved decision making.