Seeing Causality

In Thinking Fast and Slow Daniel Kahneman describes how a Belgian psychologist changed the way that we understand our thinking in regard to causality. The traditional thinking held that we make observations about the world and come to understand causality through repeated exposure to phenomenological events. As Kahneman writes, “[Albert] Michotte [1945] had a different idea: he argued that we see causality just as directly as we see color.”

The argument from Michotte is that causality is an integral part of the human psyche. We think and understand the world through a causal lens. From the time we are infants, we interpret the world causally and we can see and understand causal links and connections in the things that happen around us. It is not through repeated experience and exposure that we learn to view an event as having a cause or as being the cause of another event. It is something we have within us from the beginning.

I try to remember this idea of our intuitive and automatic causal understanding of the world when I think about science and how I should relate to science. We go through a lot of effort to make sure that we are as clear as possible with our scientific thinking. We use randomized controlled trials (RCT) to test the accuracy of our hypothesis, but sometimes, an intensely rigorous scientific study isn’t necessary for us to make changes in our behavior based on simple scientific exploration via normal causal thinking. There are some times where we can trust our causal intuition, and without having to rely on an RCT for evidence. I don’t know where to draw the line between causal inferences that we can accept and those that need an RCT, but through honest self-awareness and reflection, we should be able to identify times when our causal interpretations demonstrate validity and are reasonably well insulated from our own self-interests.

The Don’t Panic Geocast has discussed two academic journal articles on the effectiveness of parachutes for preventing death when falling from an aircraft during the Fun Paper Friday segment of two episodes. The two papers, both published in the British Medical Journal, are satirical, but demonstrate an important point. We don’t need to conduct an RCT to determine whether using a parachute when jumping from a plane will be more effective at helping us survive the fall than not using a backpack. It is an extreme example, but it demonstrates that our minds can see and understand causality without always needing an experiment to confirm a causal link. In a more consequential example, we can trust our brains when they observe that smoking cigarettes has negative health consequences including increased likelihood of an individual developing lung cancer. An RCT to determine the exact nature and frequency of cancer development in smokers would certainly be helpful in building our scientific knowledge, but the scientific consensus around smoking and cancer should have been accepted much more readily than what it was. An RCT in this example would take years and would potentially be unethical or impossible. Tobacco companies obfuscated the science by taking advantage of the fact that an RCT in this case couldn’t be performed, and we failed to accept the causal link that our brains could see, but could not prove as definitively as we can prove something with an RCT. Nevertheless, we should have trusted our causal thinking brains, and accepted the intuitive answer.

We can’t always trust the causal conclusions that our mind reaches, but there are times where we should acknowledge that our brains think causally, and accept that the causal links that we intuit are accurate.