Your brain on the scientific method

Coffee is good for you. Coffee is bad for you. Broccoli prevents cancer. Broccoli causes cancer. We are all familiar with the sense that we are constantly being pulled in a million different directions by scientific studies that seem to contradict each other every single day. When trying to make decisions about whether or not to drink coffee, we might be bombarded with equal amounts of data on both sides, half of the articles proclaiming that coffee is a miracle cure and half of the articles proclaiming that it is a death sentence.

Recently, John Oliver, celebrated British comic and host of the popular show Last Week Tonight, confronted the issue of media representation of scientific studies in a welcome and hilarious segment on his show. In a humorous yet searing look into the media’s dealings with science, Oliver points out that science is imperfect and that this fact is important but delicate and needs to be handled in the right way. Instead, he argues, the media turns science into “morning show gossip.” Indeed, Oliver poses the all-important question: “After a certain point, all that ridiculous information can make you wonder, is science bullshit?”

Oliver lists a number of important and irritating ways in which some media sources contribute to mass confusion around real science, which sometimes leads to tragic dismissal of scientific fact that can harm people’s health and wellbeing. But the problem is much deeper than media “sensationalism.” The problem, we believe, actually lies at the heart of the ways in which the scientific process inherently contradicts the ingrained ways of thinking that exist in every human brain. Perhaps it is not only the media that’s causing confusion and false scientific beliefs among perfectly well-educated and reasonable Americans. So what is going on here?

The fundamental problem with any individual’s ability to understand and accept science is two-fold: (1) that science proceeds by disproving rather than proving and (2) that science generally refuses to assert causality with any degree of absolute certainty. These two features of the scientific method are fundamentally antithetical to the way in which the human brain instinctively processes information and formulates conclusions.

Extensive research in both psychology and neuroscience has demonstrated just how stubborn our brains truly are. Once we believe something, our brains do everything they can to reinforce that belief and ensure that it is not shaken. Confirmation bias, a well-known psychological phenomenon, is a perfect example of this fact. Confirmation bias refers to the phenomenon in which new information is interpreted in the service of previously existing beliefs. In general, new information will be filtered and processed by our brains in order to confirm beliefs we already have. New information that conflicts with our beliefs is generally eschewed, as accepting it would create cognitive dissonance, an uncomfortable psychic scenario in which some information we have accepted as true runs counter to core beliefs we already have. Such beliefs may often form a key part of our identities. Neuroscience studies using imaging techniques such as fMRI largely confirm these psychological notions, often by revealing activation of our fear centers when presented with information that directly contradicts what we have previously held to be true.

The problem here is that science is all about disproving previously held beliefs. Science proceeds through a process of falsification, in which experiments are repeated ad nauseam until the initial effect can be disproven and a new theory can emerge. In some cases, replication of experiments reproduces the exact same results over and over again. Only once an experiment has been replicated many times with the same results can scientific theory become scientific fact. As you can probably see, we have a serious problem here. Science by its very nature asks us to be willing to constantly dismiss old ideas in favor of new ones. But the human brain by its very nature asks us to hold on tightly and stubbornly to any idea we have already formed. Our instincts are simply not set up in a way that allows us to go merrily along with scientific falsification without a fight.

The second feature of science that clashes with fundamental human instinct is its reluctance to establish cause. If you carefully examine statements by scientists in the press, you will notice that they are frustratingly hesitant to ever say that “A causes B” or, for that matter, that “A definitively does not cause B.” This is because it is actually extremely difficult to establish causality in science – more difficult than most people realize. The only way to establish true causality in science is to observe what’s called the “counterfactual.” The counterfactual is what would happen in an alternate universe if one aspect of the environment were changed but everything else stayed the same. If you want to know whether drinking orange juice caused your rash, the best way to establish this for sure would be for you to go back in time, not drink the orange juice, and then see whether you still got a rash. Because every circumstance was exactly the same, except whether or not you drank the orange juice, if you still developed the rash, you could be 100% certain the orange juice did not cause it.

Scientists have devised very clever and advanced methods of trying to approximate the counterfactual in experiments without the use of a time machine. However, they are by no means perfect and so scientists are very careful never to express 100% certainty about causality. The problem, again, is that human beings are not wired to accept this. A number of studies, again in both psychology and neuroscience, have demonstrated that human beings are extremely uncomfortable with any situation in which a cause is unknown. So we often fill in the blanks and invent causes when they don’t exist. This could explain why many parents are so quick to accept the notion that vaccines cause autism – no clear cause for autism has been established in science and so people are uncomfortable. At the same time, scientists are not very reassuring when they say things like “There is no evidence that vaccines cause autism.” Wouldn’t it be better if they would just say “We are 100% certain that vaccines do not cause autism”? The problem with this statement is that it technically does not represent the scientific method very well. But your brain doesn’t care about the scientific method when you’re desperately trying to make sense of a complex, often senseless world, in which many things seem to happen for no reason.

So when looking at the reasons behind public misperceptions of science, the media is certainly an important source. But we should be careful not to blame everything on journalists. One of the greatest enemies of the scientific method sits just inside the heads of scientists and non-scientists alike. We can overcome resistance to scientific fact only by being more aware of the devious ways in which our own minds can work against us.

Featured image credit: Brain by Jesse Orrico. CC0 public domain via Unsplash.